It's about 20 dB more path loss to the moon than to geosynchronous orbit. So if you need 5-10 watts of RF to a small dish for the geosynchronous satellite, you'd need 1000w to the same dish or a much larger dish to reach a transponder on the moon.
Not to mention the delay for a signal to the moon and back is 2.6 seconds compared to about 240 ms for a signal to and from a geosynchronous satellite.
73,
Paul, N8HM
On Sat, Nov 7, 2015 at 3:00 PM, Joe nss@mwt.net wrote:
oops I missed Now drop the same transponder on the moon,, and how much more is needed?
Joe WB9SBD Sig The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com
On 11/7/2015 1:57 PM, Joe wrote:
Can anyone here run a link budget for me?
I'm in an slight heated debate with some people, About how they have heard about the possible Geo synchronous bird coming up, and they are all wondering why don't "THEY" I like the "THEY" part, anyway why don't they just put it on the moon.
I gave them several reasons why a Geo bird is better,
1- It is there 24/7 where the moon is visible less than 50% of the day
2- the Geo bird doesn't move ( or extremely little) so set the antenna and forget it. Where the moon requires tracking programs and antennas that can move in AZ and EL
3- Useable "Window" The amount of the earths surface that can see either is soo close to the same why bother I bet a geo bird would be at least close to 90% of what the moon see's
4- And finally antennas and power required. The moon being soooo much farther away the amount of power needed each way has to be MUCH more. And thats what I was wondering say you had a nice decent transponder in Geo orbit. what power levels say ERP I guess is needed each way? then drop the same transponder and how much more erp each way will be needed to have the same level of contact quality?
Joe WB9SBD
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb