DIFFRACTION TOMOGRAPHY FOR MULTI-MONOSTATIC GROUND-PENETRATING RADAR IMAGING

A generalized diffraction tomographic (DT) algorithm is derived for su bsurface imaging from multifrequency multi-monostatic ground penetrati ng radar (GPR) data. The algorithm is based on the Born approximation for vector electromagnetic scattering and incorporates realistic nearf ield models for the receiving and transmitting antennas. The forward s cattering model is inverted analytically using the regularized pseudoi nverse operator to yield an algorithm for imaging the underground regi on based on scattered field measurements at a set of receiving antenna s. Whereas the usual inversion algorithms of DT require a lossless bac kground medium and ideal point sources and receivers, the algorithm de scribed here allows an attenuating background and arbitrary transmitti ng and receiving antennas. The algorithm places no restrictions on the radar frequency, and can thus include shallow imaging applications wh ere the wavelengths are on the same order as the depth of buried objec ts of interest. Versions of the algorithm are given for both the three dimensional and the 2.5-dimensional cases. Results are given of compu ter simulations designed to test the algorithm.