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20020903: WXP unable to navigate Mollweide McIDAS AREA files (cont.)



>From: Daniel Vietor <address@hidden>
>Organization: Unisys
>Keywords: 200209010444.g814i3Z11395 Unidata-Wisconsin Mollweide

Hi Dan,

>The problem is with WXP not handling the Mollweide projection correctly. 
>Initially, the eres and lres parameters were set to 1 and I ignored 
>them.  When they changed to something like 16 or 24, my computation of 
>image resolution was incorrect.  This was an oversight on my end.
>
>I've since corrected this.  This might be causing the offset problem as 
>well but I don't have a problem image to test against.
>
>If someone can send me a Mollweide image from today so I can test it, I 
>would be a happy camper.

I out two Mollweide global IR composites in the pub/mcidas/data directory
of anonymous FTP on our FTP server, ftp.unidata.ucar.edu, for you
to grab:

File        yyyddd hhmmss  lcor  ecor lr er zr  lsiz  esiz z band
-----------+------ ------- ----- ---- -- -- --- ----- ---- - ----------------
AREA0100    102246  90000  9826  9681  1  1  1   350   640 1 ...4............
AREA0101    102246 120000  9826  9681  1  1  1   350   640 1 ...4............

Tom

>From address@hidden Tue Sep  3 14:44:38 2002
>CC: Jim Koermer <address@hidden>,
>   address@hidden, address@hidden,
>   "Benjamin J.  Cotton" <address@hidden>
>Subject: Re: 20020903: WXP unable to navigate Mollweide McIDAS AREA files 
>(cont.)

re: example Mollweide images

Thanks Tom!!

It was a simple fix.  There was a bug in the byte offset for the data in 
the Mollweide projection code.  For some strange reason, I used the 
navkey value to offset to the data section for everything except 
Mollweide images.  Weird... I must have been on drugs when I did that code.

There are 256 more bytes now in the header than before.  Without the 
navkey offset, I was 256 bytes off in reading into the image, thus the 
offset.

I'll put a new xsat out tonight.
-- 
________________________________________________________
Daniel Vietor               Mail: address@hidden
Unisys Corp                 Title: Engineer/Meteorologist
221 Gale Lane               Phone: 610-925-5206
Kennett Square PA 19348     Fax: 610-925-5215