SPIF Extended Vocabulary

Introduction

This document provides details of the spif_extended_example data product.

The standard REQUIRES that any SPIF compliant file contain a minimum set of groups, variables, and attributes. Any additional included vocabulary must not conflict with the mandatory vocabulary.

Vocabulary

/

Description:

This dataset contains fabricated raw image data for an imaginary optical array probe, the OAP100, and a CCD based imager called a CCD001. Also included may be aircraft position data and probe housekeeping data.

File Pattern:

arbitrary_images_[0-9]{8}_v001.nc

References:

data documentation | SPIF standard

Group Attributes:

• Conventions: CF-1.9, ACDD-1.3, SPIF-0.1

• title: <str: derived_from_file>

• summary: <str: derived_from_file>

• references: <str: derived_from_file>

• comment: <str: derived_from_file optional>

• history: <str: derived_from_file>

• creator_name: ARO

• creator_institution: Abitrary Research Organisation

• creator_address: A Building, Campus District, Town, Country.

• creator_email: info@arbitrary.org

• creator_url: https://www.arbitrary.org

• creator_type: institution

• date_created: <str: derived_from_file>

• imager_groups: OAP100, CCD001

• source: In situ measurements

• project: ACC - Arbitrary Cloud Campaign

• platform: Good Airplane v3

• platform_type: aircraft

• deployment_mode: air

• flight_date: <str: derived_from_file>

• flight_number: <str: derived_from_file>

• time_coverage_duration: <str: derived_from_file>

• time_coverage_start: <str: derived_from_file>

• time_coverage_end: <str: derived_from_file>

• geospatial_bounds: <str: derived_from_file>

• geospatial_bounds_crs: <str: derived_from_file>

• geospatial_lat_max: <float32: derived_from_file>

• geospatial_lat_min: <float32: derived_from_file>

• geospatial_lat_units: <str: derived_from_file>

• geospatial_lon_max: <float32: derived_from_file>

• geospatial_lon_min: <float32: derived_from_file>

• geospatial_lon_units: <str: derived_from_file>

• geospatial_vertical_max: <float32: derived_from_file>

• geospatial_vertical_min: <float32: derived_from_file>

• geospatial_vertical_units: <str: derived_from_file>

• geospatial_vertical_positive: <str: derived_from_file>

• keywords: CLOUD DROPLET DISTRIBUTION,

• keywords_vocabulary: Global Change Master Directory (GCMD)

• acknowledgement: This data has been fabricated to replicate that from imaginary but non-existant optical array probe (OAP) and CCD-based imager. It is included as part of the SPIF vocal project repository as an example only.

/platform

Description:

Time series data from platform that can be used to process image data. Times use the RAF format where the Time dimension is integer seconds and the sps32 dimension gives the 32 Hz data in each second.

Group Attributes:

• group_type: platform

• comment: <str: derived_from_file optional>

Group Variables:

Time

Datatype:

<int32>

Dimensions:

Time

Attributes:

• long_name: Time of measurement

• standard_name: time

• calendar: gregorian

• coverage_content_type: coordinate

• frequency: 32

• units: <str: derived_from_file>

• _FillValue: -9999

altitude

Datatype:

<float32>

Dimensions:

Time, sps32

Attributes:

• long_name: Platform altitude

• standard_name: altitude

• coverage_content_type: physicalMeasurement

• frequency: 32

• units: <str: derived_from_file>

• actual_range: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]

• axis: Z

• positive: up

• _FillValue: -9999.0

latitude

Datatype:

<float32>

Dimensions:

Time, sps32

Attributes:

• long_name: Platform latitude

• standard_name: latitude

• coverage_content_type: physicalMeasurement

• source: <str: derived_from_file>

• frequency: 32

• units: <str: derived_from_file>

• actual_range: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]

• axis: Y

• _FillValue: -9999.0

longitude

Datatype:

<float32>

Dimensions:

Time, sps32

Attributes:

• long_name: Platform longitude

• standard_name: longitude

• coverage_content_type: physicalMeasurement

• source: <str: derived_from_file>

• frequency: 32

• units: <str: derived_from_file>

• actual_range: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]

• axis: X

• _FillValue: -9999.0

tas

Datatype:

<float32>

Dimensions:

Time, sps32

Attributes:

• long_name: Platform true air speed

• standard_name: platform_speed_wrt_air

• coverage_content_type: physicalMeasurement

• source: <str: derived_from_file>

• frequency: 32

• units: <str: derived_from_file>

• actual_range: [‘<float32: derived_from_file>’, ‘<float32: derived_from_file>’]

• _FillValue: -9999.0

/OAP100

Description:

Instrument group of raw and processed data for this instrument.

Group Attributes:

• group_type: imager

• instrument: <str: derived_from_file optional>

• instrument_name: OAP100

• instrument_long_name: Optical Array Probe - 100um

• instrument_description: Imaginary Optical Array Probe with 100 um pixel resolution and four levels of grayscale.

