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20040515: Can GEMPAK/N-AWIPS read zlib compress satellite images?

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  • Subject: 20040515: Can GEMPAK/N-AWIPS read zlib compress satellite images?
  • Date: Mon, 17 May 2004 11:04:51 -0600
Mike,

Second bullet of 5.6.k release announcement:

http://www.unidata.ucar.edu/projects/coohl/mhonarc/MailArchives/gempak/msg05384.html

I display them here in the zlib compressed format. Doing an "od -c" on your 
image should show something like:
% od -c VIS_20040517_1645 | more
0000000   T   I   G   W   0   1       K   N   E   S       1   7   1   6
0000020   4   5  \r  \r  \n   x 332

That is the wmo header followed by the start of the zlib block at byte 22.
If you have a "0" or "1" in byte 22, then the image is not zlib compressed.

Steve CHiswell
Unidata User SUpport

>From: Michael W Dross <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200405151648.i4FGmLtK029573

>
>
>
>
>Hi,
>
>Can the latest versions of GEMPAK read zlib compressed satellite imagery?
>
>The satellite imagery off NOAAPORT is compressed with the zlib compression,
>as is the NIDS.
>GEMPAK reads the NIDS compressed imagery, but the version I have running
>'L' does not read
>the compressed satellite imagery, I tested it on a sample file.
>
>I looked through the "Whats New" GEMPAK info, and I didn't see anything
>about reading
>zlib compressed satellite. I would have thought this was added along the
>line, after NOAAPORT
>started compressing satellite data.
>
>Thanks for you help, as always.
>
>Mike
>
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