Abstract:

The combination of frequency-modulated continuous-wave (FMCW) technology and synthetic aperture radar (SAR) possesses several advantages, such as compact size, lightweight and less peak power, which provides great potential in the application of precision guidance. According to the downward movement for missile-borne SAR, a signal model of FMCW-SAR is proposed. To distinguish with traditional air-borne SAR, the effects of the residual quadratic phase term are introduced by the continuous motion under the condition of missileborne peculiarly, which affect the focusing effect in the range direction. Due to the above reasons, an imagingmethod based on subaperture processing is presented. The residual quadratic phase term is compensated in the 2-D frequency domain, which improves the focusing quality and the imaging effect. Implemented by fast Fourier transform (FFT) and product without involving interpolation, the method is high in computational efficiency. Simulation results of point targets are provided to validate the effectiveness of the proposed method.