Numerical modeling of subsurface communication, revision 1
Abstract
Techniques are described for numerical modeling of throughtheEarth communication. The basic problem considered is evaluation of the field at a surface or airborne station due to an antenna buried in the earth. Equations are given for the field of a point source in a homogeneous or stratified Earth. These expressions involve infinite integrals over wave number, sometimes known as Sommerfeld integrals. Numerical techniques used for evaluating these integrals are outlined. The problem of determining the current on a real antenna in the Earth, including the effect of insulation, is considered. Results are included for the fields of a point source in homogeneous and stratified earths and the field of a finite insulated dipole. The results are for electromagnetic propagation in the ELFVLF range, but the codes also can address propagation problems at higher frequencies.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 August 1985
 Bibcode:
 1985STIN...8614491B
 Keywords:

 Antenna Radiation Patterns;
 Antennas;
 Communication;
 Current Distribution;
 Electromagnetic Wave Transmission;
 Mathematical Models;
 Wave Propagation;
 Earth (Planet);
 Integral Equations;
 Point Sources;
 Stratification;
 Communications and Radar