20051117: MAKNAV mod

>From: "Valentijn Venus" <address@hidden>
>Organization: ITC
>Keywords: 200511171722.jAHHMk7s019022 McIDAS MAKNAV

Hi Valentijn,

>In your last message you wrote:
>
>>My inclination is to add support to MAKNAV to extract the navigation
>>block out an existing image and write it into the target.
>
>Do you have this adjusted MAKNAV program which can do this?

Yes, I have modified MAKNAV (maknav.pgm).  I havn't had a chance
to really test the mods yet, however.  I will send you a copy of
the code as soon as I do some testing.

>Secondly, in addition to GRIB2 formatted product, EUMETCAST also
>distibutes in GRIB. Total Ozone for example. I have no experience what
>so ever with configuring the GRBFILER.CFG, but would like to be able to
>serve this product to my students.

I don't have any experience with using McIDAS-XCD to file grib/bufr
producs, but I have had the occasion to look into this a bit
recently for another user.  The idea is that the McIDAS-XCD data
monitor DMBIN -- if set active -- will file grib and bufr products
that are "ingested" by the ingester ingebin.k.  In the typical
Unidata context, McIDAS-XCD data ingesters (ingetext.k for non-binary
data and ingebin.k for binary data) are fed products by the Unidata
LDM.  In the more general case, these processes might be ingesting
data from a feed from the ingesting machine's serial port or some other
mechanism.

The question is if you think that DMBIN is going to put the GRIB
messages into a format that can be used by McIDAS?  It doesn't.

What you may want to do is download the gribdec.tar.gz bundle from
our passworded McIDAS FTP site:

machine:   ftp.unidata.ucar.edu
user:      umcidas
pass:      uni_mcidas
directory: unix/gribdec
file:      gribdec.tar.gz

This bundle contains the GRIB decoding part of the XCD package in
a format that, when built, is run from the Unix command line.
You would build the package on a system on which McIDAS is installed
and then run either the GRIB -> GRID decoder gribdec.k or the
GRIB -> IMAGE converter grib2img.k.  In the former case, you would
end up with fields decoded into McIDAS GRID files, and in the
latter case you would end up with fields converted to images
in McIDAS AREA files.

>Attached you find an example file,
>and the GRIB headers at the following site:
>http://www.eumetsat.int/idcplg?IdcService=3DSS_GET_PAGE&nodeId=3D520&l=3D=
>en =20

The question now is whether or not the GRIB decoding code will
work with your GRIB files.  I will try converting the example
file you included tomorrow or this weekend and let you know the results.

>Can you please point me to a "how to"?

After I determine if the decoding works without error, I will give
you a step by step for building the package (simple) and how to
run the decoders (also simple).  I may need, however, to modify
some code to handle your GRIB messages or even create one or more
GRIB definition tables.  The need for specific tables is one reason
that I _hate_ GRIB:  it is not self-contained, so I can't for the
life of me understand why it was picked as a WMO standard!

Cheers,

Tom
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