Impacts of imperfect receivers on complex correlation of 2D aperture synthesis microwave radiometer
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摘要: 分析了矩形模型接收机频率响应的非理想性对综合孔径微波辐射计复相关值测量的影响.频率响应非理想性包括中心频率不一致、带宽不一致、群延迟不一致、本振相位不一致及带内波动,它们通过条纹洗涤函数产生复相关值测量误差.分析结果表明,群延迟不一致与本振相位不一致是产生复相关值相位误差的主要原因,中心频率不一致、带宽不一致、群延迟不一致及带内波动是产生复相关值幅度误差的主要原因,通过噪声注入法可校正这些幅度和相位误差,并用以上理论对北航二维综合孔径微波辐射计(BHU-2D)校正前后的误差进行了估计.Abstract: The impacts of receivers- rectangular frequency response imperfections on the complex correlation measurement of 2D aperture synthesis microwave radiometer were presented. These imperfections include center frequency imbalance, bandwidth imbalance, group delay imbalance, phase imbalance of local oscillator and in-band ripple. The analytical results show that the phase error of complex correlation mainly comes from group delay imbalance, phase imbalance of local oscillator, and that the amplitude error of complex correlation mainly comes from center frequency imbalance, bandwidth imbalance,group delay imbalance and in-band ripple. These amplitude errors and phase errors can be corrected by correlated noise injection. The complex correlation errors of Beihang university,2-dimensional(BHU-2D) aperture synthesis microwave radiometer before and after system correction were estimated.
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