Performance comparison between conventional and modified Range Doppler Algorithm in real time applications

Abstract

Synthetic aperture radar is an active remote sensing approach that transmits the known wavelength signal and measures the reflected wave from the scene. Moving target detection, imaging, and velocity estimation using raw data are active research fields with civilian and military applications. The synthetic aperture radar endures from the image degradation because of phase errors present in the received signal. These phase errors give rise to poor focus quality, spurious targets, loss of resolution and erroneous velocities. The primary objective of the paper is to produce a high-resolution image of the targets and the moving targets motion estimation present in the scene in the presence of phase errors. The modified range-Doppler algorithm performs the range migration correction and the focus filtering with the wavelet decomposition to improve the resolution of the target image. The parameters extracted from the range migration correction and azimuth filtering is used to estimate the moving target velocity. The modified RDA using Sym8 wavelet decomposition levels with AOPM for moving target velocity estimation of SAR image have the average percentage of accuracy is 1.99. This proposed RDA method gives the close approximation to the actual velocity value and also improves the focus quality of the target image when compared with the conventional RDA.