Postprocessing Modules
AL52CO
Warning
This module depreciated for flights after 2021-01-12
Process CO concentration from the AL5002 instrument. The instrument provides counts, concentration, sensitivity, and zero. However, the sensitivity and zero step change after calibrations, which propogate through to the CO concentration provided by the instrument. To avoid post-calibration step changes, we assume that the sensitivity and zero drift linearly between calibrations, and interpolate across the step changes to produce smoother sensitivity and zero-offset curves. The CO concentration is then given by
where \(c\) is the count reported by ther instrument, \(z_i\) is the linearly interpolated zero and \(S_i\) is the linearly interpolated sensitivity.
After a calibration, data continue to be flagged for 5 seconds, to allow for calibration gasses to be flushed from the system. Where available, the state of the V1 valve on the Fast Greenhouse Gas Analyser (FGGA) is used to identify and flag span calibrations.
Outputs
- CO_AERO
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: CO_AERO_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Aero-Laser GmbHinstrument_model
: AL5002long_name
: Mole fraction of Carbon Monoxide in air from the AERO AL5002 instrumentstandard_name
: mole_fraction_of_carbon_monoxide_in_airunits
: ppb
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
aircraft_on_ground
- The aircraft is on the ground, as indicated by WOW_IND.co_out_of_range
- The derived CO concentration is considered out of valid range.in_calibration
- The instrument is currently, or has recently been, in calibration. Data should be disregarded.no_calibration
- No calibration has yet been performed. Data should be disregarded.counts_zero
- The instrument is reporting zero counts. This is most likely erroneous.
AirSpeed
Calculates aircraft indicated and true air speeds. Mach number, \(M\),
is calculated from static and dynamic pressures (here \(p\) and
\(q\), derived as PS_RVSM
and Q_RVSM
, in processing
module p_rvsm.py
) using the standard calculation sp_mach
defined in
ppodd.utils.calcs:
Indicated airspeed is then given as
where \(V_s\) is the speed of sound at standard temperature and pressure, and \(P_{std}\) is the surface pressure in the ICAO standard atmosphere.
True airspeed is given as
where \(T_c\) is a TAS correction term, defined in the flight constants, \(T_\text{di}\) is the temperature from the de-iced temperature sensor, and \(T_\text{std}\) is the surface temperature in the ICAO standard atmosphere.
Outputs
- IAS_RVSM
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: IAS_RVSM_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Indicated air speed from the aircraft RVSM (air data) systemunits
: m s-1
- TAS_RVSM
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TAS_RVSM_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: True air speed from the aircraft RVSM (air data) system and deiced temperaturestandard_name
: platform_speed_wrt_airunits
: m s-1
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
mach_out_of_range
- Either static or dynamic pressure out of acceptable limits during calculation of mach number.
BBRFlux
Caluclates the corrected fluxes from the upper and lower clear dome and red dome pyranometers.
Note
Prior to software version 24.3.0, the BBRs were incorrectly labelled as manufactured by Kipp & Zonen. This has been corrected to The Eppley Laboratory inc. from version 24.3.0 onwards.
The thermistors in the pyranometers have a characteristic non-linear temperature dependence due to the manufacturing process. If not corrected for, this can lead to errors in temperature of up to 1 \(^\circ\text{C}\). A quintic equation has been fitted to the manufacturer provided corrections for a range of temperatures, providing a correction between \(-50 ^\circ\) C and \(40 ^\circ\) C to within \(\pm0.07\) \(^\circ\) C.
The polynomial coefficents \(\alpha_0\ldots\alpha_5\) are hard-coded, and take the values
The flux for each dome, \(F_d\), is calculated by subtracting a 10 second running mean of the zero from the signal. The flux is then corrected for temperature sensitivity using
where \(T_c\) is the corrected dome thermistor temperature, and \(\gamma_n\) are the first \(n\) values in the dome constants array.
A threshold value, \(F_{\text{crit}} = 920\cos(\zeta)^{1.28}\), is used to determine whether the dome is in direct or diffuse radiation, with fluxes above \(F_{\text{crit}}\) (or \(F_{\text{crit}} / 2\) for red domes) assumed to indicate direct radiation. This expression for \(F_{\text{crit}}\) approximates the ‘German’ equation (ref?) but is simpler and remains positive at low sun elevations. If the flux is determined to be direct, then the upper radiometers are corrected for the pitch and roll of the aircraft (Ref: M/MRF/13/5):
Here, \(f_r(\zeta)\) is the ratio of of direct:direct+diffuse radiation,
currently assumed to be 0.95
for all solar zenith angles,
\(c(\zeta)\) is a correction term for the cosine effect (Ref: Tech note
8, table 4). The angle between the solar zenith and normal-to-instrument,
\(\beta\), is given by
where \(\phi\) is the aircraft roll, \(\zeta\) is the solar zenith angle, \(\psi\) is the ‘sun heading’, the difference between the solar azimuth angle and the aircraft heading, and \(\theta\) is the aircraft pitch angle. Ref: Tech. note 7, page 10. Prior to this correction, platform relative pitch and roll offsets, determined through flying clear sky box patterns, are added to the instrument-derived pitch and roll. These are given as elements 4 and 5 in the flight constants for each dome.
Outputs
- SW_DN_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SW_DN_C_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: The Eppley Laboratory inc.instrument_model
: PSPinstrument_serial_number
: <str: derived_from_file>long_name
: Corrected downward short wave irradiance, clear domestandard_name
: downwelling_shortwave_flux_in_airunits
: W m-2
- SW_UP_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SW_UP_C_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: The Eppley Laboratory inc.instrument_model
: PSPinstrument_serial_number
: <str: derived_from_file>long_name
: Corrected upward short wave irradiance, clear domestandard_name
: upwelling_shortwave_flux_in_airunits
: W m-2
- RED_DN_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: RED_DN_C_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: The Eppley Laboratory inc.instrument_model
: PSPinstrument_serial_number
: <str: derived_from_file>long_name
: Corrected downward short wave irradiance, red domeunits
: W m-2
- RED_UP_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: RED_UP_C_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: The Eppley Laboratory inc.instrument_model
: PSPinstrument_serial_number
: <str: derived_from_file>long_name
: Corrected upward short wave irradiance, red domeunits
: W m-2
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
roll_limit_exceeded
- The aircraft is in a roll exceeding the specified max roll limit of 7.0 degrees from horizontal.low_sun_angle
- The sun is low relative to the axis of the aircraft, exceeding the maximum allowed limit of 80.0 degrees.flux_out_of_range
- The calculated is outside of the specified allowable flux range [-20.0, 700.0] W/m2
BBRSols
Converts the raw voltages on the BBR channels to physical values via a linear calibration, using coefficients defined in the flight constants. Each radiometer provides a signal, a zero and a thermopile temperature.
Required calibration coefficients are CALUP1S
, CALUP2S
, CALLP1S
,
and CALLP2S
. The forth character in each of these identifies whether the
calibration is for an (U)pper or (L)ower radiometer, and the fifth and sixth
characters indicate whether the calibration is for position 1 (P1) or
position 2 (P2). The first two constants in each calibration array are
\(n_0\) and \(n_1\) linear coefficents for the sensitivity, while
the second two are the linear coefficients for the thermopile temperature.
Outputs
- UP1S
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: UP1S_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: UPP VIS CLR SIGunits
: W m-2
- UP2S
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: UP2S_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: UPP VIS RED SIGunits
: W m-2
- UIRS
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: UIRS_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: UPP I/R SIGNALunits
: W m-2
- UP1Z
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: UP1Z_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: UPP VIS CLR ZEROunits
: W m-2
- UP2Z
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: UP2Z_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: UPP VIS RED ZEROunits
: W m-2
- UIRZ
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: UIRZ_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: UPP I/R ZEROunits
: W m-2
- UP1T
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: UP1T_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: UPP VIS CLR TEMPunits
: degree C
- UP2T
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: UP2T_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: UPP VIS RED TEMPunits
: degree C
- UIRT
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: UIRT_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: UPP I/R TEMPunits
: degree C
- LP1S
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: LP1S_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: LWR VIS CLR SIGunits
: W m-2
- LP2S
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: LP2S_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: LWR VIS RED SIGunits
: W m-2
- LIRS
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: LIRS_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: LWR I/R SIGNALunits
: W m-2
- LP1Z
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: LP1Z_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: LWR VIS CLR ZEROunits
: W m-2
- LP2Z
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: LP2Z_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: LWR VIS RED ZEROunits
: W m-2
- LIRZ
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: LIRZ_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: LWR I/R ZEROunits
: W m-2
- LP1T
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: LP1T_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: LWR VIS CLR TEMPunits
: degree C
- LP2T
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: LP2T_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: LWR VIS RED TEMPunits
: degree C
- LIRT
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: LIRT_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: LWR I/R TEMPunits
: degree C
Flags
Variables in this module use classic, value based flagging.
- UP1S_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- UP2S_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- UIRS_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- UP1Z_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- UP2Z_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- UIRZ_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- UP1T_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- UP2T_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- UIRT_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- LP1S_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- LP2S_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- LIRS_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- LP1Z_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- LP2Z_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- LIRZ_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- LP1T_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- LP2T_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- LIRT_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
BuckCR2
This documentation adapted from FAAM document FAAM010015A (H. Price, 2016).
