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[aprssig] Trackers from Heaven?

Robert Bruninga bruninga at usna.edu
Thu Sep 13 00:19:47 UTC 2007


No, 0000 UTC is 8 PM EDT or 7 PM EST.

Good luck.  I never went looking, be nice to hear if anyone
finds one.
Bob
 
> Bob, is that AM & PM EST?

> -----Original Message-----
> Sent: Monday, July 30, 2007 11:36 AM
> Subject: [aprssig] Trackers from Heaven?
> 
> Someone just walked into my office with a NWS Radiosonde they 
> found in a
> field.  Talk about TRACKERS from HEAVEN...
> 
> The sign on the side says what it is and that it is of NO
FURTHER USE.
> So therefore its now his.  We opened it up and noticed a GPS
patch
> antenna and on the other side of the board was a pair of GPS
chips in
> 1.2" square cans.  Also there was anotehr can for the RF 
> transmitter and
> a 4 position dip switch and a frequency table.
> 
> We hooked up a 9v power supply across the dead battery and it 
> sprang to
> life.  Could just barely see it on a spectrum analyzer.  RF 
> power output
> is probably about 10 milliwatts or less.  Looked up the
battery and it
> appears the battery life is designed for about 6 hours.
> 
> 200 of these are launched every day at 0000 and 1200 UTC by
the WX
> service and they all fall into someone's backyard every 
> day...  Using HT
> Dfing techniques, it should be easy to find these things
before the 6
> hours is up..
> 
> Of course the telemetry format is not APRS, in fact, I think
the GPS
> chip set only recovers GPS doppler rates and sends those to
the ground
> for further processing???  but it would be fun for someone to
write  a
> decoder.  Then all we have to do is HACK the RF oscillator to
get it
> onto a HAM band and we have a continuous source of GPS
trackers for
> throw-away events.
> 
> I didn't have time to take photos, before the person had to
leave, but
> having had so much fun chasing the APRS balloon last week, I 
> now realize
> that you can chase balloons every day if you simply tune to
one of the
> frequenceis below, about 3 hours after the NWS launches them 
> at the same
> time every day..
> 
> 400.250
> 400.625
> 401.000
> 401.375
> 401.750
> 402.125
> 402.500
> 402.875
> 403.250
> 403.625
> 404.000
> 404.375
> 404.750
> 405.125
> 405.500
> 405.875
> 
> Lets see, 1200 and 0000 UTC is 8 AM and PM, and about perfect
for a
> quick ballooon chase.  Now to find out our local launch
site...
> 
> Bob, Wb4APR
> 
> 
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