• instrument_location: <str: derived_from_file>

• instrument_orientation: <str: derived_from_file>

• instrument_manufacturer: OAP Instruments Ltd

• instrument_model: OAP100-GS

• instrument_serial_number: 001

• instrument_software: <str: derived_from_file optional>

• instrument_software_version: <str: derived_from_file optional>

• instrument_fimware: <str: derived_from_file optional>

• references: https://www.OAP_instruments.com/manuals

• raw_filenames: <str: derived_from_file optional>

Group Variables:

color_level

REQUIRED

Datatype:

<float32>

Dimensions:

pixel_colors

Attributes:

• long_name: Lower bound of obscuration/grayscale/color level

• coverage_content_type: auxiliaryInformation

• units: 1

• _FillValue: -9999.0

• comment: Obscuration/grayscale/color level corresponding to each value of pixel_colors. For example, a grayscale OAP may have lower-bound shadow levels of [0, 0.25, 0.5, 0.75].

array_size

REQUIRED

Datatype:

<int32>

Dimensions:

array_dimensions

Attributes:

• long_name: Number of pixels in detector along each dimension

• coverage_content_type: auxiliaryInformation

• units: 1

• _FillValue: -9999

image_size

REQUIRED

Datatype:

<int32>

Dimensions:

array_dimensions

Attributes:

• long_name: Number of pixels across an image along each array dimension

• coverage_content_type: auxiliaryInformation

• units: 1

• _FillValue: -9999

• comment: If images are of varying size along a dimension then use _FillValue for that dimension.

resolution

REQUIRED

Datatype:

<float32>

Dimensions:

array_dimensions

Attributes:

• long_name: Pixel resolution along each dimension

• coverage_content_type: auxiliaryInformation

• units: <str: derived_from_file>

• _FillValue: -9999.0

wavelength

REQUIRED

Datatype:

<float32>

Dimensions:

Attributes:

• long_name: Wavelength of laser used for imaging particles

• coverage_content_type: auxiliaryInformation

• units: <str: derived_from_file>

• _FillValue: -9999.0

pathlength

REQUIRED

Datatype:

<float32>

Dimensions:

Attributes:

• long_name: Optical path length of imaging region

• coverage_content_type: auxiliaryInformation

• units: <str: derived_from_file>

• _FillValue: -9999.0

• comment: For OAPs the pathlength will be arm separation distance.

color_value

Datatype:

<uint8>

Dimensions:

pixel_colors

Attributes:

• long_name: Byte values of image associated with each color_level value

• coverage_content_type: auxiliaryInformation

• units: 1

• _FillValue: 255

resolution_error

Datatype:

<float32>

Dimensions:

array_dimensions

Attributes:

• long_name: Uncertainty of pixel resolution of instrument for each dimension.

• coverage_content_type: auxiliaryInformation

• units: <str: derived_from_file>

• _FillValue: -9999.0

/OAP100/core

Description:

Decompressed and flattened raw image data

Group Attributes:

• group_type: core

Group Variables:

image

REQUIRED

Datatype:

<uint8>

Dimensions:

pixel

Attributes:

• long_name: 1-dimensional array of series of images

• coverage_content_type: image

• _FillValue: 255

timestamp

REQUIRED

Datatype:

<uint64>

Dimensions:

image_num

Attributes:

• long_name: Image arrival time

• standard_name: time

• units: <str: derived_from_file>

startpixel

REQUIRED

Datatype:

<uint32>

Dimensions:

image_num

Attributes:

• long_name: Array index for the first pixel of each image

• _FillValue: 4294967295

width

REQUIRED

Datatype:

<uint8>

Dimensions:

image_num

Attributes:

• long_name: Number of pixels across an image

• _FillValue: 255

height

REQUIRED

Datatype:

<uint8>

Dimensions:

image_num

Attributes:

• long_name: Number of slices/lines along an image

• _FillValue: 255

overload

REQUIRED

Datatype:

<byte>

Dimensions:

image_num

Attributes:

• long_name: Overload flag for each image

• _FillValue: -127

timestamp_flag

Datatype:

<byte>

Dimensions:

image_num

Attributes:

• long_name: Surety in determination of image arrival timestamp

• flag_values: <Array[byte]: derived_from_file>

• flag_meanings: <str: derived_from_file>

• _FillValue: -127

/OAP100/auxillary

Description:

Other probe data and housekeeping from data acquisition system. These are simple timeseries.

