Title :
Reflectivity estimation for multibaseline interferometric radar imaging of layover extended sources
Author :
Lombardini, Fabrizio ; Montanari, Monica ; Gini, Fulvio
Author_Institution :
Dept. of "Ingegneria dell\´\´Informazione", Pisa Univ., Italy
fDate :
6/1/2003 12:00:00 AM
Abstract :
In recent years, there has been great interest in exploiting the advanced multibaseline operation of synthetic aperture radar interferometry (InSAR) for solving layover effects from complex orography, which can degrade both SAR and InSAR imagery of terrain radar reflectivity and height. In this work, the problem of retrieving radar reflectivity of layover areas is addressed. It is formulated as the problem of estimating a multicomponent sinusoidal signal corrupted by multiplicative complex correlated noise and additive white Gaussian noise. Application of nonparametric [e.g., Capon, amplitude and phase estimation filter (APES)], parametric [least squares, modern parametric RELAXation spectral estimator (RELAX)], and hybrid spectral estimators for amplitude estimation is investigated for a multilook scenario. In particular, the multilook extensions of RELAX and APES are applied to the interferometric problem. Performance analysis is investigated through a Cramer-Rao lower bound calculation and Monte Carlo simulation. The method of least squares, coupled with Capon´s approach to spatial frequency estimation, multilook APES, and multilook RELAX turn out to provide accurate reflectivity estimates for undistorted multibaseline image formation of layover areas.
Keywords :
AWGN; Monte Carlo methods; amplitude estimation; radar imaging; radiowave interferometry; synthetic aperture radar; APES; Capon´s approach; InSAR; Monte Carlo simulation; RELAX; SAR; additive white Gaussian noise; amplitude estimation; complex orography; component sinusoidal signal; hybrid spectral estimators; layover extended sources; multibaseline interferometric radar imaging; multibaseline operation; multiplicative complex correlated noise; nonparametric estimators; parametric estimators; reflectivity estimation; spatial frequency estimation; synthetic aperture radar interferometry; terrain height; undistorted multibaseline image formation; Additive white noise; Amplitude estimation; Degradation; Frequency estimation; Least squares approximation; Phase estimation; Radar imaging; Reflectivity; Synthetic aperture radar; Synthetic aperture radar interferometry;
Journal_Title :
Signal Processing, IEEE Transactions on
DOI :
10.1109/TSP.2003.811239