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[Datastream #SXB-674928]: GOES East West imagery...

Hi Gilles,

re:
> I tried and tried again and it does not get any better.

Hmm...  I ran the procedure I outlined to you, and I demonstrated to
myself that the resolution of the either GOES-East or GOES-West was
much better than the resolution in the East/West composites.  I think that
the best thing will be for me to create a bundle that does what I am
suggesting so that you can run it yourself and see what I am seeing.

re:
> I started to wonder about the following:
> 
> Either on GOES East and GOES West, Colima state is really in the corner of
> the imagery (it is the reason I started to use the composite IR imagery).

I agree.

re:
> So, I wonder if it is not the angle from which the region of interest is
> seen that affects the resolution.

Yes, the angle will definitely affect the resolution.  The resolutions
listed in the McIDAS-X IMGLIST listings I sent in an earlier reply were
calculated for the pixel at the center of the sector in question.  The
result was (and still is) that using the East or West IR sector should
be better (higher resolution) than using the composite.

re:
> So I did the following:
> 
> I opened IDV with everything turned on again (well everything you
> mentioned), and I up-loaded first GOES West IR imagery alone and zoomed
> into the region of interest and captures the image.

OK.  Can you repeat this and include the IDV legend in the screen capture?
This will tell me if the image was loaded with adapted resolution.

re:
> Then I exit IDV and open it again uploading GOES East IR imagery alone and
> zoomed in on the same region...

OK.  Aside comment:  it would be simpler to open a second display and do
the GOES-East IR image load in it.

re:
> And same for the IR composite

Same comment as above:  just open a new display.

re:
> So each time IDV is reset, and this gives the attached pics (Colima State
> is the polygon right in the middle, ~N19.3 W103.7, looking a little
> different in each case due to projection)

OK.

> Obviously for my student's work we are interested in a larger region to see
> the development of MCSs or presence of TS/H,
> 
> But I wanted to explore the resolution of the satellite imagery one at a
> time
> 
> The pixels are not any better in the first two cases...

I will send a follow-up reply that includes screen captures that demonstate
the difference in resolution.

re:
> Am I correct thinking that it is the angle form which the region is seen
> that affects the resolution?

Yes, absolutely.  Both GOES-East and GOES-West are located over the equator.
The resolution quoted for IR channels for GOES is for a pixel at the
sub-satellite point (directly under the satellite).  The pixel resolution
will vary with distance away from the sub-satellite point.

re:
> Or something the way I am doing things is weird from your opinion

Something is definitely off since the composite image is also for an
idealized satellite located over the equator at 100W longitude, and
the resolution represented by its pixels will decrease as a function
of distance away from the sub-satellite point.

re:
> Thanks for your time and help

I will create some displays and send them to you in a separate reply.
Hopefully, I can get to this today.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: SXB-674928
Department: Support Datastream
Priority: Normal
Status: Closed