[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[McIDAS #VMB-838792]: Meteosat conversion

This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.

  • Subject: [McIDAS #VMB-838792]: Meteosat conversion
  • Date: Wed, 24 Nov 2010 09:02:23 -0700
Hi Bernie,

re:
> The original images were obtained from Eumetsat and were supposedly in
> McIDAS AREA format.  These were the images that NREL used to process
> with AXFORM.

OK.  EUMETSAT is well familiar with McIDAS AREA format, so I would imagine
that there is nothing amiss in the files you got from them.

re:
> The images are Meteosat Second Generation HRV (visible)
> images and are 248022432 bytes.

OK.  I assume you are aware that the MSG high resolution visible images
contain coverage below a certain latitude that moves westward throughout
the day (the coverage over Europe remains fixed while that over Africa
moves westward with the sun).

re:
> The file names are of the form:
> Mcidas_MSG1-SEVI-MSG15-0100-NA-20050106215743.HRV. The binary files
> created by AXFORM are 248020992 bytes.

OK, got it -- the images are large.

re:
> I am attaching a text file of
> the header information from one of the converted binary files, and a
> plot of raw satellite dn values as a function of longitude at 5.55 deg
> latitude.  It looks like longitude is scaled by 100. Everything east
> of 0 deg and south of about 24 deg N is zero. Puzzling.

Your observation fits with the high res vis scanning strategy on MSG.
I have attached a snapshot of what this looks like in practice.  The
attached JPEG image is the full HRV scan for November 24 (today) at
12UTC.  Notice the scan breaks at 25N latitude and 0 longitude.

Cheers,

Tom
--
****************************************************************************
Unidata User Support                                    UCAR Unidata Program
(303) 497-8642                                                 P.O. Box 3000
address@hidden                                   Boulder, CO 80307
----------------------------------------------------------------------------
Unidata HomePage                       http://www.unidata.ucar.edu
****************************************************************************


Ticket Details
===================
Ticket ID: VMB-838792
Department: Support McIDAS
Priority: Normal
Status: Closed

Attachment: MSG_HRV_20101124_1200.jpg
Description: JPEG image