A theoretical approach to cross-hole radar measurements is presented. An approximate analytical form for the current distribution on an antenna in a borehole is derived, and the theoretical receiving signal of the borehole radar in the cross-hole measurement is calculated. Theory is compared in the time-domain with the measured borehole radar signal obtained in a salt deposit. The radiation pattern of a borehole radar excited by a pulse is discussed. The accuracy of tomographic analysis, which is often applied to cross-hole radar measurements, is strongly governed by this radiation pattern. It is found that, in practice, most borehole radars have a pattern of a λ/2 dipole antenna. However, the radiation pattern can be deformed by short pulse excitation, loading by the surrounding media, and coupling to the logging cable.
|Number of pages||6|
|Journal||IEEE Transactions on Geoscience and Remote Sensing|
|Publication status||Published - 1991 Nov 1|
ASJC Scopus subject areas
- Computers in Earth Sciences
- Geochemistry and Petrology
- Electrical and Electronic Engineering