Dear Jim, Nan, Roy,
Thank you all for the quick responses.
Nan, you are correct that platform_id and platform_name are listed in the editor simply to update the description of 'platform' in their definitions. Sorry if that wasn't clear. There are several other 'under discussion' names in the list, purely because of the platform text:
angle_of_rotation_from_solar_azimuth_to_platform_azimuth;
platform_azimuth_angle;
platform_speed_wrt_air;
platform_speed_wrt_ground;
platform_speed_wrt_sea_water;
platform_view_angle;
platform_zenith_angle;
relative_platform_azimuth_angle.
The standard names platform_id and platform_name were introduced in V25 of the standard name table (July 2013) so they are not new. They were originally proposed in CF trac #37 as station_wmo_id and station_description. Later on it was agreed that the names should be generalized to say 'platform' so that they could be used for any observing location, not just wmo stations. The trac ticket was under discussion for a long time and there was concern that some data may have been written with the original versions of the names, so they have been retained as aliases of the later versions. The names and aliases do both appear in the standard name table in the usual way.
Jim, as you say, I included 'instrument' as a type of platform because Nan requested this in the original platform heave discussion (
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2018/020195.html). Nan wrote
> Also, not to get too far into the weeds, but many of the platform terms are important for instruments like ADCPs, so I'd just like to confirm that these
> definitions - and the names themselves - can be used to describe instruments, not just vehicles 'e.g. aeroplane, ship or satellite'. We already use pitch
> roll and yaw for these instruments on surface moorings, and I hope (and assume) this is legal.
Roy, many thanks for offering to review the definitions. It's always good to have someone check them over thoroughly before publication.
Best wishes,
Alison
------
Alison Pamment Tel: +44 1235 778065
NCAS/Centre for Environmental Data Archival Email: alison.pamment at stfc.ac.uk
STFC Rutherford Appleton Laboratory
R25, 2.22
Harwell Oxford, Didcot, OX11 0QX, U.K.
-----Original Message-----
From: CF-metadata <cf-metadata-bounces at cgd.ucar.edu> On Behalf Of Nan Galbraith
Sent: 03 October 2018 20:25
To: cf-metadata at cgd.ucar.edu
Subject: Re: [CF-metadata] Platform Heave
Thanks, Alison! I haven't read through all of these yet, but based on
your email and
reading the ones I'm especially interested in, it looks great. I do have
a quick question,
though.
I see? that platform_id and platform_name are 'under discussion', and
reference this
thread as the 'CF mailing list link'.? Are they just on the the standard
names editor
list because the definitions will have the description of platform
updated (and moved
to the end), or are these actually changing in some other way?
Also, I looked at the standard name table and found these:
/platform_id//
//alias: station_wmo_id//
//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.? A variable with the standard name of platform_id
contains strings
which help to identify the platform from which an observation was made.
For example, this
may be a WMO station identification number. //
////
//platform_name//
//alias: station_description//
//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. A variable with the standard name of
platform_name contains strings
which help to identify the platform from which an observation was made.
For example, this
may be a geographical place name such as "South Pole" or the name of a
meteorological
observing station./
I'm curious why they have aliases, especially since those aliases are
not in the standard name
table.? Will those be removed when these definitions are updated? Also,
has there been any
discussion about updating these (or the guidance for them) in any way,
or are they purposely
left vague?
I don't want to take this thread off into another direction, I'm just
curious about these terms.
Thanks again -
Nan
On 10/3/18 1:10 PM, Alison Pamment - UKRI STFC wrote:
> Dear Jim, Roy, Nan, Jonathan, et al.,
>
> I have drawn together what I hope is the final list for the platform names.
>
> We seem to be agreed on the need to have triplets of names to cope with opposite sign conventions and the case where the sign convention is unknown. I've followed Roy's comment http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2018/020540.html regarding cross-referencing in the definitions, i.e. adding the statement to only choose the unsigned names if the convention is truly unknown. I plan to create aliases for some of the existing names as follows:
> platform_yaw_angle -> platform_yaw
> platform_pictch_angle -> platform_pitch
> platform_roll_angle > platform_roll
> to make them consistent with the new names. In addition to Jim's 12th September proposals (http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2018/020513.html), new names for platform_sway, platform_sway_rate, platform_surge and platform_surge_rate are needed to provide complete triplets of names for all the quantities.
>
> The definitions of the new quantities are all based on Jim's text, with the 'platform' description moved to the end. 'Instrument' has been added to the list of platforms as I think this was requested by Nan earlier in the discussion. (I think we can regard an 'instrument' as a way to mount one or more 'sensors'). The definitions of all existing platform names will be updated for consistency.
>
> On a grammatical point, I noticed that the definitions of yaw/pitch/roll/surge rate in Jim's message all said "Yaw/pitch/roll/surge rate *might not* include changes to the "at rest" position of the platform ..." whereas the definitions of sway/heave rate said "Sway/heave rate *may not* include changes to the "at rest" position of the platform ...". I have changed all the definitions to say "might not" instead of "may not" as I think the latter could sound like we are prohibiting the inclusion of changes to the "at rest" position, which I don't think is the intention. Please correct me if this is wrong!
>
> I have added all the names into the standard names editor: http://cfeditor.ceda.ac.uk/proposals/1?status=active&namefilter=platform&proposerfilter=&descfilter=&unitfilter=&yearfilter=&commentfilter=&filter+and+display=Filter. To save copying and pasting all the text into this message, please use the link to check through the full list. N.B. You can refine the filters to view smaller subsets of names together, e.g., 'platform_sway'. If no objections or suggestions for further changes are received, the names will be accepted in their current form and published on 15th October.
>
> Best wishes,
> Alison
>
> ------
> Alison Pamment Tel: +44 1235 778065
> NCAS/Centre for Environmental Data Archival Email: alison.pamment at stfc.ac.uk
> STFC Rutherford Appleton Laboratory
> R25, 2.22
> Harwell Oxford, Didcot, OX11 0QX, U.K.
>
> _______________________________________________
> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>
--
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* Nan Galbraith Information Systems Specialist *
* Upper Ocean Processes Group Mail Stop 29 *
* Woods Hole Oceanographic Institution *
* Woods Hole, MA 02543 (508) 289-2444 *
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Received on Thu Oct 04 2018 - 05:13:08 BST
