Difference between revisions of "Standard Names For Satellite Observations"
From Earth Science Information Partners (ESIP)
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|'''Definition''' | |'''Definition''' | ||
| − | |Alphanumeric identifier of | + | |Alphanumeric identifier of a sensor's band. |
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{| class="wikitable" | {| class="wikitable" | ||
|'''Standard name''' | |'''Standard name''' | ||
| − | | | + | |sensor_zenith_angle |
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|'''Canonical units''' | |'''Canonical units''' | ||
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|'''Definition''' | |'''Definition''' | ||
| − | |The angle between the line of sight to the | + | |The angle between the line of sight to the sensor and the local zenith. |
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|'''Definition''' | |'''Definition''' | ||
| − | | The central wavelength of a sensor's band. | + | | The central wavelength of a sensor's band, calculated as the first moment of the band's spectral response function. |
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|'''Definition''' | |'''Definition''' | ||
| − | | The central wavenumber of a sensor's band. | + | | The central wavenumber of a sensor's band, calculated as the first moment of the band's spectral response function. |
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|'''Definition''' | |'''Definition''' | ||
| − | | The central frequency of a sensor's band. | + | | The central frequency of a sensor's band, calculated as the first moment of the band's spectral response function. |
|} | |} | ||
Revision as of 20:21, August 27, 2012
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.
Sensor vs. Instrument and Band vs. Channel
Proposed Names
| Standard name | sensor_band_identifier |
| Canonical units | N/A |
| Definition | Alphanumeric identifier of a sensor's 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 | sensor_zenith_angle |
| Canonical units | degree |
| Definition | The angle between the line of sight to the 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 sensor's band, calculated as the first moment of the band's spectral response function. |
| Standard name | central_wavenumber |
| Canonical units | m-1 |
| Definition | The central wavenumber of a sensor's band, calculated as the first moment of the band's spectral response function. |
| Standard name | central_frequency |
| Canonical units | Hz |
| Definition | The central frequency of a sensor's band, calculated as the first moment of the band's spectral response function. |
Table Template for Standard Name Proposals
| Standard name | ...standard name...
|
| Canonical units | ...units...
|
| Definition | ...text...
|
