Title :
Two-dimensional extrapolation and spectral estimation from arbitrary sampling configurations for SAR/ISAR imaging
Author :
Cabrera, Sergio D. ; Flores, Benjamin C. ; Rodriguez, Eulalio ; Thomas, Gabriel
Author_Institution :
Dept. of Electr. & Comput. Eng., Texas Univ., El Paso, TX, USA
fDate :
31 Oct-2 Nov 1994
Abstract :
The adaptive weighted norm extrapolation (AWNE) procedure of Cabrera and Parks (1991) is generalized to non-uniform one-dimensional (1-D) and two-dimensional (2-D) sampling configurations. This extrapolation procedure which is based on iterative modification of the frequency weighting function in minimum weighted norm extrapolation produces high frequency-domain resolution. The approach presented is derived for totally arbitrary sampling configurations to include those that appear in inverse synthetic aperture radar (ISAR) imaging of a rotating object. The resulting procedure produces estimates of signal samples on rectangular coordinates in the neighborhood of the given samples (interpolation) as well as beyond (extrapolation). When applied to SAR/ISAR imaging, the procedure produces a complex reflectivity image in the slant-range cross-range domain from the samples of the object´s Fourier transform, available at non-cartesian coordinate locations. Examples illustrate the performance of this interpolation/extrapolation procedure using samples of l-D and 2-D sums of complex sinusoids to simulate range profiles and images of a few point scatterers
Keywords :
Fourier transforms; estimation theory; extrapolation; frequency-domain analysis; image resolution; image sampling; iterative methods; radar imaging; spectral analysis; synthetic aperture radar; AWNE procedure; Fourier transform; ISAR imaging; SAR imaging; adaptive weighted norm extrapolation procedure; complex reflectivity image; complex sinusoids; extrapolation; frequency weighting function; frequency-domain resolution; inverse synthetic aperture radar imaging; iterative modification; noncartesian coordinate locations; nonuniform one-dimensional sampling; nonuniform two-dimensional sampling; point scatterers; range profiles; rectangular coordinates; rotating object; sampling configurations; slant-range cross-range domain; spectral estimation; Extrapolation; Fourier transforms; Frequency; High-resolution imaging; Interpolation; Inverse synthetic aperture radar; Reflectivity; Sampling methods; Signal resolution; Two dimensional displays;
Conference_Titel :
Signals, Systems and Computers, 1994. 1994 Conference Record of the Twenty-Eighth Asilomar Conference on
Conference_Location :
Pacific Grove, CA
Print_ISBN :
0-8186-6405-3
DOI :
10.1109/ACSSC.1994.471434
