, also known as moon bounce
, is a radio communications technique which relies on the propagation of radio waves from an Earth
-based transmitter directed via reflection from the surface of the Moon
back to an Earth-based receiver.
The use of the Moon as a passive communications satellite was proposed by Mr. W.J. Bray
of the British General Post Office
in 1940. It was calculated that with the available microwave transmission powers and low noise receivers, it would be possible to beam microwave signals up from Earth and reflect off the Moon. It was thought that at least one voice channel would be possible.
The "moon bounce" technique was developed by the United States Military
in the years after World War II
, with the first successful reception of echoes off the Moon being carried out at Fort Monmouth, New Jersey
on January 10, 1946 by John H. DeWitt
as part of Project Diana
. The project that followed led to more practical uses, including a link between the naval base at and headquarters in . In the days before , a link free of the vagaries of was revolutionary.
Later, the technique was used by non-military commercial users, and the first amateur detection of signals from the Moon took place in 1953
EME communications technical details
As the albedo
of the Moon is very low (maximally 12% but usually closer to 7%), and the path loss
over the 770,000 kilometre
return distance is... Read More