Group Attributes:

• group_type: other

• comment: 1 Hz housekeeping obtained from the auxillary datafile/s

• raw_filenames: <str: derived_from_file optional>

Group Variables:

Time

Datatype:

<int32>

Dimensions:

Time

Attributes:

• long_name: Time of measurement

• standard_name: time

• calendar: gregorian

• coverage_content_type: coordinate

• frequency: 1

• units: <str: derived_from_file>

• _FillValue: -9999

laser_power

Datatype:

<float32>

Dimensions:

Time

Attributes:

• long_name: Real-time measured laser output power

• coverage_content_type: physicalMeasurement

• frequency: 1

• units: mW

• _FillValue: -9999.0

laser_temperature

Datatype:

<float32>

Dimensions:

Time

Attributes:

• long_name: Laser temperature

• coverage_content_type: physicalMeasurement

• comment: Real-time measured laser diode temperature

• frequency: 1

• units: degC

• _FillValue: -9999.0

laser_current

Datatype:

<float32>

Dimensions:

Time

Attributes:

• long_name: Laser current

• coverage_content_type: physicalMeasurement

• comment: Real-time measured laser diode current

• frequency: 1

• units: mA

• _FillValue: -9999.0

/CCD001

Description:

Instrument group of raw and processed data for this instrument.

Group Attributes:

• group_type: imager

• instrument: <str: derived_from_file optional>

• instrument_name: CCD001

• instrument_long_name: CCD imager - 1um

• instrument_description: Imaginary CCD based imager with 1 um pixel resolution and 256 levels of grayscale.

• instrument_location: <str: derived_from_file>

• instrument_orientation: <str: derived_from_file>

• instrument_manufacturer: CCD Instruments Ltd

• instrument_model: CCD001

• instrument_serial_number: 001

• instrument_software: <str: derived_from_file optional>

• instrument_software_version: <str: derived_from_file optional>

• instrument_fimware: <str: derived_from_file optional>

• references: https://www.CCD_instruments.com/manuals

• raw_filenames: <str: derived_from_file optional>

Group Variables:

color_level

REQUIRED

Datatype:

<float32>

Dimensions:

pixel_colors

Attributes:

• long_name: Lower bound of obscuration/grayscale/color level

• coverage_content_type: auxiliaryInformation

• units: 1

• _FillValue: -9999.0

• comment: Obscuration/grayscale/color level corresponding to each value of pixel_colors. For example, a grayscale OAP may have lower-bound shadow levels of [0, 0.25, 0.5, 0.75].

array_size

REQUIRED

Datatype:

<int32>

Dimensions:

array_dimensions

Attributes:

• long_name: Number of pixels in detector along each dimension

• coverage_content_type: auxiliaryInformation

• units: 1

• _FillValue: -9999

image_size

REQUIRED

Datatype:

<int32>

Dimensions:

array_dimensions

Attributes:

• long_name: Number of pixels across an image along each dimension

• coverage_content_type: auxiliaryInformation

• units: 1

• _FillValue: -9999

• comment: If images are of varying size along a dimension then use _FillValue for that dimension.

resolution

REQUIRED

Datatype:

<float32>

Dimensions:

array_dimensions

Attributes:

• long_name: Pixel resolution along each dimension

• coverage_content_type: auxiliaryInformation

• units: <str: derived_from_file>

• _FillValue: -9999.0

wavelength

REQUIRED

Datatype:

<float32>

Dimensions:

Attributes:

• long_name: Wavelength of laser used for imaging particles

• coverage_content_type: auxiliaryInformation

• units: <str: derived_from_file>

• _FillValue: -9999.0

pathlength

REQUIRED

Datatype:

<float32>

Dimensions:

Attributes:

• long_name: Optical path length of imaging region

• coverage_content_type: auxiliaryInformation

• units: <str: derived_from_file>

• _FillValue: -9999.0

• comment: For OAPs the pathlength will be arm separation distance.

color_value

Datatype:

<uint8>

Dimensions:

pixel_colors

Attributes:

• long_name: Byte values of image associated with each color_level value

• coverage_content_type: auxiliaryInformation

• units: 1

• _FillValue: 255

resolution_error

Datatype:

<float32>

Dimensions:

array_dimensions

Attributes:

• long_name: Uncertainty of pixel resolution

• coverage_content_type: auxiliaryInformation

• units: <str: derived_from_file>

• _FillValue: -9999.0

/CCD001/core

Description:

Decompressed and flattened raw image data

Group Attributes:

• group_type: core

Group Variables:

image

REQUIRED

Datatype:

<uint8>

Dimensions:

pixel

Attributes:

• long_name: 1-dimensional array of series of images

• coverage_content_type: image

• _FillValue: 255

timestamp

REQUIRED

Datatype:

<uint64>

Dimensions:

image_num

Attributes:

• long_name: Image arrival time

• standard_name: time

• units: <str: derived_from_file>

startpixel

REQUIRED

Datatype:

<uint32>

Dimensions:

image_num

Attributes:

• long_name: Array index for the first pixel of each image

• _FillValue: 4294967295

width

REQUIRED

Datatype:

<uint8>

Dimensions:

image_num

Attributes:

• long_name: Number of pixels across an image

• _FillValue: 255

height

REQUIRED

Datatype:

<uint8>

Dimensions:

image_num

Attributes:

• long_name: Number of slices/lines along an image

• _FillValue: 255

overload

REQUIRED

Datatype:

<byte>

Dimensions:

image_num

Attributes:

• long_name: Overload flag for each image

• _FillValue: -127