For further details see the FAAM Met. Handbook.
The core processed data for the Buck CR2 includes the mirror temperature and the volume mixing ratio of water vapour. Prior to September 2016, the water vapour pressure was calculated using using the parameterisation given by Hardy (1998), which is based on the ITS-90 formulations. In September 2016, the data processing was updated to use the Murphy and Koop (2000) parameterisation for water vapour pressure. The vapour pressure over liquid water is now calculated according to
valid for \(123 < T < 332\) K. The vapour pressure over ice is calculated as follows:
valid above 110 K. The water vapour pressure inside the instrument, \(p_{\text{H}_2\text{O,Buck}}\) is calculated using either equation 1 or 2 depending on whether a dew point or a frost point has been observed. Above 273.15 K, a dew point is clearly observed. Below 243.15 K, we can be confident that a frost point is being measured. Between 243.15 and 273.15 K, a dew point is assumed if the mirror has not been below 243.15 K since it was last above 273.15 K and it has been below 273.15 K for less than ten minutes. If the mirror temperature is within the supercooled water regime but has been below 243.15 K since it was last at 273.15 K, or it has been below 273.15 K for more than ten minutes, a frost point is assumed. The fact that these are assumptions is reflected in the measurement uncertainty, described below.
The vapour pressure is converted to volume mixing ratio, \(r_{\text{H}_2\text{O}}\), as follows:
where \(e_f\) is the enhancement factor given by Hardy (1998) and \(p_\text{Buck}\) is the air pressure inside the instrument.
A corrected dew or frost point is calculated, which is slightly different to the mirror temperature, correcting for the difference between the pressure inside the insturment and the static air pressure outside the aircraft. The water vapour pressure outside the aircraft is
where \(p_s\) is the static air pressure. A dew or frost point is then calculated using the Murphy and Koop (2005) parameterisation. Frost points are calculated using an equation given in the paper:
In the the absence of an equation to calculate dew point, a numerical solving routine is used to find \(T_\text{dew,outside}\) from Equation 1.
The uncertainty associated with the Buck CR2 measurements have several sources
The uncertainty associated with the calibration performed at NPL (where applicable). This is derived from the NPL expanded uncertainty and fit to a power law.
The repeatability of the calibration. This is derived from the NPL calibration measurements of different dew points and fit to a power law.
The response time of the instrument and the atmospheric variability. This is based on an assessment of the standard deviation of subsequent readings to give an indication of atmospheric variability.
The uncertainty involved in the interpolation of data between calibration datapoints. This is a function of temperature, increasing below 233.15 K.
The bias associated with the uncertainty about whether there is water or ice on the mirror between 243.15 and 273.15 K. This is calculated using a flagging scheme according to the temperature history of the mirror.
These are combined to produce one uncertainty value for the mirror temperature, which may be propagated through to the volume mixing ratio and the pressure-corrected dew or frost point. Note that prior to software version 0.10.1 the uncertainties are expanded uncertainties. From software version 0.10.1 onwards, the uncertainties are combined uncertainties, for consistency with other variables in the core dataset which have an associated uncertainty.
Outputs
- VMR_CR2
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: VMR_CR2_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Buck Research Instrumentsinstrument_model
: CR2 Chilled Mirror Hygrometerinstrument_serial_number
: <str: derived_from_file>long_name
: Water vapour volume mixing ratio measured by the Buck CR2units
: ppmv
- VMR_C_U
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: VMR_C_U_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 1instrument_manufacturer
: Buck Research Instrumentsinstrument_model
: CR2 Chilled Mirror Hygrometerinstrument_serial_number
: <str: derived_from_file>long_name
: Combined uncertainty estimate for water vapour volume mixing ratio measured by the Buck CR2units
: ppmv
- TDEW_CR2
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TDEW_CR2_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Buck Research Instrumentsinstrument_model
: CR2 Chilled Mirror Hygrometerinstrument_serial_number
: <str: derived_from_file>long_name
: Mirror Temperature measured by the Buck CR2 Hygrometerstandard_name
: dew_point_temperatureunits
: degK
- TDEW_C_U
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TDEW_C_U_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 1instrument_manufacturer
: Buck Research Instrumentsinstrument_model
: CR2 Chilled Mirror Hygrometerinstrument_serial_number
: <str: derived_from_file>long_name
: Combined uncertainty estimate for Buck CR2 Mirror Temperatureunits
: degK
- TDEWCR2C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TDEWCR2C_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Buck Research Instrumentsinstrument_model
: CR2 Chilled Mirror Hygrometerinstrument_serial_number
: <str: derived_from_file>long_name
: Corrected dew point temperature measured by the Buck CR2 Hygrometerstandard_name
: dew_point_temperatureunits
: degK
Flags
Variables in this module use classic, value based flagging.
- VMR_CR2_FLAG
0
:data_good
- Data are considered valid1
:not_controlling
- The instrument is not controlling on a dew point2
:mirror_contaminated
- The instrument is reporting contamination on the mirror3
:in_balance_cycle
- The instrument is in a balance cycle and not recording a dew point4
:data_missing
- Data are expected but are not present
- VMR_C_U_FLAG
0
:data_good
- Data are considered valid1
:not_controlling
- The instrument is not controlling on a dew point2
:mirror_contaminated
- The instrument is reporting contamination on the mirror3
:in_balance_cycle
- The instrument is in a balance cycle and not recording a dew point4
:data_missing
- Data are expected but are not present
- TDEW_CR2_FLAG
0
:data_good
- Data are considered valid1
:not_controlling
- The instrument is not controlling on a dew point2
:mirror_contaminated
- The instrument is reporting contamination on the mirror3
:in_balance_cycle
- The instrument is in a balance cycle and not recording a dew point4
:data_missing
- Data are expected but are not present
- TDEW_C_U_FLAG
0
:data_good
- Data are considered valid1
:not_controlling
- The instrument is not controlling on a dew point2
:mirror_contaminated
- The instrument is reporting contamination on the mirror3
:in_balance_cycle
- The instrument is in a balance cycle and not recording a dew point4
:data_missing
- Data are expected but are not present
- TDEWCR2C_FLAG
0
:data_good
- Data are considered valid1
:not_controlling
- The instrument is not controlling on a dew point2
:mirror_contaminated
- The instrument is reporting contamination on the mirror3
:in_balance_cycle
- The instrument is in a balance cycle and not recording a dew point4
:data_missing
- Data are expected but are not present
CPC
Reports particle counts from the TSI 3786 condensation particle counter. Counts are reported as-is from the instrument; this module only provides flagging information.
Note
Prior to v23.3.0, the CPC included flags for both sample flow and sheath flow. These have been combined into a single flag, and a cloud flag has been added, as CPC data are not valid in cloud. The cloud flag is added by a separate flagging module.
Outputs
- CPC_CNTS
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: CPC_CNTS_FLAGcomment
: Sampled through a modified Rosemount Aerospace Inc. Type 102 Total Temperature Housing.coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 10instrument_manufacturer
: TSI Incorporatedinstrument_model
: Modified Water Filled 3786 Condensation Particle Counterinstrument_serial_number
: <str: derived_from_file>long_name
: Condensation Particle Counts measured by the TSI 3786units
: 1
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
saturator_over_temp
- The saturator temperature is above 6 Cgrowth_tube_temp_out_of_range
- Growth tube temperature is outside the valid range [40.5, 49.5] Coptics_temp_out_of_range
- Optics temperature is outside the valid range [40.5, 49.5] Csample_or_sheath_flow_out_of_range
- Sample or sheath flows are outside the valid range [270, 330]counter_saturated
- Counter has exceeded its saturation value, 1000000
CabinPressure
Derives cabin pressure from a pressure transducer located in the core
console. A polynomial fit, with coefficients provided in the constants
variable CALCABP
, converts DLU counts \(\rightarrow\) transducer
voltage \(\rightarrow\) pressure.
Outputs
- CAB_PRES
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: CAB_PRES_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: Cabin Pressuresensor_manufacturer
: Rosemount Aerospace Inc.sensor_model
: 1201F2sensor_serial_number
: <str: derived_from_file>units
: hPa
Flags
Variables in this module use classic, value based flagging.
- CAB_PRES_FLAG
0
:data_good
- Data are considered valid1
:pressure_out_of_range
- Data are outside the valid range [650, 1050] hPa
CabinTemp
Derives cabin temperature from a sensor located on the right of the core
console. A polynomial fit, with coefficients provided in the constants
variable CALCABT
, converts DLU counts \(\rightarrow\) raw
\(\rightarrow\) temperature.
Outputs
- CAB_TEMP
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: CAB_TEMP_FLAGcomment
: Should be considered a qualitative measure only, due to lack of calibration and proximity to the core consolecoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: Cabin temperature at the core consolesunits
: degC
Flags
Variables in this module use classic, value based flagging.
- CAB_TEMP_FLAG
0
:data_good
- Data are considered valid1
:sensor_uncalibrated
- Indicates that the sensor is considered to be poorly calibrated. Temperatures are to be considered qualitative.2
:data_missing
- Data are expected, but are missing
DryMach
This module calculate a dry-air Mach number using RVSM pressure measurements.
