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Along-track synthetic aperture radar interferometry (ATI) systems are used to detect a moving target and to estimate its radial velocity. A dual-channel (single-baseline) ATI system estimates the velocity ambiguously because there are many candidate velocities corresponding to the interferometric phase. To resolve the ambiguity of the estimates, a multichannel (multibaseline) ATI system is required. This letter proposes an efficient implementation technique of a multichannel ATI system by using a frequency-modulated continuous wave (FMCW) radar and an antenna arrangement method considering the inherent bi-static characteristic of FMCW radars. Also, a simple and robust radial velocity estimation algorithm suitable for the proposed system model is presented. The validity of the algorithm is confirmed with simulated ATI results. [ABSTRACT FROM AUTHOR]

Predistortion is used to compensate for a waveform or phase of a signal in advance. Although the signal that applies predistortion exhibits a nonideal shape at the baseband, it has an improved phase value after the signal is upconverted in the actual hardware. Most synthetic aperture radar studies have focused on image reconstruction using single-look complex or ground-range detected data. Other studies have only compensated for the peak phase error; thus, discontinuity remains. In this letter, we present a novel method to reduce the phase error by applying a polynomial regression predistortion based on system calibration. The new approach is formulated to minimize the overall pulse error in a signal generator. We use the second-order polynomial regression for the phase error and predistort the phase error using the regression value. The proposed method is applied to the baseband signal, which exhibits an improved phase value at the X-band (9.5–10 GHz). [ABSTRACT FROM AUTHOR]