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[McIDAS #AME-140292]: TDF to AREA conversion

Hi Rogério,

re:
> Besides raw data from TeraScan we have the same data in other formats
> like netCDF, geotiff, binary, both calibrated and non calibrated, what I
> want to do is create a area file with any of these,

OK.  When you say 'binary', what exactly do you mean?

McIDAS-X has four routines that make the creation of a navigaged
and calibrated image in AREA format very easy for data in a binary
raster format:

MAKEAREA
MAKNAV
PRDUTIL
IMGCHA

I use these routines from time to time to convert imagery in
some picture format (e.g., GIF, JPG, PNG, etc.) into AREA files
so that they can be used in McIDAS and GEMPAK.  The problem is
that CPTEC is not licensed to use McIDAS-X, so it has no simple
way to take advantage of these routines.

re:
> Now I am studying the concepts and looking the better way to do this,
> when I saw the Daren's email I thought it would be easy, but now I
> discarded this and looking to convert a calibrated binary file

The process is simple in concept:

Add AREA header blocks to a raster of image values (this is what
MAKEAREA does); add navigation (this is what MAKNAV does; this
is a little tricky if the image is in its original satellite
projection; it is easy if the image has been remapped into
a known rectilinear projection); add calibration to the image
if needed (this is what PRDUTIL does; it is not needed if the
values are already calibrated so that there is the standard mapping
from brightness (1-byte value that ranges from 0 to 255) to
temperature (for IR images, that is)); and then update AREA file
header values to match the image (e.g., the date, time, sensor
source, etc.).  Darren followed this approach in his work, and
it worked nicely.  The only drawback was that for VIS images,
the raster that Darren worked with was an albedo representation
that had to be interpreted back into raw counts.  The other thing
was that Terascan (at least the version that Darren was using)
would apply some sort of conversion to the pixel values in the
raster, and this made the back conversion to raw counts suspect.
I compared images that Darren produced from his procedure to
images ingested directly from GOES and found that the procedure
worked acceptably well for infrared channels, but not so well
for visible images.

By the way, I must tell you that we avoided the need to convert
Terascan TDS imagery to McIDAS AREA format by licensing the
SDI package from UW/SSEC; splitting the signal coming from our
GOES receivers (we ingest GOES-East, GOES-West, and GOES-South
America) so that it feeds a machine setup for SDI while still
feeding a Terascan system.  The SDI system ingests the satellite
data and makes it available via McIDAS ADDE.  The end user then
then use an ADDE-enabled application (e.g., McIDAS-X, IDV, McIDAS-V)
to view/analyze/copy the images to a local file.  McIDAS-X can
do the copy so that the result is a McIDAS AREA file that we
then distribute in the UNIWISC (aka MCIDAS) IDD feed.  Waldenio
can fill you in on the IDD.

re:
> I read this doc:
> http://www.ssec.wisc.edu/mcidas/doc/misc_doc/area2.html, I'll try to
> create a c-file to write area file, until now I apreciate much your support

OK.  I will be glad to provide comments and help if you
run into areas where you need information.  I will also be
happy to compare images that you produce with ones created
from SDI-ingested data. I have done this before and provided
the results to Waldenio; this is what pointed out some problems
in the method then being used at CPTEC to create AREA files
that were distributed in the IDD-Brasil.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: AME-140292
Department: Support McIDAS
Priority: Normal
Status: Closed