Dry-air Mach number, \(M\), is given by
The module also provides the parameter SH_GAMMA
, which is the ratio of
specific heats at constant pressure and constant volume, along with
uncertainty estimates for MACH
and SH_GAMMA
. The former is the
combined uncertainty of the uncertainy in BAe report 127 and the
uncertainty in gamma, while the latter is a constant and assumed to be
0.003, which is derived from the impact of neglecting humidity at the
highest expected VMR of 35000 at 1100 hPa.
Outputs
- MACH
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: MACH_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Dry air Mach derived from and RVSMunits
: 1
- SH_GAMMA
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SH_GAMMA_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Ratio of specific heats at constant pressure and constant pressureunits
: 1
- SH_GAMMA_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SH_GAMMA_CU_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Uncertainty estimate for SH_GAMMAunits
: 1
- MACH_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: MACH_CU_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Uncertainty estimate for MACHunits
: 1
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
aircraft_on_ground
- The aircraft is on the ground, as indicated by the weight-on-wheels indicator
ElectricFieldJci140
This module reports the raw counts from the JCI static monitor on the core console.
Outputs
- EXX_JCI
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: EXX_JCI_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: Raw data from the Fwd Core Console JCI static monitor, static signalunits
: 1
Flags
Variables in this module use classic, value based flagging.
- EXX_JCI_FLAG
0
:data_good
- Data are assumed to be valid and representative of the physical quantity measured1
:uncalibrated_counts
- Indicates this data is raw, uncalibrated counts from the DLU. Use with caution.
ElectricFieldZeus
Provides the electric field measurement from the Zeus instrument. No processing is actually performed, the data reported by the instrument is simply passed through to the output, with the addition of a flag.
ZEUS is a window mounted static mill created by the MetOffice OBR group. It uses a sensor designed by Dr John Chubb (JCI 140) made by Hearn Morley/Fraser Anti-Static and an Arduino Uno to digitize the analogue signal. It is fitted in SW1.
Outputs
- EXX_ZEUS
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: EXX_ZEUS_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Met Office OBR, Hearn Morley, Fraser Anti-Staticinstrument_serial_number
: 12230002long_name
: Electric field measured by the Zeus instrumentunits
: kV m-1
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
aircraft_on_ground
- Aircraft is on the ground, as indicated by weight-on-wheels
GINWinds
Calculates a horizontal wind vector from the aircraft true air speed, derived from the air data computer, and the speed and heading from the GPS-aided inertial navigation unit.
The RVSM derived TAS is corrected to account for a discrepancy with the turbulence-probe derived TAS according to
where \(M\) is the Mach number, given by
where \(T_\text{DI}\) is the air temperature measured in the deiced housing.
The resulting corrected TAS may also be modified with a scaling correction,
specified in the constants as GINWIND_TASCOR
.
The eastward and northward components of TAS, \(\text{TAS}_u\) and \(\text{TAS}_v\) are given by
Where \(\theta\) is the aircraft heading, which may be corrected with
an offset given in the constant GIN_HDG_OFFSET
to account for any
misalignment of the GIN to the aircraft axis. The horizontal winds
\(u\) and \(v\) are then given by
where \(u_G\) and \(v_G\) are the eastward and northward components of the aircraft speed, reported by the GIN.
Outputs
- U_NOTURB
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: U_NOTURB_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: Eastward wind component derived from aircraft instruments and GINstandard_name
: eastward_windunits
: m s-1
- V_NOTURB
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: V_NOTURB_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: Northward wind component derived from aircraft instruments and GINstandard_name
: northward_windunits
: m s-1
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
roll_exceeds_threshold
- No flag description provided.
GeneralEastern
Processing module to calculate Dew Point temperature from the General
Eastern 1011B chilled mirror hygrometer. Counts from the core console are
converted to dew point with a polynomial fit, using coefficients provided
in the flight constants paramater CALGE
. The General Eastern
provides a control signal voltage to indicate whether the instrument is
controlling on a due point, and the data are flagged when outside this
range. The valid range is provided through the flight constants parameter
GELIMS
.
Outputs
- TDEW_GE
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TDEW_GE_FLAGcalibration_information
: This instrument cannot be calibratedcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 4instrument_manufacturer
: General Eastern Instrumentsinstrument_model
: 1011B Chilled Mirror Hygrometerinstrument_serial_number
: <str: derived_from_file>long_name
: Dew Point from the General Eastern instrumentstandard_name
: dew_point_temperatureunits
: degK
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
control_data_missing
- No control data is available. The instrument may or may not be controlling on a dew pointcontrol_out_of_range
- The control signal is outside of the specified valid range [7000, 5000]dewpoint_out_of_range
- Dew point outside valid range [195, 394] K
Gin
This module provides variables from the Applanix POS AV 410 GPS-aided inertial navigation system (GIN). The GIN provides parameters at a frequency of 50 Hz; this module simply downsamples these parameters to 32 Hz.
The STATUS_GIN parameter gives the current solution status reported by the GIN. This is defined as
0: Full Nav. (user accuracies met)
1: Fine Align (heading RMS < 15 deg)
2: GC CHI 2 (alignment w/ GPS, RMS heading error > 15 deg)
3: PC CHI 2 (alignment w/o GPS, RMS heading error > 15 deg)
4: GC GHI 1 (alignment w/ GPS, RMS heading error > 45 deg)
5: PC CHI 1 (alignment w/o GPS, RMS heading error > 45 deg)
6: Course levelling active
7: Initial solution assigned
8: No solution
Outputs
- LAT_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: LAT_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Latitude from POS AV 410 GPS-aided Inertial Navigation unitstandard_name
: latitudeunits
: degree_north
- LON_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: LON_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Longitude from POS AV 410 GPS-aided Inertial Navigation unitstandard_name
: longitudeunits
: degree_east
- ALT_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: ALT_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Altitude from POS AV 410 GPS-aided Inertial Navigation unitstandard_name
: altitudeunits
: m
- VELN_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: VELN_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Aircraft velocity north from POS AV 410 GPS-aided Inertial Navigation unitunits
: m s-1
- VELE_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: VELE_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Aircraft velocity east from POS AV 410 GPS-aided Inertial Navigation unitunits
: m s-1
- VELD_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: VELD_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Aircraft velocity down from POS AV 410 GPS-aided Inertial Navigation unitunits
: m s-1
- ROLL_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: ROLL_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Roll angle from POS AV 410 GPS-aided Inertial Navigation unitstandard_name
: platform_roll_angleunits
: degree
- PTCH_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: PTCH_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Pitch angle from POS AV 410 GPS-aided Inertial Navigation unitstandard_name
: platform_pitch_angleunits
: degree
- HDG_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: HDG_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Heading from POS AV 410 GPS-aided Inertial Navigation unitstandard_name
: platform_yaw_angleunits
: degree
- WAND_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: WAND_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Wander angle from POS AV 410 GPS-aided Inertial Navigation unitunits
: degree s-1
- TRCK_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TRCK_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Aircraft track angle from POS AV 410 GPS-aided Inertial Navigation unitstandard_name
: platform_courseunits
: degree
- GSPD_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: GSPD_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Groundspeed from POS AV 410 GPS-aided Inertial Navigation unitstandard_name
: platform_speed_wrt_groundunits
: m s-1
- ROLR_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: ROLR_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Rate-of-change of roll angle from POS AV 410 GPS-aided Inertial Navigation unitstandard_name
: platform_roll_rateunits
: degree s-1
- PITR_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: PITR_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Rate-of-change of pitch angle from POS AV 410 GPS-aided Inertial Navigation unitstandard_name
: platform_pitch_rateunits
: degree s-1
- HDGR_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: HDGR_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Rate-of-change of heading from POS AV 410 GPS-aided Inertial Navigation unitstandard_name
: platform_yaw_rateunits
: degree s-1
- ACLF_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: ACLF_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Acceleration along the aircraft longitudinal axis from POS AV 410 GPS-aided Inertial Navigation unit (positive forward)units
: m s-2
- ACLS_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: ACLS_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Acceleration along the aircraft transverse axis from POS AV 410 GPS-aided Inertial Navigation unit (positive starboard)units
: m s-2
- ACLD_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: ACLD_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Acceleration along the aircraft vertical axis from POS AV 410 GPS-aided Inertial Navigation unit (positive down)units
: m s-2
- STATUS_GIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: STATUS_GIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: Applanixinstrument_model
: POS AV 410long_name
: Solution status from POS AV 410 GPS-aided Inertial Navigation unitunits
: 1
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
no_solution
- The GIN status flag indicates no solution has been obtained.latlon_identically_zero
- Latitude and Longitude are exactly zero. This indicates an erroneous data message.
Heimann
Processing for the Heimann Radiometer. The Heimann outputs a voltage with a
range of 0 - 10 V corresponding to an inferred brightness temperature of
\(-50\) - \(50\) \(^\circ\text{C}\). This module simply applies
a linear transformation to the counts recorded on the DLU to convert counts
\(\rightarrow\) volts \(\rightarrow\) temperature. During a
calibration, temperature from the black body are reported. Parameters for
the linear transformations are taken from the flight constant parameters
HEIMCAL
for the Heimann and PRTCCAL
for the PRT on the black body.
