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Hi Richard,

re: which version of McIDAS are you looking at using
> Not entirely sure but since we do not currently use the McIDAS
> legacy software I suppose we'd want the newer version. I am
> downloading it now for a look.

Very good.  Code was added to McIDAS-V to be able to use METEOSAT
imagery in its wavelet compressed form.  This may be just what you
are looking for.

re: which bands were you interested in resolution for?

> I was talking about the lower resolution channels. I have read that
> they have a 3km resolution but out here in Qatar, right on the edge
> of the image, the resolution when projected to  lat/lon seems a lot
> lower (even as low as 6-7km). Since many authors report 3km resolution
> regardless of location I was wondering if I am missing something.

People typically quote the resolution at the sub-satellite point.  I
referred to this as the nominal resolution: 3 km for the IR channels
and 1 km for the high resolution VIS channel.

You are correct in your comment that the resolution at a specific
location will be worse than that directly under the satellite.  For
instance, I just created a band 9 (10.8 um) image sector from METEOSAT
10 centered on Qatar (25N, 51E), and I see that the resolution at
the center of this sector (which will be at 25N, 51E) is 4.62x6.39 km.

re: Spatial resolution can not be improved from its original form.

> Thanks. We were wondering if the high-res channel is somehow used
> (fused?) to simulate higher res

No, it is not.

> It seems that  EUMETSAT provide images in 'native' format (.nat
> extension).

I am not familiar with the format of files with .nat extension.

The wavelet compressed form I referred to earlier is the format
that would be on disk as a result of receipt/procesing by a EUMETSAT
satellite ingestor (the format of the data in EUMETCAST is (or
at least was) wavelet compressed).

> There seems to be few software that read this (we tried
> ENVI and ArcGIS which didn't read the image and ultimately Quantum
> GIS that did though clunkily (through functionality of GDAL libraries)).

Hmm... I wouldn't imagine that Quantum GIS would know about the
wavelet compressed format used in EUMETCAST broadcast, but I could
be wrong.

> Given the hassles I have had to make sense of this data I think there
> is a real need for something like McIDAS

> I am looking forward to downloading McIDAS and trying it out.

I assume from the comment made at the beginning of this email that you
are in the process of testing out use of McIDAS-V (which you would have
downloaded from UW/SSEC, not Unidata).

> Thanks again for your prompt and informative reply. You have really helped us.

No worries.


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Ticket Details
Ticket ID: HCT-951994
Department: Support McIDAS
Priority: Normal
Status: Closed

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