Standard Names For Satellite Observations

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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 vertical.


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 radiative flux 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 an order of magnitude larger than 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 an order of magnitude larger than 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 with measured spectral radiance of the reference instrument. "Spectral" means per unit wavenumber or as a function of wavenumber. Radiance is the radiative flux 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 radiative flux 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. Standard scene is a physical model of the Earth surface and atmosphere that is accepted as a reference. This model is used in a radiative transfer simulation to calculate top-of-atmosphere radiance for a given viewing geometry. The resultant top-of-atmosphere 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 intercalibrated simulated top-of-atmosphere (TOA) brightness temperature of the reference instrument and simulated TOA brightness temperature of the monitored instrument. Intercalibration is a process of deriving an equation by which observations from the monitored instrument become comparable to observations from the reference instrument. This difference is a measure of the quality of intercalibration. Standard scene is a physical model of the Earth surface and atmosphere 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. TOA brightness temperatures for both the monitored and referenced instruments are calculated using the standard scene model and a radiative transfer simulation. The resultant top-of-atmosphere radiance is then integrated with each instrument's spectral response functions and converted to equivalent brightness temperature.



Table Template for Standard Name Proposals

Standard name
Canonical units
Definition