非線性CS算法的前斜視SAR成像
Nonlinear CS algorithms for forward-squint SAR imaging
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摘要: 針對(duì)SAR的前途斜視工作模式,該文建立了雷達(dá)信號(hào)的回波模型,詳細(xì)分析了回波信號(hào)的瞬時(shí)方位頻率和瞬時(shí)多普勒頻率及距離Chirp斜率對(duì)方位頻率的影響。然后結(jié)合經(jīng)典的CS算法,提出了一種基于前斜視的改進(jìn)CS算法,并利用該方法進(jìn)行了仿真試驗(yàn)。理論分析和仿真結(jié)果表明,該方法更符合斜視SAR的幾何關(guān)系,能有效地進(jìn)行距離壓縮、距離徒動(dòng)校正和方位聚焦,改善了成像質(zhì)量。
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關(guān)鍵詞:
- 合成孔徑雷達(dá);前斜視;CS算法;距離Chirp斜率
Abstract: Based on the forward-squint-looking SAR mode of SAR system, this paper gives the mathematical model of SAR echo signal, and carefully analyses the instantaneous azimuth frequency , the instantaneous Doppler frequency component of the azimuth frequency and the impact of range chirp on azimuth frequency, then combining with the common chirp scal-ing algorithms, proposes an improved chirp scaling algorithm for forward-squint-looking SAR, imaging, and takes the simulated test with the algorithm. The results of theory and simula-tion show that the way is more reasonable for forward-squint-looking SAR geometric relation and can effectively complete range cell migration correction, range compression and azimuth focusing, and improve images quality. -
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