[Met_help] [rt.rap.ucar.edu #46988] History for Question about user-created mask-poly files in pb2nc configuration

[RAL HelpDesk {for John Halley Gotway}]

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  Initial Request
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Hello,

I've been creating my own user-created mask-poly files for my pb2nc configuration, and receive the following error when the polygon gets too close to the poles:

 MaskPoly::load() -> encountered latitude value too close to a pole, (Lat, Lon) = (-90, -170) in
mask poly file "/glade/data02/dsswork/tcram/ds337.0/data/poly/pb2nc_4378.poly"

Is there a latitudinal limit on how close the polygon can get to the pole without returning this error?

Thanks for the help,
- Tom Cram

Thomas Cram
NCAR / CISL / DSS
303-497-1217
tcram at ucar.edu





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  Complete Ticket History
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Subject: Re: [rt.rap.ucar.edu #46988] Question about user-created mask-poly  files in pb2nc configuration
From: John Halley Gotway
Time: Fri May 20 22:09:07 2011

Tom,

That error is coming from the MaskPoly::load function defined in the
file
METv3.0.1/lib/vx_analysis_util/mask_poly.cc.  It looks like we're not
allowing any points within 1.0 degrees of latitude to either pole.
I'm
not certain why we have that limitation in there, but I do know issues
often arise at the poles.

You mention that you're using the polyline in the context of PB2NC.
For
PB2NC it's not really a problem to define your observation retention
area
a bit larger than what you're actually going to verify.  So you have
some
flexibility in how you define that retention area.

Please try playing around with it a bit.  If you continue having
problems
defining that area, we're happy to help.  Just send us the lat/lon
polyline you're using and point us to a sample PREPBUFR point
observation
file you're trying to process.

Thanks,
John Halley Gotway
met_help at ucar.edu


>
> Fri May 20 15:27:52 2011: Request 46988 was acted upon.
> Transaction: Ticket created by tcram at ucar.edu
>        Queue: met_help
>      Subject: Question about user-created mask-poly files in pb2nc
> configuration
>        Owner: Nobody
>   Requestors: tcram at ucar.edu
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=46988 >
>
>
> Hello,
>
> I've been creating my own user-created mask-poly files for my pb2nc
> configuration, and receive the following error when the polygon gets
too
> close to the poles:
>
>  MaskPoly::load() -> encountered latitude value too close to a pole,
(Lat,
> Lon) = (-90, -170) in
> mask poly file
> "/glade/data02/dsswork/tcram/ds337.0/data/poly/pb2nc_4378.poly"
>
> Is there a latitudinal limit on how close the polygon can get to the
pole
> without returning this error?
>
> Thanks for the help,
> - Tom Cram
>
> Thomas Cram
> NCAR / CISL / DSS
> 303-497-1217
> tcram at ucar.edu
>
>
>
>



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