Impacts of imperfect receivers on complex correlation of 2D aperture synthesis microwave radiometer

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.