Investigation of airborne synthetic aperture radar parameters for buried target detection

Explosive hazards pose a threat to both civilians and warfighters in areas of current and past conflict. The U.S. Army Combat Capabilities Development Command (CCDC) has been exploring the use of an unmanned aerial vehicle (UAV)-mounted ultra-wideband (UWB) radar to image and detect obscured explosive hazards. In a stripmap modality, a synthetic aperture radar system travels in a straight line and takes measurements perpendicular to the platform’s direction of travel. The large angular diversity provided by the platform motion yields a fine cross-range resolution of the imaged scene. This problem space is being simulated in MATLAB to determine the feasibility of buried target detection and to identify the optimal parameters of operation on a UAV. Parameters such as platform height, incident angle, and bandwidth are investigated. It is shown that performance at different platform heights is determined by the dependence of the signal-to-noise ratio (SNR) on elevation. Furthermore, a minimum platform height is required to meet the minimum requirements of the time-bandwidth product for pulsed waveforms. An optimal transmit angle can be found by maximizing the target-to-clutter ratio (TCR). The target radar cross section (RCS) is taken from finite-difference time-domain (FDTD) models of targets of interest, and the clutter is simulated using the small perturbation method (SPM) for distributed clutter. Finally, the required resolution and bandwidth of the system are presented.