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[McIDAS #UNQ-564030]: Meteosat5 brightness to temperature for color bar on McIDAS image display



Hi Arlene,

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re:
> I would like to include a color enhancement bar with temperatures on 
> Meteosat5 IR images.
> Do you have any information on the brightness to temperature conversions for 
> Meteosat 5?

I thought that the calibration for METEOSAT-5 IR was the same as for GOES/GVAR. 
 Given
the special lookup table provided by WNI, it is apparently not.

> I checked SSEC website and found the following information but I am not sure 
> where
> the values would be for a stretch table:
> 
> Data Files Included in McIDAS-XRD 2005:
> 
> Data File              Contributing Site        Description
> ---------              -----------------        ------------
> met5_BRITtoTEMP.wni   Weathernews, Inc.       MET5 brightness to temperature 
> conversion tables

Stretch tables can only be created as straight line segment mappings
between brightness and calibrated units.  I would think that one can also
do pointwise mappings since a point is the degenerative case of a straight
but I just learned that there are a maximum number of line segment that
can be specified in a stretch table (looks like 30).

So, the job at hand is creating a stretch table that maps the WNI temperature
values to brightness levels in 30 or less segments while preserving the
character of the T v B relationship.  The sequence will be something like:

SU INI MET5TEMP MSAT TEMP
SU MAKE MET5TEMP 328.907 328.907 0 0
 ...

I will plot up the T versus brit values and look for regions where straight
line segments can approximate the mapping that WNI provided.  If it looks
like the curve can be approximated by the limited number of straight line
segments, I will create a stretch table and pass it along.

> Thanks for your help.

No worries.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: UNQ-564030
Department: Support McIDAS
Priority: Normal
Status: Closed


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