Class Project: Lunar Radio TelescopeDue Date: 12 December 2006 (Tuesday)ECE 6390: Satellite Communications and Navigation SystemsGeorgia Institute of Technology1 IntroductionBecause visible light only accounts for a tiny portion of electromagnetic spectrum, radio astronomyis an extremely important research enterprize that allows scientists to see new, invisible parts ofthe universe. In a similar vein, radio astronomy likely provides the only pathway for discerning theexistence of extra-terrestrial intelligence in our universe. There is a growing problem with earthboundradio astronomy observatories, however. The phenomenal growth of wireless communications andnoise-generating devices has polluted the radio spectrum with increasing amounts of man-madeinterference. Even in frequency bands that have been traditionally reserved for radio astronomers,man-made noise is creeping into the spectrum and making it impossible to resolve the faint signaturesof distant radio-emitting bodies. Soon there will be no place on or around the earth that is possibleto study this beautiful and invisible part of outer space.There is one last chance for the radio astronomers, however. Earth has the incredible fortuneof having its one and only natural satellite, the unnaturally large moon, locked in synchronousrotation. That is, the moon completes one rotation and one revolution about the earth at preciselyequal periods. Thus, there is one side of the moon (the inappropriately named “dark side of themoon”) that is perpetually facing away from the earth, shielded from manmade noise. One idea forgreatly enhancing the prospects of radio astronomers is to build an astronomy on this far side of themoon and relay the collected radio data back to earth-based laboratories.NASA has contracted your private space consulting firm to design the radio frequency (RF) andcommunication system that will collect the radio astronomy data and relay it back to earth-basedresearchers. Your final design, to be unveiled to the world on Tuesday, 12 Decemb er 2006, will bejudged against designs from competing firms that will try to make the most reliable, low-cost, andfunctional radio observatory.2 Design DetailsThe goal is to build a radio observatory that makes continuous measurements of the spectrumbetween 1.000-4.000 GHz. This data must be relayed back to earth without loss through one ormore satellites in a communication network. The moon-based dish will have a diameter of 300m,an aperture efficiency of 0.90, and a receiver with TSY S= 20 K. It will be constructed in the craterDaedalus and will operate in a manner similar to the earth-based radio astronomical observatory atArecibo in Puerto Rico.You may choose the operating frequencies of the return data link to earth (avoid 1.40-1.43GHz, 4.9-5.0 GHz, 10.6-10.7 GHz, and 15.3-15.4 GHz, which would interfere with radio telescopeson the Earth.) In addition to your design of the overall system (spacecraft orbits, transponderdesigns, modulation type, multiple access, etc.), you must demonstrate the technical feasibility ofyour design by finding specifications on analog-to-digital converters, RF oscillators, and any otherspecialty electronics that would limit your implementation.Show that your design is cost-effective (total cost, including spacecraft ) by justifying all costestimates or assumptions. You may estimate the cost of putting satellites into high-earth orbits asbeing $150 M (including launch) plus 1$ M per transmitted watt of power (not EIRP). For eachcommunication link, there should be a chart in your report that lists transmit power, RF bandwidth,pulse shape/modulation scheme, symbol rate, bit rate, antenna gains, carrier frequency, estimatedCNR, and any other technical specifications important for understanding your design.3 DeliverablesYou must prepare a concise, well-written technical report detailing your design for the RF front endof the radio astronomy station on the moon as well as the relay network for sending the data backto earth. The report should be in html-format with all files submitted in-class on a CD or throughe-mail1. Your report will be graded on the following:• Completeness• Technical Writing• Technical Correctness• Professional Content• Research (cite all references)• ConcisenessI will offer +5% bonus points to superlative reports in the following categories:• Best Technical Writing• Most Thorough Technical Research• Creative Use of Web PresentationLate projects will not be accepted. I will likely post some of the unique solutions and high-qualityprojects to the web, unless the author requests otherwise.4 CreditsThanks to Prof. Paul Steffes for help with the formulation of this project.1e-mail submissions are strongly preferred; they must be ZIPped and are only possible for files less than 10