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.
Keywords: Synthetic aperture radar, Range Doppler algorithm, Wavelet
decomposition.
References
[1] Curlander, J.C., and McDonough, R.N.,“ Synthetic Aperture Radar: systems and signal processing”. New York, NY:
John Wiley & Sons, 1991.
[2] R.K.Raney, H.Runge, R.Bamler, G.Cumming,, and F.H.Wong., ‘Precision SAR Processing Using Chirp Scaling’,IEEE
Transactions on Geoscience, remote Sens., vol.32, no.4,pp.786-799 ,july. 1994
[3] R.Bamler, “Acomparison of range-doppler and wave number
domain SAR focusing algorithms”. IEEE Transactions on Geosci, remote Sens., vol.30, no.4,pp.706- 713,jul.1992
[4] Wang,J., and Liu,X., “SAR minimum-entropy autofocus using an adaptive – order Polynomial model”. IEEE Geoscience
and Remote Sensing Letters, 3, 4(oct,2006),512-516
[5] Wang,J., and Liu,X.,“Automatic correction of range migration in SAR Imaging”.IEEE Geoscience and Remote Sensing
Letters,7. 2(Apr,2010),256-260.
[6] Wang,J., and Liu,X., “ Velocity estimation of moving targets in SAR imaging”.IEEE Transactions on Aerospace and

Electronic System,50. 2(Apr,2014),1543-1548.