Time-reversal approach for buried point scatterer detection using a low frequency SAR

Abstract

Time-reversal technique is more often applied in ultrawideband remote sensing. Its use is limited to the media in which the wave equations invariance condition is satisfied, i.e. a lossless and non-dispersion media. However, the loss (conductive) and dispersive media often occur in nature and are the subject of increasing attention. An example of such media is the soil, and its subsurface layered structure, which is subject of an investigation in a number of applications, for example: archaeological, environmental and civil engineering and security - detection of mines and unexploded ordnance. The motivation of this work is to apply the time-reversal technique of high resolution SAR imaging of subsurface soil. Firstly, on the basis of real soil geological database SPADE/2 the 3D model of soil was created as a cascade connection of thin and planar layers with a height d = 0.5 cm. Secondly, simulation for SAR Stripmap geometry were performed. Time-reversal operation on backscattered echo (from Forward probing) and TR probing were execute consecutively after Forward Probing an individual SAR platform position. Results for the three point scatterer, located at the different depth and at the different position along synthetic aperture, are presented, in detail, for closed point approach along aperture.