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[McIDAS #VMY-981880]: GOES (GVAR V1) geometry

Hi Ioan,

re:
> I hope you're doing good

I'm well, thanks.  And you?

re:
> I'd like to bring up some detailed aspects of old GOES images for both,
> east and west.
> 
> I started to rebuild our GOES archives,  around 20 years of data, for both
> east and west.
> 
> My goal is to improve our database in terms of temporal and spatial
> accuracy.  I did some preliminary tests with GOES 13 and 15 and found out
> it is worth doing it. So I started the processing and when I had a detailed
> look at year 1999 I realized some of the images are wobbling.

Interesting.

re:
> The shifts are small, but  they are there and initially i suspected my
> software is doing something wrong. To my surprise i viewed the image with
> McIDAS V and the shift was there as well.

So, there was some sort of a navigation problem!?

re:
> Do you know, have you heard of GOES 08, 09, 10 having these kind of issues?

No, but, then again, we do not archive any data (other than what we refer
to as a real-time rolling archive), so we would not have occasion to look
back at historic GOES imagery.

re:
> I was under impression that one I use properly the navigation there would
> be no such issues.
> 
> Do you think McIDAS X is able to handle/fix these issues?

If the navigation problems are simple, then one might be able to implement
some corrections by tweaking some of the header information in McIDAS
AREA files.  If the navigation problem(s) are more subtle (like they
were for inter-band registration for GOES-13), their correction will
require modeling and quite a bit of effort to correct.  Since this is
the sort of thing that the SSEC Data Center does/is good at, I would
ask them if they implemented navigation corrections for historic
GOES imagery.

I guess the other thing you could do is retrieve some of the images
out of NOAA's CLASS system and then do a comparison with the images
you have saved.  The objective for doing this would be to see if
perhaps NOAA has implemented some sort of navigation correction for
historic GOES imagery.

re:
> As a picture is worth a thousand words... I attached a chunk of the image,
> south (mexican) California so you can have a brief look at what I am aiming
> at.

While it is hard to tell from the small areal coverage of the image you sent,
it looks like the navigation problem could be more subtle than a simple
N-S/E-W shift by one or more pixels.  If that really is the case, then
finding out how to implement a correction would likely involve a lot of
work.

re:
> All the best

How have you been finding the GOES-16 imagery (meaning is it working
nicely for you)?

Cheers,

Tom
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Ticket Details
===================
Ticket ID: VMY-981880
Department: Support McIDAS
Priority: Normal
Status: Closed
===================
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