20041104: Need to verify GRIB files via McIDAS

>From: Micah Epps <address@hidden>
>Organization: DRS Weather Systems, Inc.
>Keywords: 200411042307.iA4N7NvV017556 McIDAS-XCD GRIB decoding

Micah,

I just returned from travel, and wanted to touch base with you on
the McIDAS XCD GRIB decoding we discussed at the beginning of
November.

>Thanks.  Attached are GRIB and BUFR files as well.  You may need the
>"gribtab" as we are using indexes that GRIB wasn't designed for.  Likewise
>the "edge2bufr" table contains some sequences.

I took a stab at decoding the GRIB messages in the two files you sent:

0407262006fa.prd.grb
0407262005ef.prd.grb

using McIDAS-XCD.  The McIDAS GRIB decoder did not decode grib messages
from either file even though it correctly recognized the messages.

A quick check of a decode attempt showed some strange things:

- the GRIB parameter table number is set to be 220 (decoder is expecting
  1, 2 or 3)

- the forecast time unit of the parameter in 0407262006fa.prd.grb is set
  to be 0 (zero; this is not supported by the XCD code)

I would have to dig deeper to see if these two things are contrary to
the GRIB standard, or if the McIDAS-XCD code is not complete enough
to support values as specified in the GRIB message.

>Have a nice trip.

Thanks, I had a very nice trip!

Cheers,

Tom

>------------------
>On Thu 04 Nov 2004 17:03, Unidata Support wrote:
>From: Micah Epps <address@hidden>
>
>>Organization: DRS Weather Systems, Inc.
>>Keywords: 200411031720.iA3HKjvV010975 McIDAS GRIB XCD
>
>Micah,
>
>>Our company builds weather radar systems and respective software.  A
>> customer wants our radar software to feed a McIDAS system.  We understand
>> that the GRIB file format will work.
>
>The McIDAS-XCD package contains a decoder that will convert GRIB
>messages to McIDAS GRID fields.  This package works for the GRIB
>messages (_not_ GRIB2) that are in NOAAPORT, and might well work with
>the ones that your system produces, but the only way to be sure is to
>test decoding them.
>
>>I would be interested in sending you samples of
>>our GRIB files to verify that they are McIDAS compatible.  How shall we
>>proceed with this?
>
>I am willing to see if the GRIB files can be decoded with no effort,
>but I must tell you that I am heading out on a business trip starting
>Saturday and will not return until the day before Thanksgiving.  It
>seems that I will most likely not have enough time to give your GRIB
>files a fair test before I leave, so you are looking at a three week
>wait until I return.  I am sorry that there is nothing I can do about
>this.
>
>>Best Regards,
>>Micah Epps
>>--
>>Micah T. Epps
>>Software Engineer
>>334.347.3478, ext. 228
>>DRS Weather Systems, Inc.
>>128 South Industrial Blvd.
>>Enterprise, AL 36330
>>GMT -0600

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>From address@hidden  Tue Nov 30 07:19:22 2004

Tom-

Thanks for looking into it.  Dave Santek has informed me that thought
McIDAS supports GRIB, it does so in a very specific way; GRIB is a very
broad format.  We have since agreed on a very simple data format
already supported by McIDAS.  Hopefully this will satisfy our
customers' requirements.

Thanks again for your effort.

Sincerely,

-Micah
-- 
Micah T. Epps
Software Engineer
334.347.3478, ext. 228
DRS Weather Systems, Inc.
128 South Industrial Blvd.
Enterprise, AL 36330
GMT -0600