[NLRS] EME anniversary (1946) -- "Birth of radio astronomy"

[Chris Elmquist]

On Thursday (01/10/2019 at 04:02PM +0000), Bill Davis via NLRS wrote:
> 
> 
> "Welcome to "On This Day ... in Space!" where we peer back in our archives to find historic moments in spaceflight and astronomy. So enjoy a blast from the past with Space.com's Hanneke Weitering to look back at what happened on this day in space!
>  On January 10, 1946, the U.S. Army bounced radar signals off of Earth's moon for the first time ever. Known as "Project Diana," this was the first experiment in radio astronomy.
> 
>  Researchers set up a large transmitter, receiver and antenna at a laboratory at the U.S. Army Signal Corps' Fort Monmouth in New Jersey and blasted short radio pulses in the direction of the moon. Then 2.5 seconds later, the reflected radio signals were detected. So it took 2.5 seconds for the radio waves to make the 477,000-mile round trip to and from the moon. 
> 
>  With this successful experiment, Project Diana marked the birth of radio astronomy.
> "


A couple other references,

https://web.archive.org/web/20131004022956/http://www.campevans.org/_CE/html/diamof.html

https://www.projectdiana-eme.com/

https://en.wikipedia.org/wiki/Project_Diana

	The military implications of Project Diana were also profound. It
	provided the first clear test of the continuous wave FM Doppler
	radar developed during World War II by Edwin Howard Armstrong,
	which, by greatly increasing the signal range over the pulse radar
	then in use, enabled detection and tracking of potential inbound
	threats from intercontinental supersonic aircraft during the Cold
	War.[citation needed] It also demonstrated the feasibility of
	using the Moon as a passive reflector to transmit radio signals
	from one point on the Earth to the other, around the curve of the
	Earth. This Earth-Moon-Earth (EME) or "moonbounce" path has been
	used in a few communication systems. One of the first was the
	secret US military espionage PAMOR (Passive Moon Relay) program
	in 1950, which sought to eavesdrop on Soviet Russian military
	radio communication by picking up stray signals reflected from
	the Moon. The return signals were extremely faint, and the US
	began secret construction of the largest parabolic antenna in
	the world at Sugar Grove, West Virginia, until the project was
	abandoned in 1962 as too expensive. A more successful spinoff
	was the US Navy Communication Moon Relay or Operation Moonbounce
	communication system, which used the EME path for US military
	communication. In January, 1960 the system was inaugurated with
	a lunar relay link between Hawaii and Washington DC. Moonbounce
	communication was abandoned by the military with the advent of
	communications satellites in the early 1960s. Since then it has
	been used by amateur radio operators.

-- 
Chris Elmquist