[Met_help] [rt.rap.ucar.edu #44987] History for Question about mask_grid in pb2nc

[RAL HelpDesk {for John Halley Gotway}]

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  Initial Request
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I need clarification on the usage of mask_grid in the pb2nc configuration file.  If I specify a pre-defined NCEP grid with the mask_grid parameter, does pb2nc simply retain all observations which occur inside the grid boundaries, or does it interpolate the data to the actual grid points?  I'm thinking it's the former, but just want to verify this with you guys.

Thanks,
- Tom


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 #44987] Question about mask_grid in pb2nc
From: John Halley Gotway
Time: Tue Mar 01 14:42:18 2011

Tom,

Yes, it is the former.  You can specify a mask_grid using the pre-
defined NCEP grids or a mask_poly to specify a user-define polyline
region.  The PREPBUFR observation files contain data for either
North America (NDAS) or the entire globe (GDAS).  These masking
options can be used to reduce the number of observations retained down
to your actual region of interest.  If the observation falls
inside the masking region, it's retained, and if not, it's tossed.
There is no interpolation being performed.

Thanks,
John Halley Gotway
met_help at ucar.edu

On 03/01/2011 02:37 PM, RAL HelpDesk {for Thomas Cram} wrote:
> I need clarification on the usage of mask_grid in the pb2nc
configuration file.  If I specify a pre-defined NCEP grid with the
mask_grid parameter, does pb2nc simply retain all observations which
occur inside the grid boundaries, or does it interpolate the data to
the actual grid points?  I'm thinking it's the former, but just want
to verify this with you guys.

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