Outputs
- BTHEIM_U
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: BTHEIM_U_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 4instrument_manufacturer
: Heitronicsinstrument_model
: KT19.82instrument_serial_number
: <str: derived_from_file>long_name
: Uncorrected brightness temperature from the Heimann radiometerunits
: K
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
aircraft_on_ground
- The aircraft is on the grounddata_out_of_range
- Brightness temperature is outside the range 253.15 - 313.15 Kin_calibration
- The Heimann is in a calibration cycle. Black body temperature is being reporteddata_missing
- Data are expected but not present
KippZonenPyrgeometer
Calculation of longwave fluxes from the upward and downward facing Kipp and Zonen CR4 Pyrgeometers.
The 0 - 32 mV output of the CR4 thermopile is mapped to a 4 - 20 mA signal in the amp box, which carries sensor specific calibrations, corresponding to a flux range of \(-600\) - \(200\) Wm\(^{-2}\). This is then converted to a voltage using a 350 \(\Omega\) resistor, which is recorded in the DLU, with 16 bits covering a \(-10\) - \(10\) V range. Similarly, the thermistor is placed in parallel with a 100 k\(\Omega\) linearising resistor, and 100 \(\mu\)A is passed through the combination, with the resulting voltage measured at the DLU.
This module first applies the inverse transformations to recover the amp box current and the thermistor resistance. The thermistor temperature is given by
where \(R\) is the thermistor resistance and \(\alpha\), \(\beta\), and \(\gamma\) are calibration coefficients supplied by the manufacturer. The longwave flux, \(L_D\), is then given by
where \(\alpha = 4\), \(\beta=50\), and \(\gamma=600\) map the current from the amp box, \(A\), onto the specified range of flux values, \(T\) is the temperature recorded by the thermistor, and \(\sigma\) is the Stefan-Boltzmann constant.
Outputs
- IR_UP_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: IR_UP_C_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Kipp and Zoneninstrument_model
: CGR 4instrument_serial_number
: <str: derived_from_file>long_name
: Corrected upward longwave irradianceunits
: W m-2
- IR_DN_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: IR_DN_C_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Kipp and Zoneninstrument_model
: CGR 4instrument_serial_number
: <str: derived_from_file>long_name
: Corrected downward longwave irradianceunits
: W m-2
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
aircraft_on_ground
- Aircraft is on the ground
Nephelometer
Provides data and flagging information from the TSI nephelometer. The data from the nephelometer do not require any further processing, however this module parses the instrument status information to provide a QC flag for the data.
Note
Prior to software version 24.0.0, this module used classic flagging. From version 24.0.0, the module uses bitmask flagging, and further flagging may be added by standalone flagging modules.
Outputs
- TSC_BLUU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TSC_BLUU_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: TSIinstrument_model
: 3563long_name
: Uncorrected blue total scattering coefficient from TSI 3563 Nephelometerunits
: m-1
- TSC_GRNU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TSC_GRNU_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: TSIinstrument_model
: 3563long_name
: Uncorrected green total scattering coefficient from TSI 3563 Nephelometerunits
: m-1
- TSC_REDU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TSC_REDU_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: TSIinstrument_model
: 3563long_name
: Uncorrected red total scattering coefficient from TSI 3563 Nephelometerunits
: m-1
- BSC_BLUU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: BSC_BLUU_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: TSIinstrument_model
: 3563long_name
: Uncorrected blue back scattering coefficient from TSI 3563 Nephelometerunits
: m-1
- BSC_GRNU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: BSC_GRNU_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: TSIinstrument_model
: 3563long_name
: Uncorrected green back scattering coefficient from TSI 3563 Nephelometerunits
: m-1
- BSC_REDU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: BSC_REDU_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: TSIinstrument_model
: 3563long_name
: Uncorrected red back scattering coefficient from TSI 3563 Nephelometerunits
: m-1
- NEPH_PR
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NEPH_PR_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: TSIinstrument_model
: 3563long_name
: Internal sample pressure of the Nephelometerunits
: hPa
- NEPH_T
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NEPH_T_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: TSIinstrument_model
: 3563long_name
: Internal sample temperature of the Nephelometerunits
: K
- NEPH_RH
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NEPH_RH_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: TSIinstrument_model
: 3563long_name
: Relative humidity from TSI 3563 Nephelometerunits
: %
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
instrument_flag_raised
- A fault has been raised by the instrument
Nevzorov
Post processing for liquid and total water from the Nevzorov Vane. Works
with both 1T1L2R
and 1T2L1R
vanes, which should be specified in
the flight constants as VANETYPE
.
The Nevzorov hot-wire probe measures total and liquid water content by recording the powers required to hold exposed and sheltered wires at a constant temperature.
The water content, \(W\), measured by a collector is given by
where \(P_c\) is the collector power, \(P_r\) is the reference
power, \(K\) is the baseline, the ratio of \(P_c\) and \(P_r\)
in clear air, \(V_t\) is the true air speed, \(A\) is the
forward-facing area of the collector, and \(L\) is the energy required
to melt and then evaporate the water impacted on the sensor, specified in
the flight constants as CALNVL
.
The baseline, \(K\), is not a true constant, but varies with the ambient conditions. Abel et al. (2014) parameterise \(K\) as a function of indicated air speed, \(V_\text{IAS}\) and ambient pressure, \(P\),
If, for any reason, the fitting above fails, then only the uncorrected outputs, using a constant \(K\) specified in the flight constants, are written to file.
The outputs listed produced by this module depend on the type of Nevzorov
vane fitted to the aircraft. If an old-style 1T1L2R
vane is fitted,
then the default outputs are
NV_TWC_C, NV_LWC_C, NV_TWC_COL_P, NV_LWC_COL_P, NV_TWC_REF_P, NV_LWC_REF_P.
If a new-style 1T2L1R
vane is fitted, then the default outputs are
NV_TWC_C, NV_LWC1_C, NV_LWC2_C, NV_TWC_COL_P, NV_LWC1_COL_P,
NV_LWC2_COL_P, NV_REF_P.
Note
Prior to software version 24.6.0 this module output uncorrected water content data (NV_TWC_U, NV_LWC_U, NV_LWC1_U, NV_LWC2_U), instead of the element powers. These outputs are no longer produced.
Outputs
- NV_TWC_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NV_TWC_C_FLAGcomment
: Automatically baselined using flight data.coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 64instrument_manufacturer
: Sky Phys Tech Inc.instrument_model
: <str: derived_from_file>instrument_serial_number
: <str: derived_from_file>long_name
: Corrected total condensed water content from the Nevzorov probeunits
: gram m-3
- NV_TWC_COL_P
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NV_TWC_COL_P_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 64instrument_manufacturer
: Sky Phys Tech Inc.instrument_model
: <str: derived_from_file>instrument_serial_number
: <str: derived_from_file>long_name
: TWC collector powerunits
: W
- NV_TWC_REF_P
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NV_TWC_REF_P_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 64instrument_manufacturer
: Sky Phys Tech Inc.instrument_model
: <str: derived_from_file>instrument_serial_number
: <str: derived_from_file>long_name
: TWC reference powerunits
: W
- NV_REF_P
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NV_REF_P_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 64instrument_manufacturer
: Sky Phys Tech Inc.instrument_model
: <str: derived_from_file>instrument_serial_number
: <str: derived_from_file>long_name
: Reference powerunits
: W
- NV_LWC_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NV_LWC_C_FLAGcomment
: Automatically baselined using flight data.coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 64instrument_manufacturer
: Sky Phys Tech Inc.instrument_model
: <str: derived_from_file>instrument_serial_number
: <str: derived_from_file>long_name
: Corrected liquid water content from the Nevzorov probestandard_name
: mass_concentration_of_liquid_water_in_airunits
: gram m-3
- NV_LWC_COL_P
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NV_LWC_COL_P_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 64instrument_manufacturer
: Sky Phys Tech Inc.instrument_model
: <str: derived_from_file>instrument_serial_number
: <str: derived_from_file>long_name
: LWC collector powerunits
: W
- NV_LWC_REF_P
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NV_LWC_REF_P_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 64instrument_manufacturer
: Sky Phys Tech Inc.instrument_model
: <str: derived_from_file>instrument_serial_number
: <str: derived_from_file>long_name
: LWC reference powerunits
: W
- NV_LWC1_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NV_LWC1_C_FLAGcomment
: Automatically baselined using flight data.coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 64instrument_manufacturer
: Sky Phys Tech Inc.instrument_model
: <str: derived_from_file>instrument_serial_number
: <str: derived_from_file>long_name
: Corrected liquid water content from the Nevzorov probe (1st collector)standard_name
: mass_concentration_of_liquid_water_in_airunits
: gram m-3
- NV_LWC1_COL_P
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NV_LWC1_COL_P_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 64instrument_manufacturer
: Sky Phys Tech Inc.instrument_model
: <str: derived_from_file>instrument_serial_number
: <str: derived_from_file>long_name
: LWC1 collector powerunits
: W
- NV_LWC2_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NV_LWC2_C_FLAGcomment
: Automatically baselined using flight data.coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 64instrument_manufacturer
: Sky Phys Tech Inc.instrument_model
: <str: derived_from_file>instrument_serial_number
: <str: derived_from_file>long_name
: Corrected liquid water content from the Nevzorov probe (2nd collector)standard_name
: mass_concentration_of_liquid_water_in_airunits
: gram m-3
- NV_LWC2_COL_P
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NV_LWC2_COL_P_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 64instrument_manufacturer
: Sky Phys Tech Inc.instrument_model
: <str: derived_from_file>instrument_serial_number
: <str: derived_from_file>long_name
: LWC2 collector powerunits
: W
- NV_CLEAR_AIR_MASK
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: NV_CLEAR_AIR_MASK_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 64instrument_manufacturer
: Sky Phys Tech Inc.instrument_model
: <str: derived_from_file>instrument_serial_number
: <str: derived_from_file>long_name
: Clear air mask based on Nevzorov Total Water power varianceunits
: None
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
aircraft_on_ground
- The aircraft is on the groundpoor_clear_air_baseline
- The Nevzorov baseline correction is poor in clear air (|dk| > 0.02)
PRTTemperatureUncertainties
For further details see the FAAM Met. Handbook.
