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Two-Dimensional Chirp-Z Transform Imaging Algorithm for General Airborne Bistatic High Squint SAR Data Focusing |
Ran Jin-he Li Xiu-he |
Electronic Engineering Institute, Hefei 230037, China |
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Abstract A two-dimensional Chirp-Z Transform (CZT) imaging algorithm for general bistatic high squint SAR is proposed. To deal with the serious range-azimuth cross coupling of echo signal in bistatic high squint SAR, Linear Range Walk Correction (LRWC) is performed in range frequency-azimuth time domain to correct the large LRW induced by the high squint model of platforms, and then the expression of a modified bistatic point target reference spectrum is derived. Reference Function Multiplication (RFM) is firstly performed to finish the bulk focusing. With the track decoupling formulas, phase terms of spectrum are decomposed into two independent phase terms as range-variant phase terms and azimuth-variant phase terms, and their space variances are eliminated by CZT respectively to get the focusing result. The simulation tests validate the effectiveness of the proposed imaging algorithm to focus the data of general airborne bistatic high squint SAR.
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Received: 28 October 2013
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Corresponding Authors:
Ran Jin-he
E-mail: jinhe_ran@163.com
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