20030331: TDF to McIDAS

>From: "Sousounis, Peter" <address@hidden>
>Organization: WSI
>Keywords: 200303311910.h2VJAdB2018136 McIDAS TeraScan

Peter,

Sorry this took awhile to get to...

>I am interested in finding a program or programs to convert TeraScan files
>(TDF) to McIDAS files. I understand that there is a routine to convert TDF
>files to HDF files. Can you tell me what the status is of the effort to
>convert HDF to AREA files (see below from
>http://www.unidata.ucar.edu/staff/tom/user_20020314.html) ?Any help would be
>greatly appreciated.

Since the TeraScan TDF file format is a black box, and since one must
be licensed for TeraScan in order to have the necessary libraries to
link against for a direct TDF -> AREA converter, a different approach
was taken:  Darien Gallant decided to create a converter for the HDF
files that TeraScan can output.  This approach is useful, but has some
limitations, the most serious of which is the information put into the
HDF.  Instead of being able to dump raw counts, the HDF files contain
calibrated values like temperature for IR channels, and albedo for the
VIS channel.  The conversion utility then uses the inverse of the
"standard" McIDAS conversions to create a file of equivalent raw
values.  Comparisons of the IR channels (e.g., 10.7 thermal IR and 6.8
um Water Vapor) with imagery created by McIDAS ingestors shows very
good correlations.  The visible imagery, however, is markedly
different.  It has been my opinion that the major difference in the
reconstructed VIS is a result of filtering done on the TeraScan side to
create the HDF file of albedos.  Quite frankly, the reconstructed VIS
images look a LOT cleaner than the VIS images ingested directly into
McIDAS AREA format!

So, the question back to you is whether or not the code for doing the
reconstruction is what you need/want?  If yes, I will contact Darien to
see if he is willing to let you have his code (I consulted with him on
various aspects of his development, but the code is all his).  I have
to think that he will not be eager to support other's use of this code,
however.

Depending on what your objective is (i.e., how much you will be wanting
to do conversions), there may be a cheaper (in the long run) approach.
The AMRC group at SSEC has shown that one can tap the sync and data off
of a TeraScan receiver and feed it into a SSEC SDI ingestor.  You would
then have a direct GOES ingest system that can provide output in McIDAS
AREA format (through ADDE access to the holdings).  Information on the
cost of an SSEC SDI box can be found in the McIDAS User Group pages:

McIDAS Users' Group
http://www.ssec.wisc.edu/mug

Year 2003 MUG Fees
http://www.ssec.wisc.edu/mug/STD_CHG2003TOP.html

>UCAR/JOSS 
>*      TerraScan (tm) to AREA imagery converter (effort in progress and
>showing advances: conversion is not from TDF files directly, but, rather
>from HDF files created by TeraScan and GOES navigation information provided
>by SSEC) (Gallant, Yoksas)

Tom Yoksas

>From address@hidden Mon Apr  7 08:21:54 2003
>Cc: "Hutchinson, Todd" <address@hidden>,
   "Marshall, Steve" <address@hidden>
>Subject: RE: 20030331: TDF to McIDAS 

Tom,

Thanks for your reply. I will consult with some folks here at WSI to decide
how we should proceed.

Regards.

Peter

PS - Peter Neilley says hello.