Models and Signal Processing for Millimeter-Wave LFMCW SAR Imaging

In remote sensing applications, there is a special interest in lightweight, cost effective, and high resolution imaging sensors. The combination of linearly frequency modulated continuous wave (LFMCW) technology and synthetic aperture radar (SAR) technique can lead to such a sensor. As such, this paper concentrates on the models and signal processing of millimeter-wave (mmW) LFMCW SAR for high-resolution imaging, which includes two main parts. In the first part, the system models and useful relations for mmW LFMCW SAR imaging are provided, and an image formation algorithm that takes into account the special characteristics of CW (continuous wave) SAR is investigated. The second part focuses on the impact of LFMCW waveform errors on SAR imagery. The allowable magnitudes of phase error for each category are quantified, and an effective compensation technique for compensating possible frequency nonlinearity errors in LFMCW signals is presented. Thus the novel combination of mmW LFMCW and SAR can pave the way for the development of a small, lightweight, and high resolution imaging sensor.