Investigations in the Area of High bit rate Data Transmitting Systems for Remote Sensing Satellites

Abstract

The quest for improving resolution of the imageries from remote sensing satellites to less than a newlinemeter is necessitating transmission of higher data rates starting from a few Megabits to newlineGigabits/second. As data rates are increasing, consideration of spectrum and channel bandwidth newlinehas become more stringent to conserve spectrum and to assure optimum data transmission newlinecapability. This led to migration to higher frequency bands and search for a wide variety of newlinetechniques viz., frequency re-use, use of spectrally efficient modulation and source coding. New newlinetechniques are continuously explored for transmitting the increasing data in the limited Radio newlineFrequency (RF) spectrum to provide a secured data transmission from satellites to the designated newlineground stations. newlineTransmitting systems are designed based on the Link estimates which help in understanding newlineabout the RF transmission power requirements, sizing of ground and onboard antenna systems, newlineconfiguring the ground and onboard systems for desired data quality. Often, spectrum newlinedistortions, loss of RF link, and increased bit errors are noticed in high bit rate data transmission newlinelinks of many Indian Remote Sensing (IRS) satellites. This work involves basic investigation of newlinethe high bit rate data transmission links to identify the causes for these effects including link newlineperformance degradation. Various parameters that effect RF performance of the high bit rate newlinedata transmission link are identified and their affect is studied to design a high bit rate data newlinetransmission system, with optimum utilization of the premium satellite power, for ensuring newlinereliable Space to Earth data link. Suitable satellite data transmission system configurations are newlinesuggested for high bit rate data transmission.transmission from satellites.