[CF-metadata] New standard names for satellite obs data

From: Evan Manning <Evan.M.Manning>
Date: Mon, 18 Oct 2010 20:30:17 -0700

The names below mix "satellite" and "instrument" differently than I'm
used to. For AIRS we use satellite zenith & azimuth angles, since
it is the angle to the entire satellite, not just a single instrument.

We also have an instrument scan angle, along its own scan plan and
relative to its nominal "nadir" position, not to true nadir. We
sometimes calculate a satellite view angle from instrument
zenith angle. This is roughly equivalent to a scan angle but
explicitly divorced from actual instrument geometry and satellite
attitude.

I recommend changing:
  instrument_zenith_angle -> satellite_zenith_angle
  instrument_azimuth_angle -> satellite_azimuth_angle
  satellite_scan_angle -> satellite_view_angle
And add:
  instrument_scan_angle
    The angle between the line of sight from an instrument and its
    reference scan position.

  -- Evan

> 3) "instrument_zenith_angle" [degree]
> ??? The angle between the line of sight to the instrument and the local
> ??? vertical.

> 4) "satellite_scan_angle" [degree]
> ??? The angle between the line of sight from the satellite and the nadir
> ??? line. Nadir is the direction given by the vertical from the satellite
> ??? looking towards the center of the Earth.

> 5) "instrument_azimuth_angle" [degree]
> ??? 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.

> 6) "relative_instrument_azimuth_angle" [degree]
> ??? Difference between two instrument_azimuth_angle values.
Received on Mon Oct 18 2010 - 21:30:17 BST