Advanced Signal Processing for Detailed Site Characterization and Target Discrimination
Abstract
This document details successful validation of our physics-based mean field and early time approaches to modeling of time-domain electromagnetic (TDEM) responses of compact, highly conducting targets. Specifically, we apply our methods to the analysis of laboratorystyle data collected by the NRL TEMTADS system using artificial spheroidal targets. The models use the detailed system parameters (transmitter and receiver coil position, orientation, and geometry; transmitted pulse waveform; target position, orientation, geometry; target conductivity and permeability) to generate first principles predictions for the measured time-domain voltages. The models are designed to be essentially exact for spheroidal targets, and, as described in the remainder of this document, the remarkable agreement between measurements and predictions strongly supports this conclusion. The outline of the remainder of this document is as follows. Details of the EM theory underlying the models, and their numerical implementation, will be detailed elsewhere, but a basic overview is given in Sec. II. In Sec. III the basic parameters of the NRL TEMTADS system are detailed. In Sec. IV model predictions are compared with TEMTADS data for spherical targets, for which an exact analytic theory also exists (Sec. IV A); prolate (elongated) and oblate (discus-like) spheroidal targets (Sec. IV B). Finally, conclusions and directions for future work are presented in Sec. V.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2001
- Accession Number
- ADA593499
Entities
People
- Peter B. Weichman