[amsat-bb] APRS to Moon orbit?

[Robert Bruninga]

Here's a crazy idea for APRS to moon orbit (omni antenna).

Unless I did something wrong, I think an Oscar class long yagi, and 250W
amp and 1200 baud FM packet can be received out near the moon with 3 dB
margin?  A key factor is that the nearly 16 dB of assumed noise floor we
have here on the ground at VHF does not exist in deep space.  And VHF
gives the largest receive aperture for a crossed dipole on the spacecraft.

The omni UHF downlink is a bear.  But with quad UHF long yagis and a 100W
transmitter at the moon distance we still come up about 12 dB short.  Can
we make up for that with distributed processing gain from a minimum of 16
Oscar class ground stations all phased together with the internet and GPS
precise timing and a little software?

If we could, then we have APRS out to moon orbit, with the downlink
visible to all via the APRS internet system.  And in digipeating mode, we
have half-earth coverage half the time when the moon is up.

What did I do wrong?

Bob, Wb4APR