[Cosmic_announce] User question: switch impact parameter for impact height in atmPrf files?

[Doug Hunt]

Hi Dave:  Thanks for your reply.  We will supply sample files if we decide 
to go ahead with this change.

In truth, we are not proposing a change to the BUFR stream--that will stay 
as it has been.

Regards,

   Doug

dhunt at ucar.edu
Software Engineer
UCAR - COSMIC, Tel. (303) 497-2611

On Mon, 14 May 2012, Offiler, Dave wrote:

> Hi Doug,
>
> We don't use atmPrf netCDF files operationally, but of course we do
> provide a reader/conversion
> tool ('ucar2ropp') within the ROPP software so atmPrf (and several other
> of your RO files) can
> be processed by other components using a common interface for all RO
> data.
>
> We'll do a quick review of what your proposal would mean for the
> package, but as a quick response,
> we'd likely handle impact heights in the netCDF (replacing impact
> parameter) by just re-calculating I.P.
> in ucar2ropp (given that local RoC remains present) when I.H. is found
> in the netCDF but no I.P.
>
> Software-wise this ought to be a simple update, but we'd need to roll
> out the patch to ROPP users who _are_
> processing atmPrf files. Hence if you do decide to go ahead, we'd
> appreciate an early example
> atmPrf file to test with & give us a chance to roll out an updated
> ucar2ropp.f90 to users before you make
> the change for real.
>
> I assume you're _not_ proposing a similar change to the BUFR stream?
>
> Dave
> --
> David Offiler   Head Satellite Active Sensing Group
> Met Office   FitzRoy Road   Exeter   EX1 3PB   United Kingdom
> Tel: +44 (0)1392 88 6298    Fax: +44 (0)1392 88 5681
> E-mail: dave.offiler at metoffice.gov.uk   http://www.metoffice.gov.uk
>
> -----Original Message-----
> From: cosmic_announce-bounces at ucar.edu
> [mailto:cosmic_announce-bounces at ucar.edu] On Behalf Of Doug Hunt
> Sent: 11 May 2012 21:52
> To: cosmic_announce at ucar.edu
> Cc: Sergey Sokolovskiy; COSMIC operations group
> Subject: [Cosmic_announce] User question: switch impact parameter for
> impact height in atmPrf files?
>
> Greetings CDAAC users:
>
> We are currently revising our inversion code and are trying to do some
> small clean-up of the atmPrf data format.
>
> atmPrf files use our high-resolution netCDF output format defined at:
>
> http://cosmic-io.cosmic.ucar.edu/cdaac/cgi_bin/fileFormats.cgi?type=atmP
> rf
>
> We are considering switching the impact parameter column in this file
> ('Impact_parm' in the netCDF file) to impact height.  'Impact parameter'
>
> is the independent height variable for bending angle profiles stored in
> atmPrf files.  It measures the distance to the ray path from the center
> of sphericity of the earth.  It is not a very convenient height variable
> since all of it's values are in the 6000 km range.
>
> 'Impact height' is simply impact parameter with the earth's local radius
> of curvature (the 'rfict' attribute in the atmPrf file) subtracted off.
> Impact height ranges from ~2km to ~60km and as such it is more
> convenient for use in plotting and generating statistics.
>
> If anyone would have an objection to us making this change to atmPrf
> files starting in several months, could you please email me (Doug Hunt,
> dhunt at ucar.edu)?
>
> Thanks much!
>
> --Doug Hunt
>
> dhunt at ucar.edu
> Software Engineer
> UCAR - COSMIC, Tel. (303) 497-2611
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