This module calculates combined uncertainty estimates for indicated and true air temperatures, when these are recorded with platinum resistance thermometers.
Uncertainties in the indicated temperatures are derived from:
Uncertainty in the thermometer calibration from NPL
Drift of sensors between NPL calibrations
Resolution uncertainty in the DECADES DLU
DECADES calibration uncertainty
Noise in the system when a fixed resistor is fitted
Keithley calibration
Keithley stability
DECADES calibration (counts to resistance) residual
NPL calibration (resistance to temperature) residual.
Uncertainties in the true air temperatures are derived from:
Uncertainty of the corresponding indicated air temperature
Uncertainty in the Mach number
Uncertainty in the ratio of specific heats
Uncertainty in the variable housing recovery factor.
Outputs
- IAT_ND_R_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: IAT_ND_R_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 32long_name
: Combined uncertainty estimate for IAT_ND_Runits
: K
- TAT_ND_R_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TAT_ND_R_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 32long_name
: Combined uncertainty estimate for TAT_ND_Runits
: K
- IAT_DI_R_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: IAT_DI_R_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 32long_name
: Combined uncertainty estimate for IAT_DI_Runits
: K
- TAT_DI_R_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TAT_DI_R_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 32long_name
: Combined uncertainty estimate for TAT_DI_Runits
: K
Flags
PRTTemperatures
For further details see the FAAM Met. Handbook.
Calculate indicated and true (static) air temperatures from the deiced and
non-deiced Rosemount housings, when fitted with platinum resistance
thermometer sensors. Indicated temperatures are calculated with a
polynomial transformation of the DLU signal, using calibration factors in
constants variables CALDIT
and CALNDT
, which incorporates
the DLU and sensor calibrations.
The deiced indicated temperature is subject to a heating correction term when the heater is active, given by
where \(M\) is the Mach number, \(q\) is the dynamic pressure and \(P\) the static pressure. The parameters \(a\), \(b\), \(c\), and \(s\) are
True air temperatures are a function of indicated temperatures, Mach number and housing recovery factor, and are given by
where \(M\) is the Mach number and \(R_f\) the recovery factor. Recovery factors are calculated in the processing module RecoveryFactor.
A flag is applied to the data when the Mach number is out of range. Further flags may be added by standalone flagging modules.
Outputs
- TAT_ND_R
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TAT_ND_R_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>comment
: Sensor housed in Rosemount Aerospace Inc. Type 102 non-deiced Total Temperature Housingcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: True air temperature from the Rosemount non-deiced temperature sensorsensor_serial_number
: <str: derived_from_file>sensor_type
: <str: derived_from_file>standard_name
: air_temperatureunits
: K
- TAT_DI_R
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TAT_DI_R_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>comment
: Sensor housed in Rosemount Aerospace Inc. Type 102 deiced Total Temperature Housingcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: True air temperature from the Rosemount deiced temperature sensorsensor_serial_number
: <str: derived_from_file>sensor_type
: <str: derived_from_file>standard_name
: air_temperatureunits
: K
- IAT_ND_R
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: IAT_ND_R_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>comment
: Sensor housed in Rosemount Aerospace Inc. Type 102 non-deiced Total Temperature Housingcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Indicated air temperature from the Rosemount non-deiced temperature sensorsensor_serial_number
: <str: derived_from_file>sensor_type
: <str: derived_from_file>units
: K
- IAT_DI_R
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: IAT_DI_R_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>comment
: Sensor housed in Rosemount Aerospace Inc. Type 102 deiced Total Temperature Housingcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Indicated air temperature from the Rosemount deiced temperature sensorsensor_serial_number
: <str: derived_from_file>sensor_type
: <str: derived_from_file>units
: K
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
mach_out_of_range
- Mach number is below acceptable minimum of 0.05
PSAP
Reports data from the Radiance Research Particle Soot Absorbtion Photometer. The following transformations are applied to the data from the aerosol rack DLU:
where \(P_\text{lin}\), \(P_\text{log}\), \(F\), and \(T\)
correspond to the outputs PSAP_LIN
, PSAP_LOG
, PSAP_FLO
, and
PSAP_TRA
respectively.
Flagging is based on the flow rate and transmittance ratio limits.
Outputs
- PSAP_FLO
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: PSAP_FLO_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Radiance Researchlong_name
: PSAP Flowunits
: l min-1
- PSAP_LIN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: PSAP_LIN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Radiance Researchlong_name
: Uncorrected absorbtion coefficient at 565nm, linear, from PSAPunits
: m-1
- PSAP_LOG
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: PSAP_LOG_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Radiance Researchlong_name
: Uncorrected absorption coefficient at 565nm, log, from PSAPunits
: 1
- PSAP_TRA
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: PSAP_TRA_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Radiance Researchlong_name
: PSAP Transmittanceunits
: percent
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
transmittance_out_of_range
- Transmittance ratio is outside the valid range [0.5, 1.05flow_out_of_range
- PSAP flow is out of range. This most likely indicates that the PSAP interrupt is active, to prevent water ingress
RadAlt
Calculate the radar altitude, in metres. The radar altitude, from radalt2, is read from the aircraft ARINC-429 data bus at the rear core console, and recodred at a frequency of 2 Hz. The signal is received as a 16 bit signed integer, with a least significant bit resolution of 0.25 ft, giving a max valid value of \((((2^{16} / 2) - 1) / 4)\).
Data are flagged when below 10 feet or above 5000 feet, which is the nominal maximum range of the instrument, though altitude is reported up to 8000 ft.
Outputs
- HGT_RADR
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: HGT_RADR_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 2instrument_manufacturer
: Thalesinstrument_model
: AVH16 Radar Altimeterlong_name
: Radar height from the aircraft radar altimeterstandard_name
: heightunits
: m
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
data_out_of_range
- RadAlt reading outside valid range (10.00, 1524.00)aircraft_on_ground
- The aircraft is on the ground, as indicated by the weight on wheels flag.
RecoveryFactor
For further details see the FAAM Met. Handbook.
This module produces a Mach dependent recovery factor for the deiced and non-deiced Rosemount housings, which house the temperature probes.
The recovery factor for the non-deiced housing is given by Rosemount Aerospace as
where \(a_1 = 0.0014054157\) and \(a_2 = -0.00060943146\)
The recovery factor for the deiced housing is calculated from in-flight data, under the assumption that the recovery factor given by Rosemount is correct. It is given by
where \(\alpha = 0.9989\) is the average ratio of deiced and non-deiced indicated temperatures. Further information is available in the FAAM Recovery Factor report (H. Price, document # FAAM013006).
Uncertainties are given by
Outputs
- ETA_ND
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Variable recovery factor for non-deiced Rosemount housingunits
: 1
- ETA_DI
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Variable recovery factor for deiced Rosemount housingunits
: 1
- ETA_ND_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: ETA_ND_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 32long_name
: Uncertainty in recovery factor for deiced Rosemount housingunits
: 1
- ETA_DI_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: ETA_DI_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 32long_name
: Uncertainty in recovery factor for non-deiced Rosemount housingunits
: 1
Flags
Rvsm
Calculate derived parameters from the aircraft’s RVSM system. Pressure altitude and indicated air speed are obtained from the aircraft’s ARINC-429 data bus, with a least significant bit resolution of 4 ft and \(1/32\) kts respectively.
Static pressure, \(P\), is obtained from the pressure altitude, \(Z_p\), using the ICAO standard atmosphere,
where \(T_0=288.15\), \(L_0=-0.0065\), \(h_0=0\), \(g_0=9.80655\), \(M=0.0289644\), \(R=8.31432\), \(P_0=1013.25\) below 11000 m, or
where \(T_1=216.65\), \(P_1=226.321\), \(h_1=11000\), above 11000 m.
Pitot static pressure, \(q\), is given as
with the Mach number, \(M\), given by
where \(V_0 = 340.294\) and \(P_0=1013.25\), and \(V_{IAS}\) is the indicated air speed.
Data are flagged where either the pressure altitude or indicated air speed are considered out of range.
