In the CF-1.6 and CF-1.7 draft doc, in section H.2, we have:
"It is recommended that there should be station variables with
standard_name attributes " platform_name ", " surface_altitude " and ?
platform_id ? when applicable."
Why is this "surface_altitude" instead of "platform_altitude"?
In the ocean, we have lots of upward-looking Acoustic Doppler Current
Profilers (ADCP), where the instrument with transducer and other
sensors is located some distance below the ocean surface. While
velocity and other properties are measured in vertical bins above the
instrument (timeSeriesProfile), other properties like pressure and
temperature are measured at the instrument.
Since the instrument is not at the surface, it seems misleading to use
the standard_name "surface_altitude" instead of "platform_altitude",
particularly when we already have "platform_name" and "platform_id".
In this example CF_1.6 ADCP dataset:
http://geoport.whoi.edu/thredds/dodsC/usgs/data2/rsignell/data/adcp/7201adc-a_cf16.nc.html
the variable "platform_altitude" has a value of -10.4522 m:
http://geoport.whoi.edu/thredds/dodsC/usgs/data2/rsignell/data/adcp/7201adc-a_cf16.nc.ascii?platform_altitude
but we are forced to use a standard_name of "surface_altitude".
Why not "platform_altitude"?
Thanks,
Rich
--
Dr. Richard P. Signell (508) 457-2229
USGS, 384 Woods Hole Rd.
Woods Hole, MA 02543-1598
Received on Thu Sep 18 2014 - 07:40:36 BST
