Physics
Scientific paper
Jun 1991
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1991spie.1417..550s&link_type=abstract
Proc. SPIE Vol. 1417, p. 550-561, Free-Space Laser Communication Technologies III, David L. Begley; Bernard D. Seery; Eds.
Physics
Scientific paper
Future manned missions to Mars, planned as part of NASA's Space Exploration Initiative (SEI), will require large amounts of communications link capacity in order to return high resolution video and scientific data from the Martian vicinity back to earth. Optical communications technology has the potential of supporting these high return data rates while offering significant savings in size, mass, and power over microwave systems. In this paper several different optical systems based on Nd:YAG, GaAs, and CO2 laser sources and employing both direct and heterodyne detection are analyzed in order to assess their feasibility in providing high data rate (10-1000 Mbps) Mars-to-Earth communications. Telescope sizes which minimize the required transmit laser power in the presence of random (Rayleigh distributed) pointing and tracking errors are determined for each optical implementation. It is shown that the RMS pointing/tracking accuracy is a critical parameter in defining the Mars-Earth optical link. Results of the analysis indicate that unless extremely small RMS pointing and tracking errors can be achieved ((sigma) < .2 (mu) rad), the most promising optical implementation appears to be the Nd:YAG laser using direct detection and a high order PPM modulation. For example, using a PPM order of Mequals64 and assuming an RMS pointing accuracy of (sigma) equals.2(mu) rad, a 100 Mbps Mars link can be implemented with a 40 cm telescope at Mars, a 5 W frequency-doubled (FD) Nd:YAG laser, and a 10 meter receive photon bucket at the earth.
No associations
LandOfFree
Comparison of optical technologies for a high-data-rate Mars link does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Comparison of optical technologies for a high-data-rate Mars link, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Comparison of optical technologies for a high-data-rate Mars link will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1278464