Outputs
- PS_RVSM
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: PS_RVSM_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: BAE Systemslong_name
: Static pressure from the aircraft RVSM (air data) systemstandard_name
: air_pressureunits
: hPa
- PALT_RVS
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: PALT_RVS_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: BAE Systemslong_name
: Pressure altitude from the aircraft RVSM (air data) systemstandard_name
: barometric_altitudeunits
: m
- Q_RVSM
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: Q_RVSM_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32instrument_manufacturer
: BAE Systemslong_name
: Pitot static pressure inverted from RVSM (air data) system indicated airspeedunits
: hPa
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
instrument_not_ready
- The RVSM system may not be ready for usealtitude_out_of_range
- Pressure altitude outside acceptable range [-2000, 50000]ias_out_of_range
- Indicated air speed outside acceptable range [-50, 500]
S10Pressure
Calculate static pressure from the S10 fuselage ports. Static pressure is
calulated by applying a polynomial transformation to the DLU signal. The
coefficients, specified in the flight constants parameter CALS10SP
,
combine both the DLU and pressure transducer calibrations.
Data are flagged when they are considered out of range.
Outputs
- P10_STAT
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: P10_STAT_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Static pressure from S10 fuselage portssensor_manufacturer
: Rosemount Aerospace Inc.sensor_model
: 1201F2sensor_serial_number
: <str: derived_from_file>standard_name
: air_pressureunits
: hPa
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
data_out_of_range
- Pressure outside acceptable limits [100, 1050]
S9Pressure
Calculate static pressure from the S9 fuselage ports. Static pressure is
calulated by applying a polynomial transformation to the DLU signal. The
coefficients, specified in the flight constants parameter CALS9SP
,
combine both the DLU and pressure transducer calibrations. Additionally, a
Mach dependent ‘position error’ correction term is applied, aimed at
accounting for the unknown position error associated with the S9 port,
derived by minimising errors between the S9 and RVSM static pressure
measurements. This correction is of the form
with parameters \(\alpha\) and \(\beta\) specified in the flight
constants parameter S9_PE_C
.
Data are flagged when they are considered out of range.
Outputs
- P9_STAT
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: P9_STAT_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Static pressure from S9 fuselage portssensor_manufacturer
: Rosemount Aerospace Inc.sensor_model
: 1201F2sensor_serial_number
: <str: derived_from_file>standard_name
: air_pressureunits
: hPa
- P9_STAT_U
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: P9_STAT_U_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Static pressure from S9 fuselage ports, uncorrectedsensor_manufacturer
: Rosemount Aerospace Inc.sensor_model
: 1201F2sensor_serial_number
: <str: derived_from_file>standard_name
: air_pressureunits
: hPa
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
data_out_of_range
- Pressure outside acceptable limits [100, 1050]
SeaProbe
Calculates bulk water contents from the SEA WCM-2000 sensor.
Element Power
First element powers \(P = V*I\) are derived from recorded voltages and currents for each element (TWC, 083, 021, CMP, DCE).
Cloud mask
A cloud mask is derived using a rolling window applied to the TWC element temperature, with the aircraft assumed to be in cloud whenever the temperature range within the rolling window exceeds a specified range, or where the temperature withing the window exceeds a specified high or low value.
Parameters
Temperature of evaporation, \(T_{\text{evap}}\), and latent heat of evaporation, \(L_{\text{evap}}\), are given by
where \(P\) is the static pressure from the aircraft’s air data system.
The specific energies for evaporation and sublimination, \(L_\text{liq}\) and \(L_\text{ice}\), are given by
where \(T_a\) is the ambient air temperature, and
and
where \(L_\text{ice} = 333.5\), and \(C_\text{ice}\) is given by an interpolant between \(T = [77, 173, 273]\) and \(C = [0.686, 1.372, 2.097]\).
Dry air term
The dry air compensation term is calculated in two methods, with the method which gives the best fit meing used
Method 1: Calculate dry air power term by fitting constants for 1st principles.
The calculation of the dry air power term is based on method three as described on page 58 of the WCM-2000 manual. This uses a fit between the theoretical and measured (in cloud-free conditions) sense powers to find the fitting constants \(k_1\) and \(k_2\) (\(k_2\approx0.5\)).
Method 2: Calculate dry air power term from compensation element measurements.
The calculation of the dry air power term (DAT) is based on the use of the compensation element as described on page 56 of the WCM-2000 manual. This finds the slope and offset for conversion of the compensation power to dry air sense element power.
This will be TAS and \(P\) dependent (possibly \(T_a\)). This function determines optimum fitting parameters for the entire dataset, thus any baseline drift shall be lost.
Sense element water content
The water content for an element is given by
where \(P_\text{sense}\) is the (wet) sense element power, and \(w\) and \(h\) are the width and height of the sense element, respectively.
Note
The flags on upstream variables TAT_DI_R
and TAS_RVSM
are not included in
the dependency_is_flagged
flag of this variable, as these are likely to be
flagged whenever the aircraft is in cloud.
Outputs
- SEA_TWC_021
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SEA_TWC_021_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 20instrument_manufacturer
: Science Engineering Associates, Inc.instrument_model
: WCM-2000instrument_serial_number
: <str: derived_from_file>long_name
: Total water content from the SEA WCM-2000 probe, element 021units
: g m-3
- SEA_TWC_083
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SEA_TWC_083_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 20instrument_manufacturer
: Science Engineering Associates, Inc.instrument_model
: WCM-2000instrument_serial_number
: <str: derived_from_file>long_name
: Total water content from the SEA WCM-2000 probe, element 083units
: g m-3
- SEA_LWC_021
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SEA_LWC_021_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 20instrument_manufacturer
: Science Engineering Associates, Inc.instrument_model
: WCM-2000instrument_serial_number
: <str: derived_from_file>long_name
: Liquid water content from the SEA WCM-2000 probe, element 021standard_name
: mass_concentration_of_liquid_water_in_airunits
: g m-3
- SEA_LWC_083
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SEA_LWC_083_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 20instrument_manufacturer
: Science Engineering Associates, Inc.instrument_model
: WCM-2000instrument_serial_number
: <str: derived_from_file>long_name
: Liquid water content from the SEA WCM-2000 probe, element 083standard_name
: mass_concentration_of_liquid_water_in_airunits
: g m-3
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
element_temperature_out_of_range
- No flag description provided.aircraft_on_ground
- No flag description provided.
SignalRegister
The DECADES signal register is a packed representation of some boolean state variables, which is used internally in DECADES. Here we reproduce part of the register from flag variables reported in the TCP data, for use in other processing modules. No outputs defined here are expected to ever be written to file.
Outputs
- SREG
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SREG_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 2long_name
: Signal Registerunits
: None
Flags
Variables in this module use classic, value based flagging.
- SREG_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
SolarAngles
Calculates solar azimuth and zenith angles at the aircraft location. Uses
the third party python module pysolar
.
Outputs
- SOL_ZEN
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SOL_ZEN_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: Solar zenith derived from aircraft position and timestandard_name
: solar_zenith_angleunits
: degree
- SOL_AZIM
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SOL_AZIM_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: Solar azimuth derived from aircraft position and timestandard_name
: solar_azimuth_angleunits
: degree
Flags
Variables in this module use classic, value based flagging.
- SOL_ZEN_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
- SOL_AZIM_FLAG
-128
:data_not_flagged
- A fill value. No flagging information has been provided
TPress
This module calculates turbulence probe pressure differentials between P0-S10, left-right, and up-down.
The raw inputs are DLU counts from the differential pressure transducers.
Pressures are calculated with polynomial fits to the raw counts, which
encompass both the pressure to volts calibration of the transducer, and the
volts to counts calibration of the DLU. These are given in the constant
parameters CALTP1
, CALTP2
, and CALTP3
, for P0-S10, up-down, and
left right, respectively.
Data are flagged when outside specified limits.
Outputs
- P0_S10
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: P0_S10_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Calibrated differential pressure between centre (P0) port and S10 staticsensor_manufacturer
: Rosemount Aerospace. Inc.sensor_model
: 1221F2sensor_serial_number
: <str: derived_from_file>units
: hPa
- PA_TURB
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: PA_TURB_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Calibrated differential pressure between turbulence probe vertical portssensor_manufacturer
: Rosemount Aerospace. Inc.sensor_model
: 1221F2sensor_serial_number
: <str: derived_from_file>units
: hPa
- PB_TURB
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: PB_TURB_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Calibrated differential pressure between turbulence probe horizontal portssensor_manufacturer
: Rosemount Aerospace. Inc.sensor_model
: 1221F2sensor_serial_number
: <str: derived_from_file>units
: hPa
Flags
Variables in this module use classic, value based flagging.
- P0_S10_FLAG
0
:data_good
- None1
:data_out_of_range
- None
- PA_TURB_FLAG
0
:data_good
- None1
:data_out_of_range
- None
- PB_TURB_FLAG
0
:data_good
- None1
:data_out_of_range
- None
TecoSO2
Warning
This module depreciated for flights after 2021-01-09
Calculate SO\(_2\) concentration from the TECO 43 instrument. The instrument reports a nominal concentration and sensitivity, valve states V6 (indicating cylinder air) and V8 (indicating cabin air), and a status flag.
Zeros are taken whenever the instrument in sampling cylinder or cabin air, and interploated back to 1 Hz, assuming a linear drift of the offsets between zeros. SO\(_2\) concentration is then given by
where \(\left[\text{SO}_{2|\text{INS}}\right]\) is the concentration reported by the instrument, \(Z\) is the zero obtained from sampling cylinder or cabin air, and \(S\) is the sensitivity reported by the instrument.
Flagging is based on valve states and the instrument status flag.
