[Scan-DC] Weather Satellite Images

[Steve Uhrig]

After a number of requests, I am copying a post I made to the Radio 
Imaging Group aka RIG list. Unedited.

APT = Automatic Picture Transmission. Weather satellites transmit 
strong signals at 137.xx megacycles. A special receiver and antenna 
is needed to copy them, but they're inexpensive. Software is 
freeware. Do a Google search on APT for more info.

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Hello all,

Here is a recent NOAA 17 image from my wife's station:

http://www.swssec.com/jpegs/noaa-17-12181544-msa.jpg

This is an image as delivered directly from the excellent WXTOIMG 
package. No manual manipulations or anything.  

It will be nothing special to you old pros, but we're proud of it as 
a novice effort, starting from scratch knowing nothing.  

My wife is a former U.S. Air Force meteorologist and really into 
weather. She lives for weather. We have professional weather station 
at our home with all the sensors, and I built the APT station for 
her. We climbed ladders and installed everything together. She 
operates it.  

Station is the Hamtronics receiver which practically built itself 
even with my tired old eyes, 10 meters of RG-8X to a Woodhouse 
antenna mounted a mast about 8 meters on top of a one story roof, in 
the middle of the woods in Maryland. Our buildings are in a small 
clearing in a depression, surrounded by tall trees. I had to clear 
and top trees to see the sky for satellite television and satellite 
Internet, and it's about 20 meters up to average ground level a 
kilometer in any direction. I have less than USD $300 in the entire 
station not counting the computer.  

Software, as mentioned, is WXTOIMG, generously supported by the 
author who several times immediately answered a lot of stupid email 
questions for an APT novice which resulted in perfect operation. 
Computer is a dinosaur Dell P2-300 megacycle machine upgraded from 
its original W95 to W98SE, with 256 megs of RAM but monstrous dual 
drives, formerly a server for my business. It takes it several 
minutes to build the images with all the enhancements my wife has 
selected, but we're not in a hurry and the machine was available. It 
is online constantly, and we update time automatically every hour 
with NIST, and Keplers manually once a day or when we think of it. I 
have one drive assigned specifically and exclusively for APT images, 
to simplify maintenance. An automatic Kepler update in the software 
for machines online all the time would be a nice touch.  

The video card and monitor on the machine are old and tired, but they 
still generate better images than a high resolution HP printer can 
produce. I'd love to put a fast machine loaded with RAM and a huge 
RAID array up for APT, but that's a dream I can't afford.  

We get excellent (in my opinion) images several times a day from the 
various birds. We have *never* gotten a usable image in months of 
activity from a Meteorsat so we have disabled that series.  

My wife is neither technical nor computer literate, but she has 
learned to go into Explorer, to the directory containing the images, 
and without opening them, delete any with small file sizes. Those 
have proven to be poor images. She's selected perhaps 5 enhancements 
of the countless number available which give her all the info she 
needs to know, and picks from those remaining after purging. Some she 
glances at, some she studies for a few minutes. She makes her 
analysis based on those images, input from our weather station, and 
her experience. It's very impressive how she, with absolute 
confidence, is far more accurate than the television weather people, 
even for other areas of the country where her family lives.  

Strange, as you would think the professionals on television would 
have access to the best tools and most accurate info, and would be 
the most experienced. They merely guess compared to my wife. If my 
wife would want to go into professional weather analysis and 
forecasting, all these others would be out of a job. She's a 
homemaker, though, with amateur tools purely for enjoyment. These APT 
images, though, were the last thing she needed to be able to read 
God's mind on weather.  

All I did was build the thing. My wife does all operation. She 
doesn't even do email and, not being computer savvy, I assigned 'her' 
computer in the bedroom with network privileges only to the web and 
printers, no access to other company machines in any of the buildings 
(my home and office are next door to each other and share resources). 
When we have visitors, her APT station impresses everyone and is a 
real icebreaker. Send them home with a printout of an image built 
before their eyes, and it's something they'll never forget!  

APT is a tool for my wife, not the end in itself. But it sure is fun 
for me!  

Thanks to Pete Smith whose call I do not remember, for infinite 
Elmering on APT as well as many other areas of hamming over the 
years, this list, and the author of WXTOIMG. I've been a ham since 
1970, and APT is about the most fun I've had in that time, and we did 
some crazy stuff when I was younger! Will have to wait for the 
statute of limitations to expire before discussing them!  

Steve WA3SWS		always learning  


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Steve Uhrig, SWS Security, Maryland (USA)
Mfrs of electronic surveillance equip
mailto:Steve@swssec.com  website http://www.swssec.com
tel +1+410-879-4035, fax +1+410-836-1190
"In God we trust, all others we monitor"
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