Standard Names For Satellite Observations

The Climate and Forecast (CF) metadata convention maintains a list of standard names for data stored in variables of a netCDF file. Not many standard names in that list are relevant to satellite observation data so additional names are proposed here. The new names and accompanying information will follow the CF guidelines.

Proposed Names

Submitted By: Global Space-based Inter-Calibration System

Standard name	instrument_channel_identifier or sensor_band_identifier
Canonical units	N/A
Definition	Alphanumeric identifier of instrument's (sensor's) channel (band).

Standard name	time_interval
Canonical units	s
Definition	An interval of time.

Standard name	datetime_iso8601
Canonical units	N/A
Definition	String containing date-time information in one of the ISO 8601 formats. Variables with this standard name cannot serve as coordinate variables.

Standard name	instrument_zenith_angle or sensor_zenith_angle
Canonical units	degree
Definition	The angle between the line of sight to the instrument (sensor) and the local zenith.

Standard name	platform_scan_angle
Canonical units	degree
Definition	The angle between the line of sight from the platform's reference point and the nadir line. Nadir is the direction given by the vertical from the platform looking towards the center of the Earth.

Standard name	instrument_azimuth_angle
Canonical units	degree
Definition	The horizontal angle between the line of sight to the instrument and a reference direction which is often due north. The angle is measured clockwise.

Standard name	relative_instrument_azimuth_angle
Canonical units	degree
Definition	Difference between two instrument_azimuth_angle values.

Standard name	toa_outgoing_spectral_radiance
Canonical units	mW m-2 sr-1 (cm-1)-1
Definition	"toa" means top of atmosphere; "outgoing" means emitted toward outer space; "spectral" means per unit wavenumber or as a function of wavenumber. Radiance is the radiant power per unit area in a particular direction per unit of solid angle.

Standard name	toa_outgoing_spectral_radiance_mean_within_collocation_target
Canonical units	mW m-2 sr-1 (cm-1)-1
Definition	An average of toa_outgoing_spectral_radiance observations from instrument's adjacent field of views within a collocation target. Collocation target is an area on the Earth's surface at which observations from at least two instruments are collected. Its size is defined by the instrument with the largest field of view footprint.

Standard name	toa_outgoing_spectral_radiance_stdev_within_collocation_target
Canonical units	mW m-2 sr-1 (cm-1)-1
Definition	Standard deviation of toa_outgoing_spectral_radiance observations from instrument's adjacent field of views within a collocation target. Collocation target is an area on the Earth's surface at which observations from at least two instruments are collected. Its size is defined by the instrument with the largest field of view footprint.

Standard name	toa_outgoing_spectral_radiance_mean_within_collocation_scene
Canonical units	mW m-2 sr-1 (cm-1)-1
Definition	An average of toa_outgoing_spectral_radiance observations within a collocation scene. Collocation scene is a grouping of instrument's adjacent field of views (FOVs) centered on a collocation target. Collocation target is an area on the Earth's surface at which observations from at least two instruments are collected. Its size is defined by the instrument with the largest FOV footprint. Collocation scene's size is typically about twice the size of its collocation target.

Standard name	toa_outgoing_spectral_radiance_stdev_within_collocation_scene
Canonical units	mW m-2 sr-1 (cm-1)-1
Definition	Standard deviation of toa_outgoing_spectral_radiance observations within a collocation scene. Collocation scene is a grouping of instrument's adjacent field of views (FOVs) centered on a collocation target. Collocation target is an area on the Earth's surface at which observations from at least two instruments are collected. Its size is defined by the instrument with the largest FOV footprint. Collocation scene's size is typically about twice the size of its collocation target.

Standard name	linear_term_of_spectral_radiance_correction_due_to_intercalibration
Canonical units	1
Definition	Linear term (slope) of the formula for correcting measured spectral radiance. The correction is derived from intercalibration between the monitored and the reference instrument. The resulting corrected spectral radiance of the monitored instrument becomes comparable to measured spectral radiance of the reference instrument. "Spectral" means per unit wavenumber or as a function of wavenumber. Radiance is the radiant power per unit area in a particular direction per unit of solid angle.

Standard name	constant_term_of_spectral_radiance_correction_due_to_intercalibration
Canonical units	mW m-2 sr-1 (cm-1)-1
Definition	Constant term (offset) of the formula for correcting measured spectral radiance. The correction is derived from intercalibration between the monitored and the reference instrument. The resulting corrected spectral radiance of the monitored instrument becomes comparable with measured spectral radiance of the reference instrument. "Spectral" means per unit wavenumber or as a function of wavenumber. Radiance is the radiant power per unit area in a particular direction per unit of solid angle.

Standard name	covariance_between_constant_and_linear_terms_of_spectral_radiance_correction
Canonical units	mW m-2 sr-1 (cm-1)-1
Definition	Covariance between constant_term_of_spectral_radiance_correction_due_to_intercalibration and linear_term_of_spectral_radiance_correction_due_to_intercalibration values.

Standard name	toa_brightness_temperature_of_standard_scene
Canonical units	K
Definition	"toa" means top of atmosphere. Brightness temperature of a body is the temperature of a black body which radiates the same power per unit solid angle per unit area at a given wavenumber. Standard scene is a target area with typical Earth surface and atmospheric conditions that is accepted as a reference. The top-of-atmosphere radiance of the standard scene is calculated using a radiative transfer model for a given viewing geometry. The resultant top-of-atmosphere spectral radiance is then integrated with an instrument's spectral response function and converted to equivalent brightness temperature.

Standard name	toa_brightness_temperature_bias_at_standard_scene_wrt_intercalibration
Canonical units	K
Definition	The difference between top-of-atmosphere (TOA) brightness temperature of the reference instrument and TOA brightness temperature of the monitored instrument. This TOA brightness temperature difference is a measure of calibration difference between the monitored and reference instruments. Standard scene is a target area with typical Earth surface and atmospheric conditions that is accepted as a reference. Brightness temperature of a body is the temperature of a black body which radiates the same power per unit solid angle per unit area at a given wavenumber. TOA brightness temperature of the standard scene is calculated using a radiative transfer simulation for a given viewing geometry. The resultant top-of-atmosphere spectral radiance is then integrated with each instrument's spectral response functions and converted to equivalent brightness temperature.

Standard name	central_wavelength
Canonical units	m
Definition	The central wavelength of a radiometer band or channel.

Standard name	central_wavenumber
Canonical units	1/m
Definition	The central wavenumber (frequency) of a radiometer band or channel.

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Table Template for Standard Name Proposals

Standard name	...standard name...
Canonical units	...units...
Definition	...text...