Real-time validation of Indian Remote Sensing Satellite data down link chain performance and evaluation of online data analysis with BER measurement

摘要

Indian Remote Sensing Satellites transmit video data in X-band and telemetry data in S-band. Currently, there is no available mechanism to validate the data link chain performance from onboard satellite to ground station in real-time. In order to achieve the objective, a novel method of Real-time online Bit Error Rate (BER) measurement is formulated using Real-time BER validating system (RTBVS) for all IRS missions. The mechanism is designed, realized and implemented at Satellite ground station to evaluate total satellite data receive chain performance in real-time itself. The Real Time BER Validating System (RTBVS) is tested successfully and is made operational at Satellite Data Reception Station for IRS Satellite Series. The RTBVS design module consists of advanced high speed parallel frame synchronizer for high data rate satellites, flywheel logic for reliability and stability of good frame sync detection and synchronization, and display of BER on the fly in a suitable window logic of one million bits or selectable window greater than 10~6 bits. RTBVS aids in the routine offline checks viz., local loop checks conducted daily, far field bore sight radiation tests carried out at regular intervals at ground station, before acquisition of satellite for Ground station performance validation. Further, the required test PN data passes from satellite can be avoided by using RTBVS mechanism and that particular orbit can be released for real-time data reception. The routine off line checks validate the satellite data receive chain at ground station only, but the total data receive chain from onboard satellite to ground station can be established using the RTBVS system which displays the online BER reading and helps in evaluating the station performance.