Outputs
- SO2_TECO
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SO2_TECO_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Thermo Fisher Scientific, Inc.instrument_model
: 43i TLE pulsed fluorescence SO2 spectrometerlong_name
: Mole fraction of Sulphur Dioxide in air from TECO 43 instrumentstandard_name
: mole_fraction_of_sulfur_dioxide_in_airunits
: ppb
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
aircraft_on_ground
- Aircraft is on the groundbefore_first_zero
- The instrument has not yet sampled cylinder or cabin air, the zero is invalidin_zero
- The instrument is currently sampling cylinder or cabin air for a zero readingin_alarm
- The instrument status flag is currently indicating an alarm state
TecoSO2V2
Note
This module only active for flights after 2021-01-09
Calculate SO\(_2\) concentration from the TECO 43 instrument.
Zeros are taken whenever valve states V7 or V8 are 1, and are interpolated back to 1 Hz, assuming a linear drift of the offsets between zeros. SO\(_2\) concentration is then given by
where \(\left[\text{SO}_{2|\text{INS}}\right]\) is the concentration reported by the instrument, \(Z\) is the zero obtained from sampling scrubbed ambient air, and \(S\) is the instrument sensitivity given in the flight constants.
Flagging is based on valve states, weight on wheels, and the instrument status flag.
Outputs
- SO2_TECO
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SO2_TECO_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Thermo Fisher Scientific, Inc.instrument_model
: 43i Trace Level-Enhanced pulsed fluorescence SO2 spectrometerinstrument_serial_number
: 1505564557long_name
: Mole fraction of Sulphur Dioxide in air from TECO 43 instrumentstandard_name
: mole_fraction_of_sulfur_dioxide_in_airunits
: ppb
- SO2_TECO_ZERO
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]calibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Thermo Fisher Scientific, Inc.instrument_model
: 43i Trace Level-Enhanced pulsed fluorescence SO2 spectrometerinstrument_serial_number
: 1505564557long_name
: TECO 43 SO2 interpolated zerounits
: ppb
Flags
TeiOzone
Provides ozone concentration from the TE49C O\(_3\) analyser. Ozone data are taken as-is from the instrument; this module provides flagging information based on threshold values and instrument status flags.
Outputs
- O3_TECO
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: O3_TECO_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: Thermo Fisher Scientific, Inc.instrument_model
: 49i IV absorption ozone photometerlong_name
: Mole fraction of Ozone in air from the TECO 49 instrumentstandard_name
: mole_fraction_of_ozone_in_airunits
: ppb
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
instrument_alarm
- The status flag provided by the instrument is indicating an alarm stateconc_out_of_range
- Reported ozone concentration is below the valid minimum of -10flow_out_of_range
- At least one of the recorded flow rates is below the valid minimum of 0.5aircraft_on_ground
- The aircraft is on the ground
ThermistorV1Temperatures
Calculate indicated and true (static) air temperatures from the Rosemount temperature probes, for the V1 (prototype) thermistor circuit. Note that when using this circuit, only one of the housings may host a thermistor type sensor.
Processes the NPL calibrations to produce a resistance to probe temperature relationship. The NPL calibration is performed with two different applied voltages so that self-heating can be calculated. This allows the probe temperature to be inferred by adding the calibration chamber temperature to the self-heating in order to produce a useable probe temperature to resistance calibration.}
Processes the NPL calibrations for a temperature to dissipation constant relationship. The dissipation constant measured in the calibration chamber for a given temperature is used later in the removal of self-heating in flight.}
Calculates the indicated temperature of the thermistor sensor by applying the NPL calibration and the DECADES counts to voltage calibration.
Calculates the dissipation constant at that indicated temperature based on the calibration dissipation constant and the flight dissipation multiplier (as described in FAAM013004A).}
Calculates the in-flight self-heating for each measurement, based on the voltage measurements and in-flight dissipation constants.}
Produces an indicated temperature corrected for self-heating by subtracting the self-heating from the temperature of the sensor.}
The deiced indicated temperature is subject to a heating correction term when the heater is active, given by
where \(M\) is the Mach number, \(q\) is the dynamic pressure and \(P\) the static pressure. The parameters \(a\), \(b\), \(c\), and \(d\) are
True air temperatures are a function of indicated temperatures, Mach number and housing recovery factor, and are given by
where \(M\) is the Mach number and \(R_f\) the recovery factor.
Recovery factors are currently considered constant, and are specified in the
flight constants parameters RM_RECFAC/DI
and RM\_RECFAC/ND
.
A flag is applied to the data when the Mach number is out of range. Further flags may be added by standalone flagging modules.
Outputs
- IAT_ND_R
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: IAT_ND_R_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>comment
: Sensor housed in Rosemount Aerospace Inc. Type 102 non-deiced Total Temperature Housingcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Indicated air temperature from the Rosemount non-deiced temperature sensorsensor_serial_number
: <str: derived_from_file>sensor_type
: thermistorunits
: K
- TAT_ND_R
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TAT_ND_R_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>comment
: Sensor housed in Rosemount Aerospace Inc. Type 102 non-deiced Total Temperature Housingcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: True air temperature from the Rosemount non-deiced temperature sensorsensor_serial_number
: <str: derived_from_file>sensor_type
: thermistorstandard_name
: air_temperatureunits
: K
- IAT_DI_R
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: IAT_DI_R_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>comment
: Sensor housed in Rosemount Aerospace Inc. Type 102 deiced Total Temperature Housingcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Indicated air temperature from the Rosemount deiced temperature sensorsensor_serial_number
: <str: derived_from_file>sensor_type
: thermistorunits
: K
- TAT_DI_R
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TAT_DI_R_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>comment
: Sensor housed in Rosemount Aerospace Inc. Type 102 deiced Total Temperature Housingcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: True air temperature from the Rosemount deiced temperature sensorsensor_serial_number
: <str: derived_from_file>sensor_type
: thermistorstandard_name
: air_temperatureunits
: K
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
mach_out_of_range
- No flag description provided.
TurbulenceProbe
This module produces flow angles and airspeed from the turbulence probe pressure differentials, and combines these with inertial/GPS measurements to derive 3-dimensional winds. These two processes are performed iteratively so that covariances between inferred winds and inertial measurements can be used to calculate on-the-fly flow angle correction terms. Alternatively, flow angle corrections can be provided in the flight constants.
Flow angles, dynamic pressure, and TAS
Initial estimates for angle of attack, \(\alpha\), and angle of sideslip, \(\beta\), are given by
Here, \(P_a\) and \(P_b\) are the pressure differentials between the top/bottom and left/right probe ports, \(a_n\) and \(b_n\) are calibration coefficients derived from flight data, and \(q\) is the RVSM-derived dynamic pressure.
Correction terms to these flow angles, required as stagnation points do not correspond exactly with probe ports, calculated by BAeS during the probe commissioning, are given by
An initial estimate of dynamic pressure from the turbulence probe, \(q_t\), is then given by
where \(\Delta_{P_0S_{10}}\) is the pressure differential between \(P_0\) and \(S_{10}\).
This whole process is then iteratively repeated with \(q = q_t\), either until the difference in both flow angles between iterations is less than 0.2 degrees, or 5 iterations have been completed.
Mach number, \(M\), is given by
where \(p\) is the static pressure from the RVSM system.
True airspeed, TAS, is then given by
where \(\text{TAS}_c\) is a correction term derived from flight data, \(C_0\) is the speed of sound at ICAO STP, \(T_\text{air}\) is the (deiced) true air temperature, and \(T_0\) is the temperature at ICAO STP.
Wind vector
First let us define rotation matricies which provide the transformations between geographical and aircraft-relative coordinate systems.
where \(r\), \(\theta\), and \(\phi\) are the aircraft roll, pitch, and yaw, respectively. We can combine these into a single transformation tensor, \(\mathbf{R} = (\mathbf{A_3}\cdot\mathbf{A_2}) \cdot\mathbf{A_1}\).
The wind vector \(\mathbf{U}\), is given by
where \(\mathbf{V}\) is the aircraft velocity vector, \(\mathbf{T}\) is the aircraft TAS vector, relative to the earth, and \(\mathbf{L}\) is a correction term which accounts for the offset between the aircraft inertial measurement and the turbulence probe.
The correction term \(\mathbf{L}\) is given by
where \(\mathbf{L_R} = \mathbf{R} \cdot \mathbf{l}\) and \(\mathbf{L_L} = \mathbf{L_1} + \mathbf{L_2} + \mathbf{L_3}\).
Here \(\mathbf{l}\) is the position vector describing the offset of the inertial measurement from the turbulence probe, and
where an overdot represents a time derivative.
The TAS term \(\mathbf{T}\) is given by
where
Flow angle corrections
The derivation of the variables above assumes no flow angle corrections, which are generally required. We take the approach of calculating flow angle corrections on line. This is done in an iterative loop where, after calculation of the flow angles and wind vector, flow angle corrections are calulated by 1) minimising the covariance between platform roll and vertical wind in the turns, and 2) minimising the mean vertical wind when the platform is straight and level. Flow angles and are then recalculated, and so on until the flow angle corrections converge suitably. This has been seen to occur rapidly, and only two iterations after the initial calculations are performed.
