ELECTROMAGNETIC MODELING OF THREE-DIMENSIONAL BODIES IN LAYERED EARTHS USING INTEGRAL EQUATIONS

An algorithm based on the method of integral equations to simulate the electromagnetic responses of three-dimensional bodies in layered earths has been developed. The inhomogeneities are replaced by an equivalent current distribution which is approximated by pulse basis functions. A matrix equation is constructed using the electric tensor Green's function appropriate to a layered earth, and it is solved for the vector current in each cell. Subsequently, scattered fields are found by integrating electric and magnetic tensor Green's functions over the scattering currents. Efficient evaluation of the tensor Green's functions is a major consideration in reducing computation time. We find that tabulation and interpolation of the six electric and five magnetic Hankel transforms defining the secondary Green's functions is perferable to any direct Hankel transform calculation using linear filters. A comparison of responses over elongate three-dimensional (3-D) bodies with responses over two-dimensional (2-D) bodies of identical cross-section using plane wave incident fields is the only check available on our solution. Agreement is excellent; however, the length that a 3-D body must have before departures between 2-D transverse electric and corresponding 3-D signatures are insignificant depends strongly on the layering. The 2-D transverse magnetic and corresponding 3-D calculations agree closely regardless of the layered host. (Author)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00963941
• Corporate Authors:

  American Geophysical Union

  2000 Florida Avenue, NW
  Washington, DC  United States  20009-1277
• Authors:
  • Wannamaker, P E
  • Hohmann, G W
  • SanFilipo, W A
• Publication Date: 1983-12-13

Media Info

• Pagination: p. 984
• Serial:
  • EOS Transactions
  • Volume: 64
  • Issue Number: 50
  • Publisher: American Geophysical Union
  • ISSN: 0096-3941

Subject/Index Terms

• TRT Terms: Algebra; Algorithms; Electromagnetic waves; Layered soils; Mathematical matrices; Mathematical models
• Old TRIS Terms: Body; Matrix algebra
• Subject Areas: Geotechnology; Highways; I41: General Soil Surveys;

Filing Info

• Accession Number: 00381243
• Record Type: Publication
• Files: TRIS
• Created Date: Mar 30 1984 12:00AM