[CF-metadata] Adding sensor_elevation_angle to standard_name

From: Martin Juckes - UKRI STFC <martin.juckes>
Date: Tue, 19 Mar 2019 09:56:56 +0000

Hello Ken,


this looks like a straight forward extension of existing names, but I'm puzzled by the definition of "zenith" in sensor_zenith_angle, where it is defined as "Local zenith is a line perpendicular to the Earth's surface at a given location." For the standard name "zenith_angle" the definition is different: "Zenith angle is the angle to the local vertical". The latter, with vertical defined by the direction of gravity, appears to be the standard usage: would you agree with this?


Is the reference to the Earth's surface in the definition of sensor_zenith_angle a mistake, which should be modified to bring it into line with zenith_angle, or is there a real need to have angles measured relative to the local plane of the Earth's surface?


For the sensor_elevation_angle, do you want a specific interpretation of "horizontal" (e.g. perpendicular to the direction of gravity), or is it acceptable to use this term with other interpretations of the reference horizontal plane?


regards,

Martin


________________________________
From: CF-metadata <cf-metadata-bounces at cgd.ucar.edu> on behalf of Kehoe, Kenneth E. <kkehoe at ou.edu>
Sent: 19 March 2019 00:27
To: CF Metadata List
Subject: [CF-metadata] Adding sensor_elevation_angle to standard_name

I would like to add sensor_elevation_angle to complement the existing sensor_azimuth_angle in the standard_name table.

proposed standard_name = sensor_elevation_angle

proposed canonical units = degree

proposed definition = sensor_elevation_angle is the angle measured in the vertical plane between the line of sight of the sensor and a horizontal plane perpendicular to local zenith. This angle is measured starting from the horizontal plane directly in front of sensor. The angle is positive above the horizontal plane, and negative below the horizontal plane. Local zenith is directly overhead. A standard name also exists for sensor_view_angle and sensor_zenith_angle.

Thanks,

Ken

--
Kenneth E. Kehoe
  Research Associate - University of Oklahoma
  Cooperative Institute for Mesoscale Meteorological Studies
  ARM Climate Research Facility - Data Quality Office
  e-mail: kkehoe at ou.edu<mailto:kkehoe at ou.edu> | Office: 303-497-4754

Received on Tue Mar 19 2019 - 03:56:56 GMT