20040811: navigation offset in GINI images?

>From: Tom Whittaker <address@hidden>
>Organization: UW/CIMSS
>Keywords: 200408112215.i7BMFaaW016132

Hi Tom,

It wasn't clear to me if your inquiry was directed at IDV folks, or if
you believe there to be a problem with the ADDE serving of GINI image
data.  I can tell you that I see routine occurrances of the navitation
in the GINI images being off by several pixels.  I don't know if this
is what you are referring to, or if you are questioning something in
the IDV.

Cheers,

Tom

>While checking out the IDV, I loaded an IR (3.9) image from gozer/unidata2 and
>  
>the same time GINIEAST IR from motherlode.  While the images look pretty much 
>the same, they are offset on a soft of NW-SE axis by a few pixels.
>
>Please see the little movie at:
>
>ftp://ftp.ssec.wisc.edu/pub/ssec/tomw/goes.mov
>
>I talked to Tom Rink, and he said it could be due to several things...but the 
>first question to ask is how the AREA files I read are created from the GINI 
>images -- looking for info on the navigation module that might be used, etc.
>
>Any info appreciated.
>
>There is a bundle (that I suppose will be good for another day) at the same 
>URL, but named "goes.xidv".
>
>I've looked at a couple of different times and find the same effect.
>
>Ideas?
>
>Thanks.
>
>tom
>
>-- 
>Tom Whittaker (address@hidden)
>University of Wisconsin-Madison
>Space Science and Engineering Center
>Cooperative Institute for Meteorological Satellite Studies
>Phone/VoiceMail: 608.262.2759
>
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>From address@hidden  Thu Aug 12 08:57:47 2004

Hi Tom!

I sent it to support because after Tom Rink and I talked it over, we decided 
the first thing to find out was how the ADDE AREA files are created from the 
GINI so that we could check the nav modules, before deciding whether or not it 
was related to the IDV or something else.

The effect I'm referring to is if you play that .mov file, which just 
ping-pongs between the two images, there is a several (3-4 or so) pixel NW->SE 
shift in the positioning of the clouds.

If you can't play the .mov, I took screen shots of the two images:

ftp://ftp.ssec.wisc.edu/pub/ssec/tomw/goes1.png
ftp://ftp.ssec.wisc.edu/pub/ssec/tomw/goes2.png

I guess if this is the kind of offsets you routinely see then I won't worry 
about it...so much ;-)

Hope all's well...

tom