[McIDAS #SDU-782063]: McIDAS - Restoring calibration after an IMGREMAP

Hi John,

re:
> Inquiry: I need to remap some band 4 (IR) GOES data before producing a
> NetCDF output with IMGCOPY.  The problem is that IMGREMAP destroys the
> IR temperature calibration data leaving me with only brit values for the
> imgcopy.  Is there a way to restore the original calibration data as read
> from the GINI file after the remap?
>
> > Actually, the GINI data does not have a calibration block associated with
> > it.  The calibration is known apriori, and the server handles the mapping
> > from brightness to temperature.  What you can do is add a calibration
> > to the remapped image using the PRDUTIL utility.  This is a bit tricky
> > to use, so it would be helpful for you to provide me with the AREA
> > file output from IMGREMAP so I can give you detailed instructions on the
> > steps needed to calibrate the image.

> Thanks for the help on this!  Here's a link to the area file:
> http://wxserver2.mos.org/jmstuff/GEIR_TEST.AREA
> 
> No urgent rush on this.

I just grabbed the GEIR_TEST.AREA file from your website and took a look
at it in McIDAS.  That this file has a valid calibration block can be
verified by examining it in McIDAS:

<all done as 'mcidas'>
- copy the image to the ~mcidas/workdata directory
- create an ADDE dataset whose content is just this image:

DSSERVE ADD MOS/AREA AREA DIRFILE=/home/mcidas/workdata/GEIR_TEST.AREA \"MOS 
TEST IMAGE

- load the image into the current frame:

IMGDISP MOS/AREA.1

- interrogate the image using IMGPROBE after moving the mouse cursor over an
  area within the image:

IMGPROBE MODE=N

Your listing should contain values for RAW, BRIT, and TEMP.  The inclusioun of
TEMP shows that McIDAS sees and understands the image's calibration block.

Another way to see the calibration block is to use the LWU utility:
LWU LIST GEIR_TEST.AREA 0 64

Word 62 (zero-based) from the listing shows that the calibration block begins
at byte 768 (word 192).  List the contents of the file from that point:

LWU LIST GEIR_TEST.AREA 192

Your listing should show TEMP as the first 4 bytes starting at word 192.

Were you, perhaps, thinking about a different image?




Cheers,

Tom
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Ticket Details
===================
Ticket ID: SDU-782063
Department: Support McIDAS
Priority: Normal
Status: Closed