Outputs
- TAS
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: TAS_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: True airspeed (dry-air) from turbulence probestandard_name
: platform_speed_wrt_airunits
: m s-1
- AOA
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: AOA_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Angle of attack from the turbulence probe (positive, flow upwards wrt a/c axes)units
: degree
- AOSS
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: AOSS_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Angle of sideslip from the turbulence probe (positive, flow from left)units
: degree
- PSP_TURB
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: PSP_TURB_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Pitot-static pressure from centre-port measurements corrrected for AoA and AoSSunits
: hPa
- U_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: U_C_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Eastward wind component from turbulence probe and GINstandard_name
: eastward_windunits
: m s-1
- V_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: V_C_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Northward wind component from turbulence probe and GINstandard_name
: northward_windunits
: m s-1
- W_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: W_C_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Vertical wind component from turbulence probe and GINstandard_name
: upward_air_velocityunits
: m s-1
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
data_out_of_range
- V_C is outside the specified valid range [(-60, 60)] m/saircraft_on_ground
- aircraft on groundmach_out_of_range
- Mach # is outside the specified valid range [(0.05, 0.8)]
TwoBOzone
Note
This module only active for flights after 2021-01-09
Provides ozone concentration from the 2B Tech Ozone instrument. The instrument natively provides an ozone concentration, however this may be zero adjusted and scaled by zero and senstivity parameters given in the flight constants as TWBOZO_ZERO and TWBOZO_SENS.
where \(z\) is the given zero offset and \(S\) is the given sensitivity.
Additional calibration information for metadata can be provided through the constant parameters TWBOZO_CALINFO_DATE, TWBOZO_CALINFO_INFO, and TWBOZO_CALINFO_URL.
Flagging information is provided based on instrument and aircraft status.
Outputs
- O3_2BTECH
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: O3_2BTECH_FLAGcalibration_date
: <str: derived_from_file optional>calibration_information
: <str: derived_from_file optional>calibration_url
: <str: derived_from_file optional>coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_description
: <str: derived_from_file optional>instrument_manufacturer
: 2B Technologies Inc.instrument_model
: 205instrument_serial_number
: 1034DBlong_name
: Mole fraction of Ozone in air from the 2BTech photometerstandard_name
: mole_fraction_of_ozone_in_airunits
: ppb
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
aircraft_on_ground
- The aircraft is on the ground, as indicated by the weight on wheels flag. An additional 10 seconds are addedafter take-off to allow for instrument flushing.inlet_flow_out_of_range
- The inlet sample overflow is out of range.sample_flow_out_of_range
- The spectrometer sample mass flow rate is out of range.
WVSS2A
Process data from the WVSS-II water vapour spectrometers. The WVSS2 report volume mixing ratio and other parameters approximately every 2.3 seconds. This represents ~2 s of sampling at ~4 Hz, followed by around 0.3 seconds of processing. This module simply linearly interpolates these data onto a regular 1 Hz index, and provides flagging and metadata.
Outputs
- WVSS2F_VMR_U
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: WVSS2F_VMR_U_FLAGcomment
: WVSS-II measurements rely on manufacturer calibrations, and are not tracable to national standardscoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: SpectraSensorslong_name
: Water Vapour Measurement from WVSS2F linearly interpolated to 1 Hzunits
: ppmv
- WVSS2F_PRESS_U
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: WVSS2F_PRESS_U_FLAGcomment
: WVSS-II measurements rely on manufacturer calibrations, and are not tracable to national standardscoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: SpectraSensorslong_name
: Pressure inside WVSS2F sample cell linearly interpolated to 1 Hzunits
: hPa
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
data_out_of_range
- No flag description provided.data_missing
- No flag description provided.aircraft_on_ground
- No flag description provided.
WVSS2B
Process data from the WVSS-II water vapour spectrometers. The WVSS2 report volume mixing ratio and other parameters approximately every 2.3 seconds. This represents ~2 s of sampling at ~4 Hz, followed by around 0.3 seconds of processing. This module simply linearly interpolates these data onto a regular 1 Hz index, and provides flagging and metadata.
Outputs
- WVSS2R_VMR_U
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: WVSS2R_VMR_U_FLAGcomment
: WVSS-II measurements rely on manufacturer calibrations, and are not tracable to national standardscoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: SpectraSensorslong_name
: Water Vapour Measurement from WVSS2R linearly interpolated to 1 Hzunits
: ppmv
- WVSS2R_PRESS_U
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: WVSS2R_PRESS_U_FLAGcomment
: WVSS-II measurements rely on manufacturer calibrations, and are not tracable to national standardscoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: SpectraSensorslong_name
: Pressure inside WVSS2R sample cell linearly interpolated to 1 Hzunits
: hPa
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
data_out_of_range
- No flag description provided.data_missing
- No flag description provided.aircraft_on_ground
- No flag description provided.
WVSS2Calibrated
For further details see the FAAM Met. Handbook.
This module provides a calibrated WVSS2 volume mixing ratio, along with its
uncertainty estimate, from the flush mounted instrument. The calibration is
a polynomial in VMR, with coefficients provided in the constants parameter
WVSS2_F_CAL
. The calibration is assumed to only be valid within a
certain VMR range, specified in the constants parameter
WVSS2_F_CAL_RANGE
. Outside of this range, data are set to NaN.
The uncertainty estimate, \(U_c\), is given by
where
where \(V\) is the uncorrected volume mixing ratio, \(\sigma_0,
..., \sigma_n\) are specified in the constants parameter
WVSS2_F_UNC_FITPARAMS
, \(l_0 \text{ and} l_1\) are specified in the
constants parameter WVSS2_F_UNC_BUCK
and \(p_0 \text{ and} p_1\)
are specified in the constants parameter WVSS2_F_UNC_FITRES
.
Outputs
- WVSS2F_VMR_C
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: WVSS2F_VMR_C_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1instrument_manufacturer
: SpectraSensorsinstrument_serial_number
: <str: derived_from_file>long_name
: Calibrated volume mixing ratio from WVSS2Funits
: ppm
- WVSS2F_VMR_C_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: WVSS2F_VMR_C_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 1instrument_manufacturer
: SpectraSensorsinstrument_serial_number
: <str: derived_from_file>long_name
: Uncertainty estimate for calibrated volume mixing ratio from WVSS2Funits
: ppm
Flags
WVSS2RH
This module provides estimates of relative humidity with respect to both water and ice, along with their combined uncertainty estimates, derived from the WVSS2 water vapour mixing ratio and Rosemount temperatures.
For full details of the methodology, see the FAAM Met. Handbook.
Outputs
- RH_ICE
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: RH_ICE_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: Relative humidity wrt ice water, derived from corrected WVSS-II VMR and Rosemount temperaturesstandard_name
: relative_humidityunits
: %
- RH_LIQ
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: RH_LIQ_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: Relative humidity wrt liquid water, derived from corrected WVSS-II VMR and Rosemount temperaturesstandard_name
: relative_humidityunits
: %
- RH_ICE_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: RH_ICE_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 1long_name
: Combined uncertainty estimate for RH_ICEunits
: %
- RH_LIQ_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: RH_LIQ_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 1long_name
: Combined uncertainty estimate for RH_LIQunits
: %
Flags
WeightOnWheels
This module simply provides the aircraft weight-on-wheels flag, recorded on the rear core console. A value of 1 indicates weight on wheels (i.e. the aircraft is on the ground) and a value of 0 indicates no weight on wheels (i.e. the aircraft is airborne).
Outputs
- WOW_IND
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]coordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 1long_name
: Weight on wheels indicatorunits
: 1
Flags
WetMach
This module calculate a moist-air Mach number using RVSM pressure
measurements and the volume mixing ratio from the flush mounted WVSSII
(assumed to identify itself as WVSS2A
).
Moist-air Mach number, \(M\), is given by
where
and
Here \(c_{pd}\) and \(c_{vd}\) are specific heats for dry air at constant pressure and volume, respectively, \(\epsilon\) is the ratio of the molecular mass of water to that of dry air, and the specific humidity, \(q_h\), is given by
where \(V = 1000000\times\text{vmr}_\text{WVSS2F}\).
The module also provides the parameter SH_GAMMA
, which is the ratio of
specific heats at constant pressure and constant volume, along with
uncertainty estimates for MACH
and SH_GAMMA
. The former is a
combination from uncertainties in the corrected WVSS2 VMR and the
uncertainty reported in BAe Reoprt 126, while the latter arises from the
uncertainty in the corrected WVSS2 VMR.
Outputs
- MACH
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: MACH_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Moist air Mach derived from WVSS-II(F) and RVSMunits
: 1
- SH_GAMMA
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SH_GAMMA_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: physicalMeasurementfrequency
: 32long_name
: Ratio of specific heats at constant pressure and constant pressureunits
: 1
- SH_GAMMA_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: SH_GAMMA_CU_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 32long_name
: Uncertainty estimate for SH_GAMMAunits
: 1
- MACH_CU
_FillValue
: -9999actual_range
: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]ancillary_variables
: MACH_CU_FLAGcoordinates
: <str: derived_from_file optional>coverage_content_type
: auxiliaryInformationfrequency
: 32long_name
: Uncertainty estimate for moist-air Machunits
: 1
Flags
Variables in this module use bitmask flags. Some, all or none of these flags may be applied to each variable. Interrogate flag variable attributes flag_masks
and flag_meanings
to find the flags for each variable.
aircraft_on_ground
- The aircraft is on the ground, as indicated by the weight-on-wheels indicator