Shaeffer, John F. | Engineering Papers

NASA NTRS1995

Method-Of-Moments Code For Electromagnetic Scattering

MOM3D computer program implementing method-of-moments algorithm for analysis of electromagnetic waves on open or closed three-dimensional, perfectly conducting or resistive surfaces. Primary emphasis in analysis upon computation of radar cross section under plane-wave illumination. Also provides for excitation via local ports for computation of gain patterns and input impedances of antennas. Written in FORTRAN 77. Two machine versions available. One, UNIX version (LAR-15074). Other, IBM PC version (LAR-15130). UNIX version also available as part of package, COS-10048, includes EM-ANIMATE, IRIS program capable of displaying and animating MOM3D results.

Shaeffer, John F.↗

NASA NTRS1992

MOM3D method of moments code theory manual

MOM3D is a FORTRAN algorithm that solves Maxwell's equations as expressed via the electric field integral equation for the electromagnetic response of open or closed three dimensional surfaces modeled with triangle patches. Two joined triangles (couples) form the vector current unknowns for the surface. Boundary conditions are for perfectly conducting or resistive surfaces. The impedance matrix represents the fundamental electromagnetic interaction of the body with itself. A variety of electromagnetic analysis options are possible once the impedance matrix is computed including backscatter radar cross section (RCS), bistatic RCS, antenna pattern prediction for user specified body voltage excitation ports, RCS image projection showing RCS scattering center locations, surface currents excited on the body as induced by specified plane wave excitation, and near field computation for the electric field on or near the body.

Shaeffer, John F.↗