platform_zenith_angle

complete
Created: Oct. 3, 2018
Proposer: Alison Pamment
Proposed Date: 2018-10-03
Update description of 'platform'.
Change Date: Oct. 3, 2018, 4:45 p.m.
Term: platform_zenith_angle
Unit: degree
Unit ref: UAAA
AMIP:
GRIB:
Standard names for "platform" describe the motion and orientation of the vehicle from which observations are made. Platforms include, but are not limited to, satellites, aeroplanes, ships, instruments and buoys. Platform zenith angle is the the angle between the line of sight to the platform and the local zenith at the observation target. This angle is measured starting from directly overhead and its range is from zero (directly overhead the observation target) to 180 degrees (directly below the observation target). Local zenith is a line perpendicular to the Earth's surface at a given location. "Observation target" means a location on the Earth defined by the sensor performing the observations. A standard name also exists for sensor_zenith_angle. For some viewing geometries the sensor and the platform cannot be assumed to be close enough to neglect the difference in calculated zenith angle.
Change Date: Oct. 3, 2018, 4:46 p.m.
Term: platform_zenith_angle
Unit: degree
Unit ref: UAAA
AMIP:
GRIB:
Platform zenith angle is the the angle between the line of sight to the platform and the local zenith at the observation target. This angle is measured starting from directly overhead and its range is from zero (directly overhead the observation target) to 180 degrees (directly below the observation target). Local zenith is a line perpendicular to the Earth's surface at a given location. "Observation target" means a location on the Earth defined by the sensor performing the observations. A standard name also exists for sensor_zenith_angle. For some viewing geometries the sensor and the platform cannot be assumed to be close enough to neglect the difference in calculated zenith angle. A "platform" is a structure or vehicle that serves as a base for mounting sensors. Platforms include, but are not limited to, satellites, aeroplanes, ships, buoys, instruments, ground stations, and masts.