[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Oscar 0

On Thu, 22 Jun 2000, Scott E. Olitsky wrote:

> It would be interesting to do the calculations on this.  The path loss for
> EME is somewhere on the order of -250 dB.  Much of this loss is related to
> the fact that the moon is a very poor reflector and only 6.5% of the signal
> that hits the moon is returned to us.  A transponder should would return
> more than that so the path loss would be significantly less.

That is forgetting one thing.  ALthough the moon is only 6% effective as a
reflector, its Antenna is several thousand square miles.  Your antennas on
the moon will only be a few feet, and so they will receive millionths of
the transmitted power from earth.  If I were to guess, I would say that it
will take a 13 dB (long 2m yagi) and 1000 watts to be heard on a moon
receiver if it only has an omni antenna (rover).  But the rover then has
to also have 1000 watts to get back, OR a larger antenna.

Good luck

Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org