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oa Finite-difference modeling of ground-penetrating radar data: The zero-offset approximation
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 3rd EEGS Meeting, Aug 1997, cp-95-00017
- ISBN: 978-94-6282-128-6
Abstract
Most ground-penetrating radar suveys are acquired in quasi zero-offset mode, Le. source-receiver offsets are small compared to the target depth. The correct way to realistically model such an experiment would be to compute a corresponding sequence of common-offset radargrarns. In finite-difference time domain (FDTD) modeling this approach would be excessively expensive and hence is substituted by initiating a downward travelling plane wave at the earth's surface. However, this method of zero-offset modeling is only realistic for horizontafly layered, one-dimensional media, and thus is unsatisfactory in most realistic situations and defeats the very purpose of finite-difference rnodeling. Therefore, we propose an alternative approach based on the "exploding reflector" concept. This approximation is more realistic, even in highly complex media, and is only marginaily more expensive than the plane wave method.