[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

20020416: using McIDAS to make METEOSAT/GOES-8 composite (cont.)

This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.

  • Subject: 20020416: using McIDAS to make METEOSAT/GOES-8 composite (cont.)
  • Date: Tue, 16 Apr 2002 14:37:27 -0600
>From: "Robert Mullenax" <address@hidden>
>Organization: NMSU/NSBF
>Keywords: 200204102048.g3AKmta26322 McIDAS IMGREMAP

Robert,

>I used the IMGFLIT/IMGOPER method as you first suggested.   Wouldn't
>this explain why IMGPROBE doesn't produce TEMP values?

Yes.

>I ran
>GEWCOMP and IMGPROBE produces temps, GEWCOMP1 does not since
>it uses the maks technique?  Am I missing something here?

No, you are not missing anything.  Since I was not sure exactly how you
were creating your composites, I could not specifically tell you why
IMGPROBE was not able to return TEMP values.  This is the main reason I
asked for the output of:

LWU LIST AREA1234 0 64

This would tell me vital things like:

o the Sensor Source (SS) number
o the source type
o the calibration type

Now, once the composite is made, you could go back (in the same script)
and modify which ever value needs changing so that McIDAS views the
image as representing IR temperatures.

This doesn't change my comments about the calibration difference
between GOES and METEOSAT images.  The fact of the matter is that the
wavelength bands for each are slightly different, so the "calibrated"
IR temperatures will need to be viewed with suspicion.  Not that the
values won't be useful, mind you.  I am just trying to remind you (and
whoever uses the products down the road) of the science behind the
composite.

>The IMGFLIT/IMGOPER way produces a nicer image it seems,
>so I could use that for a web image and use the MERGE=YES method
>for use in GARP/McIDAS.

I don't see the need to create two different composite products,
since neither is inherently more correct than the other.  I would
create one using the IMGFILT/IMGOPER method and then adjust the
resultant image's header so that McIDAS will view it as a calibrated IR
image.  I would also run a little study to determine how different the
IR TEMPs that you get back from the composite are from the originals.
ASTAT would be a good routine to use for this investigation.

Later...

Tom

>From address@hidden Tue Apr 16 14:34:40 2002
>Subject: Re:20020415: using McIDAS to make METEOSAT/GOES-8 composite (cont.)
         
Okay, I went back and made the METEOSAT/GOES-8 composite using
the IMGREMAP MERGE=YES/IMGCOPY method (as used in GEWCOMP)
and I now get temp values..and it works in GARP as well.
That's actually very simple..I'll be compositing all over
the place now I guess.

Thanks,
Robert