[amsat-bb] RAFT radar Detection and Southern Ground Stations

[Robert Bruninga]

The RAFT Radar Transponder has been detected.  See plot:
http://www.ew.usna.edu/~bruninga/craft/XP217-PE1ITR4feb07.JPG

Although the 4 milliwatt RAFT Radar Fence oscillator was
designed to be heard by the collosal 2 mile long 30 dB gain
receive antenna of the Radar Fence across the southern USA,
PE1ITR was able to detect the oscillator on his own ground
station.

We are still welcoming GOOD OSCAR class AMSAT stations near the
RADAR fence across the southern USA (Arizona through Texas to
Georgia) who have good 2 meter beams, to command on the RAFT
Radar fence transponder so that we can make our first Radar
Fence detection.  RAFT requires a good 2m beam station to
operate it.

The primary objective is for RAFT's radar xponder to HEAR the
radar fence as it flies through it.  Since this is not
detectible here at USNA due to our latitude, we are dependent on
volunteer ground stations in the southern USA to activate the
RAFT transponder at precisely the correct time to make this
detection.  There is only one good pass per station in the
evening hours and so it is slow going.

But the detection above, gives great confidence in the primary
objective.. 

For more on RAFT's radar Fence Transponder which is a model for
future small satellites to be able to detect their own passage
through the fence, see the main RAFT web page about half way
down the page:
http://www.ew.usna.edu/~bruninga/raft.html

To see the overall ANDE-RAFT and MARScom operations page see:
http://www.ew.usna.edu/~bruninga/ande-raft-ops.html

And we still need good ANDE data from the Southern Hemisphere so
we can detect the spin rate.  Right now, ANDE is in the dark in
the Northern Hemisphere.  We need data from the Southern
Hemisphere.  ANDE only wakes 2 seconds every 16 seconds to
listen for activity.  IF it hears any packets, then it will stay
awake for the next minute.  While it is awake, it can be used
just like PCSAT-1 as an APRS digipeater by all users.  And while
it is awake, we will also be able to hear telemetry which is
what we need.

Hopefully all the 145.825 Igates are listening.

Bob, WB4APR
USNA Satellite Lab