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

>From: "Robert Mullenax" <address@hidden>
>Organization: NMSU/NSBF
>Keywords: 200204102048.g3AKmta26322 McIDAS IMGREMAP

Robert,

>Here is the result on the original image.  I did an IMGCHA MYDATA/IMAGES.67
>SS=70 BAND=4 before I did this.  I admit I am not totally familiar
>with IMGCHA:

OK, this is the kind of thing that I would have recommended.  Read on...

>LWU LIST AREA0067 0 64
>       0.          0           4 HEX:        0        4 ASCII:
>       2.         70       96001 HEX:       46    17701 ASCII:    F   w
>       4.          0         269 HEX:        0      10D ASCII:
>       6.       9681           1 HEX:     25D1        1 ASCII:   %
>       8.        480         640 HEX:      1E0      280 ASCII:
>      10.          1           1 HEX:        1        1 ASCII:
>      12.          1           1 HEX:        1        1 ASCII:
>      14.          0           0 HEX:        0        0 ASCII:
>      16.     102105      215250 HEX:    18ED9    348D2 ASCII:        H
>      18.          8           0 HEX:        8        0 ASCII:
>      20.          0           0 HEX:        0        0 ASCII:
>      22.          0           0 HEX:        0        0 ASCII:
>      24.  538976288   538976288 HEX: 20202020 20202020 ASCII:
>      26.  538976288   538976288 HEX: 20202020 20202020 ASCII:
>      28.  538976288   538976288 HEX: 20202020 20202020 ASCII:
>      30.  538976288   538976288 HEX: 20202020 20202020 ASCII:
>      32.         67        1280 HEX:       43      500 ASCII:    C
>      34.        256           0 HEX:      100        0 ASCII:
>      36.          0           0 HEX:        0        0 ASCII:
>      38.          0           0 HEX:        0        0 ASCII:
>      40.          0           0 HEX:        0        0 ASCII:
>      42.          0           0 HEX:        0        0 ASCII:
>      44.          0           0 HEX:        0        0 ASCII:
>      46.          0           0 HEX:        0        0 ASCII:
>      48.          0           0 HEX:        0        0 ASCII:
>      50.          0  1347568672 HEX:        0 50524420 ASCII:      PRD
>      52. 1112688980           0 HEX: 42524954        0 ASCII: BRIT
>      54.          0           0 HEX:        0        0 ASCII:
>      56.          0   538976288 HEX:        0 20202020 ASCII:
>      58.          1           0 HEX:        1        0 ASCII:
>      60.          0           0 HEX:        0        0 ASCII:
>      62.        768           3 HEX:      300        3 ASCII:
>      64. 1279348034           0 HEX: 4C414D42        0 ASCII: LAMB

OK, so word 51 (LWU output is zero-based) says that this is a PRoDuct.
That means that there will be a calibration block in the image that
should define the values of the pixels.  What we need to do now is
list out the section of the AREA file that has the calibration block:

LWU LIST AREA0067 704 720

>>From address@hidden Tue Apr 16 15:01:08 2002
>
>re: comments about calibration being different for GOES-East and MSAT
>
>Okay I understand this.  Ballpark numbers will be good enough in this
>case.

OK, super.  In this case, you could simply change the 'PRD ' word
in the header to 'VISR' and _I think_ then probe it to get back TEMPs
(since you already changed the Sensor Source to 70 and the band to 4).

>re: I wouldn't create two composites
>
>After looking at the two images I can see little difference as you say.

Actually, there could be a big difference at the extremes of the image.
The pixels from second image used in the IMGREMAP with MERGE=YES will
be the ones used in the composite.  As you approach the limb of the
image, the parallax will become greater and greater to the point that
the pixels contained in the composite will appear smeared.  This
effect will be minimized if the pixels used are not at the extremes
of either scan.  This may be why you commented that there doesn't
appear to be much difference in the two composites.

Tom

>From address@hidden Tue Apr 16 15:10:18 2002
>Subject: Re:20020416: using McIDAS to make METEOSAT/GOES-8 composite (cont.)
          
Okay, looks like the logjam has cleared in my mind..duh..

I see how to use IMGCHA properly.  I did an IMGCHA MYDATA... STYPE=VISR 
SS=70 BAND=4 CTYPE=BRIT and all is well now.  

Sorry for the barrage of e-mails.  

Thanks,
Robert

>From address@hidden Thu May  2 20:17:44 2002
>Subject: Re:20020416: using McIDAS to make METEOSAT/GOES-8 composite (cont.)
          
Tom,

I have done several informal comparisons between cloud top
temps on my GOES/METEOSAT composite and straight METEOSAT 
and the differences have only been 1-3 deg..which is certainly
tolerable.

Robert