| 摘要 |
A synthetic aperture radar system (SAR) having a range correlator (10) is provided with a hybrid azimuth correlator (12) for correlation utilizing a block-pipelined Fast Fourier Transform (12a) having a predetermined FFT transform size with delay elements (Z) for so delaying SAR range correlated data as to embed in the Fourier transform operation a corner-turning function as the range correlated SAR data is converted from the time domain to a frequency domain. A transversal filter (12b) connected to receive the SAR data in the frequency domain, and from a generator (14b) a range migration compensation function, D, to a programmable shift register (30) for accurate range migration compensation; weights, Wi, to multipliers (35-38) for interpolation, and an azimuth reference function, phi j, in the frequency domain to a multiplier 42 for correlation of the SAR data. Following the transversal filter is a block-pipelined inverse FFT (12c) used to restore azimuth correlated data in the frequency domain to the time domain for imaging. The FFT transform size is selected to accommodate the different SAR azimuth aperture lengths, number of looks and prefiltering requirements.
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