Automated algorithm for accurate doppler profile detection of MST radar signals considering removal of interference

Abstract

Identifying the accurate radar echo returns from the MST (Mesosphere-Stratosphere–Troposphere) region poses serious challenges, as the radar echo signals are of very low amplitude and hidden in noise. The process of extraction of the relevant signal information becomes intricate when the spectra sometimes are infected with interference signals of non-atmospheric origin. An automated algorithm is suggested for eliminating the interference bands in the Doppler spectra of MST radar signals. The process of removal of interference and de-noising of the radar echoes using soft thresholding techniques was achieved simultaneously. The algorithm was practically applied to interference contaminated MST radar data taken from National Atmospheric Research Laboratory (NARL), Gadanki, Tirupati and studied for removal of interference bands. It was found that the projected algorithm effectively removes multiple interference bands and also improves signal detectability. The power and Doppler values (moments) are estimated using FFT and HHT (Hilbert Huang Transform) and median Doppler is plotted on Doppler power spectrum and compared.