Dear All,
I'd just like to reinforce John's last point that the semantics of 'instrument' and 'platform' are becoming blurred in these discussions. From my perspective as one who has to map to CF datasets I would prefer it if the semantics of terms used in Standard Names had a universally understood meaning.
Another point that struck me from John's response is that when we do have multiple data streams sharing a single Standard Name, we need to ensure that there are objective criteria (i.e. not plaintext in the longname) that enable each stream to be uniquely identified. Otherwise, even 'common concepts' (which incidentally will be worked during a workshop in November) won't deliver interoperability.
Cheers, Roy.
-----Original Message-----
From: cf-metadata-bounces at cgd.ucar.edu [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf Of Aleksandar Jelenak
Sent: 20 October 2010 01:33
To: cf-metadata at cgd.ucar.edu
Subject: Re: [CF-metadata] New standard names for satellite obs data
Dear Evan,
Thanks for your suggestions.
Evan Manning wrote on 10/18/10 11:30 PM:
> The names below mix "satellite" and "instrument" differently than I'm
> used to.
I started with "satellite_*" names but then wanted to generalize since
remote sensing instruments are not only carried on satellites. But you
brought up an important distinction that the observation geometry of an
instrument can be different from the generic one associated with the
entire spacecraft.
> I recommend changing:
> instrument_zenith_angle -> satellite_zenith_angle
> instrument_azimuth_angle -> satellite_azimuth_angle
> satellite_scan_angle -> satellite_view_angle
I think the "instrument_*" names are more applicable as they allow for
either instrument-specific or spacecraft-generic geometries. I also
think being able to distinguish between the two observation geometries
is important and would like to have sets of standard names for both. So
a data provider can clearly signal what is given, even for data from the
same instrument.
To summarize:
1) Use "instrument_zenith_angle", "instrument_azimuth_angle", and
"instrument_scan_angle" for precise, instrument-specific observation
geometry.
2) Use "platform_zenith_angle", "platform_azimuth_angle", and
"platform_view_angle" for generic satellite (here generalized to
"platform") observation geometry.
3) Mixing names from these two sets is allowed, whatever is more
applicable for the zenith, azimuth, and scan/view angle data.
Too complicated?
> And add:
> instrument_scan_angle
> The angle between the line of sight from an instrument and its
> reference scan position.
Agree.
-Aleksandar
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Received on Wed Oct 20 2010 - 01:46:21 BST
