20030512: GMS raw to VISR

>From: Anthony James Wimmers <address@hidden>
>Organization: UVa
>Keywords: 200305130226.h4D2QX7U001210 McIDAS GMS IMGCOPY STYPE=VISR

Hi Tony,

>Is there any known way to convert a GMS-5 (raw calibration)
>to the VISR calibration?

I was first going to suggest the STYPE=VISR option of IMGCOPY:

C ?    STYpe=VISR | reduces 2-byte data to 1-byte brightness data; not valid
C ?                 with BAND=ALL or SIZE=ALL

but the output from IMGLIST you include below shows that the data
is already 1 byte.

>I have a batch file that works fine
>with GOES-10 and GOES-8 images, but has problems with the
>GMS-5 imagery because of the calibration.

What do you do in your BATCH file?

>At the very least, I need a conversion chart for raw
>calibration brightness values and brightness temperatures.
>Can you tell me where to find that?

The GMS calibration module kbxgms.dlm has this information.  If
your image is viable, then IMGPROBE can be used to list out
values from the image in user-specified units.  You come up
with a raw to brightness correspondence by listing out values
first in raw and then in brightness for the same box.

What does an IMGPROBE of your image show for the valid units for
the image?  If brightness is not one of the values, then could
you provide me with the image so I can take a look?

>Thanks!
>
>Example:
>
>Image file directory listing for:LA
> Pos Satellite/         Date       Time      Center      Res (km)
>Image_Size
>     sensor                                 Lat  Lon    Lat   Lon
> --- -------------  ------------  --------  ---- ----  ----- -----
>------------
>8101  GMS-5          3 MAY 02123  12:32:00    35 -140
>    Band: 4   6.8 um Water vapor detection              6.73  5.15  1048 x
>2292
>     proj:    0 created: 2002124  92023  memo: gms data in real time
>     type:GMS      cal type:RAW
>     offsets:  data=    9984 navigation=  256 calibration= 2816 auxillary=
>0
>     doc length:   0   cal length:   0   lev length:   0 PREFIX=   0
>     valcod:          0 zcor:  1 avg-smp: N
>     start yyddd: 2002123  start time:123222  start scan:    0
>     lcor:  733  ecor:   -31  bytes per pixel: 1  ss: 83
>     Resolution Factors (base=1):   Line=    4.0   Element=    4.0
>IMGLIST: done

Tom