A RANGE-RATE AND RANGE MEASUREMENT MODULE FOR ONBOARD APPLICATION IN AEROSPACE VEHICLES

摘要

A module for onboard autonomous measurement of range- rate and range of aerospace vehicles for advanced manned/unmanned space missions, based on the determination of Doppler shift in frequency of one-way uplink continuous wave stable transmissions from ground is disclosed, in which 70 ± 0.1 MHz band IF signals converted from S Band (2200 MHz) signals transmitted from ground are digitised by bandpass sampling at the rate of 436.875 KHz to accommodate positive as well as negative Doppler shift in frequency, and the range-rate and range are determined in a DSP processor by implementing the advanced Fast Fourier Transform and Zoom Analysis techniques to determine range-rate with expected errors less than 15 cm/sec and resolution up to 5.68 cm/ sec.