Hello David, Principally, the same as the Fyllingsdales BMEWS steerable phased array, yes ??.
We have some info on it on OBSERVATIONS. <http://www.observations.biz) 73 John. <la2...@amsat.org> ................................................................................................. > From: g0...@aol.com > Date: Fri, 3 Jul 2009 19:21:08 -0400 > To: kd6...@comcast.net; amsat-bb@amsat.org > Subject: [amsat-bb] The Moon is our Future / antennas > > > In a message dated 03/07/2009 20:46:44 GMT Standard Time, > kd6...@comcast.net writes: > > Building a prototype that works on Earth for project like this is only a > few percent of the effort required. Treating it as a radio club project > won't be effective as people need to sign up for a 5-year project. > > > Hi all. > > John is absolutely right in saying the complexity cannot be easily compared > to a terrestrial radio project. One other thing that stands an almost zero > chance of succeeding is a dish antenna that needs to point towards the > earth. If NASA and the ISS have trouble with moving parts on the solar array > you can imagine how much more difficult it would be on the moon. > > However, how about this. > The problem with the higher bands is power generation / path loss / antenna > gain. Any higher band like 1.2, 2.4 or 5.8G would need a high gain antenna > to offset the increased path loss. > > But, instead of a conventional steerable dish....with its unreliable moving > joints...How about an electrically steerable array of patches / dipoles / > or any other type of antenna element. > > But how to 'point' it? > > Well. actually I think Tom Clark provided the answer for that with his > proposal of a few years ago. The principle is this: If you have 2 arrays. > One > say on 5.6G uplink and one on 5.8G downlink, then the receiving array can > electrically look in different directions for a signal from the Earth. > Once the receiver has identified a signal and optimised the RX Antenna, the > information on the direction of the Earth i.e. the direction of the > strongest > incoming signal can be used to configure the transmit array which will > then beam a signal back to earth with high ERP. > > Directional, high gain, and no moving parts. > > Thanks > > David G0MRF > _______________________________________________ > Sent via amsat...@amsat.org. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb _________________________________________________________________ Drag n’ drop—Get easy photo sharing with Windows Live™ Photos. http://www.microsoft.com/windows/windowslive/products/photos.aspx _______________________________________________ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb