What is EME?
Earth-Moon-Earth, EME or Moonbounce is a form of radio communication propagation used by radio amateurs and others to effect global communications on frequencies above 50 MHz.
In not so many years past, in order to work stations via Moon Bounch {EME} required a huge level of commitment and was not for the faint of heart. A large investment that was beyond the capability of most Amateurs budget, space and time was required. Massive antenna arrays, very high power of 1,000 watts or greater, High gain, low noise floor mast mounted pre-amps, massive Azimuth and elevation rotors and more patience then most of the population has. Today Moonbounce propagation still presents a number of significant technical and operating challenges, but provides a real sense of achievement and enjoyment when a contact has been successfully achieved.
Using VHF and UHF amateur radio bands, along with relatively high powers, high gain antennas and sensitive receivers, it is not a mode for all, but with today’s technology it is a mode that is within the reach of a large number of amateur radio stations.
Moonbounce basics
The basis of operation of Moonbounce or EME, Earth-Moon-Earth is the use of the Moon as a passive reflector. In view of the very large distances involved and the fact that the Moon's surface is a poor reflector the path losses are colossal, but nevertheless it is still a form of communication that is theoretically possible to use, and one that many radio amateurs regularly use.
Concept of Moonbounce EME propagation
With radio signals being very low, it is found that galactic noise becomes a significant factor. This noise emanates from a variety of sources in the galaxy - planets, stars, etc. emit noise throughout the radio spectrum, and EME systems are very sensitive and will be able to hear this noise. The level of noise is not constant across the sky and this means that some times the sky around the Moon can be very noisy and at other times it can be much quieter.
It is found that sky noise is normally worst when the Moon is crossing the galactic plane (i.e. the Moon appears in the Milky Way) and this occurs twice each month. Fortunately software used for amateur radio EME Moonbounce indicates this and this helps choose the optimum times for any activity.
Equipment considerations for EME Moonbounce
To overcome the losses and enable amateur radio radio communications to be established using Moonbounce, very high radio transmitter powers, directive antennas and very sensitive receivers are required.
With the distance of the Moon from the Earth being between 360 and 405 thousand kilometersand its diameter being 3475 kilometres it subtends an angle of only 0.52 degree to observers on the Earth. In order to illuminate the Moon with little wasted power either side, enormously directive antennas are required. Also these antennas must be completely steerable to be able to track the steadily changing position of the Moon.
Earth-Moon-Earth, EME or Moonbounce is a form of radio communication propagation used by radio amateurs and others to effect global communications on frequencies above 50 MHz.
In not so many years past, in order to work stations via Moon Bounch {EME} required a huge level of commitment and was not for the faint of heart. A large investment that was beyond the capability of most Amateurs budget, space and time was required. Massive antenna arrays, very high power of 1,000 watts or greater, High gain, low noise floor mast mounted pre-amps, massive Azimuth and elevation rotors and more patience then most of the population has. Today Moonbounce propagation still presents a number of significant technical and operating challenges, but provides a real sense of achievement and enjoyment when a contact has been successfully achieved.
Using VHF and UHF amateur radio bands, along with relatively high powers, high gain antennas and sensitive receivers, it is not a mode for all, but with today’s technology it is a mode that is within the reach of a large number of amateur radio stations.
Moonbounce basics
The basis of operation of Moonbounce or EME, Earth-Moon-Earth is the use of the Moon as a passive reflector. In view of the very large distances involved and the fact that the Moon's surface is a poor reflector the path losses are colossal, but nevertheless it is still a form of communication that is theoretically possible to use, and one that many radio amateurs regularly use.
Concept of Moonbounce EME propagation
With radio signals being very low, it is found that galactic noise becomes a significant factor. This noise emanates from a variety of sources in the galaxy - planets, stars, etc. emit noise throughout the radio spectrum, and EME systems are very sensitive and will be able to hear this noise. The level of noise is not constant across the sky and this means that some times the sky around the Moon can be very noisy and at other times it can be much quieter.
It is found that sky noise is normally worst when the Moon is crossing the galactic plane (i.e. the Moon appears in the Milky Way) and this occurs twice each month. Fortunately software used for amateur radio EME Moonbounce indicates this and this helps choose the optimum times for any activity.
Equipment considerations for EME Moonbounce
To overcome the losses and enable amateur radio radio communications to be established using Moonbounce, very high radio transmitter powers, directive antennas and very sensitive receivers are required.
With the distance of the Moon from the Earth being between 360 and 405 thousand kilometersand its diameter being 3475 kilometres it subtends an angle of only 0.52 degree to observers on the Earth. In order to illuminate the Moon with little wasted power either side, enormously directive antennas are required. Also these antennas must be completely steerable to be able to track the steadily changing position of the Moon.
EME Links to help you get started in this exciting area of the hobby.
Bouncing signals off the Moon has always been considered as one of the most difficult of the amateur radio disciplines. Traditionally Moonbounce as it is known was practised by amateurs who are the most accomplished engineers as well as operators but recent developments have now made it more accessible than ever before. Get started in EME sets out to explain what you need to know and how to get started in this captivating area of amateur radio operation.EME Beacon
1296.000 ON0EME
400 Watts on auto tracking 12ft dish
How To Get Started On EME
http://www.g1ogy.com/www.n1bug.net/operate/emebasic.html
Small Station EME on 70cm and 23cm, using JT44/65.
http://www.nitehawk.com/rasmit/JT44/Jt44.pdf
Small Station EME.
https://tcf.pages.tcnj.edu/files/2013/12/SMALLSTATIONEME.pdf
Small Station 1st contact on EME
https://www.youtube.com/watch?v=nfrPwdmmky4