27 April 2000 Simple method for modeling radar reflections in a homogeneous halfspace, with applications
Author Affiliations +
Proceedings Volume 4084, Eighth International Conference on Ground Penetrating Radar; (2000) https://doi.org/10.1117/12.383524
Event: 8th International Conference on Ground Penetrating Radar, 2000, Gold Coast, Australia
We have developed a method to rapidly compute synthetic radar records from complex reflecting surfaces. The approach is a 3- D time domain Hemholtz-Kirchhoff (HK) representation, similar to Hilterman (1981), that includes the radiation characteristics of GPR dipoles on the surface of a uniform dielectric halfspace. Validity is established by making comparisons with published model results and by comparisons with field data. Comparison to the ray theory results of Zeng et al. (1997) show excellent agreement in reflection arrival times for pipes of various diameters. We also reproduce the non-specular reflection results of Schleicher et al. (1991), which show that large amplitude reflections can originate from the inflection points of curved surfaces. Our comparisons with field data use reflection records taken at a test site in Borden, Ontario, over horizontally oriented buried metal drums. The H-plane reflection data were collected using shielded 700-MHz dipoles. Our raw synthetic amplitude trends show reasonable agreement to the field data, but are not perfect. Using a small diameter synthetic dipole array, we show that the mismatch is most likely caused by antenna shielding effects. The versatility of the HK method is demonstrated by giving results for a number of interesting applications. These include synthetic records for crisscrossing pipes buried at various depths, reflection synthetics from a truncated cone representing the slag heaps in Daniels and Brower (1998), and reflections from a rough surface. The slag heap models demonstrate the effect of antenna polarization on reflections from sloping surfaces. Analysis of synthetic reflections from rough surfaces shows that the coda following the first impulsive arrival can be used to estimate the surface roughness. This is of interest for interpreting reflections from glacier data. Our results demonstrate that the HK method is useful in interpreting data, as well as for developing field survey strategies.
© (2000) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Roy J. Greenfield, Mark L. Moran, J. L. Davis, "Simple method for modeling radar reflections in a homogeneous halfspace, with applications", Proc. SPIE 4084, Eighth International Conference on Ground Penetrating Radar, (27 April 2000); doi: 10.1117/12.383524; https://doi.org/10.1117/12.383524

Back to Top