Fortran IV program to compute apparent resistivity of a perfectly conducting sphere buried in a half-space

A FORTRAN IV program is presented that computes apparent resistivity of a perfectly conducting sphere buried in a half-space at any depth and for any electrode configuration. The program is based on solution of the problem by the method of images.     

A FORTRAN program to compute vertical magnetic field of a horizontal rectangular loop on n-layered earth for em depth sounding

A FORTRAN program is described to compute the vertical magnetic field anywhere inside or outside a rectangular loop which carries a sinusoidally varying current and is horizontally placed on the surface of a n-layered earth. The program utilizes the concept of reciprocity and the known solution for a horizontal magnetic dipole source placed over a n-layered half-space. The computing algorithm is executable on a minicomputer like PDP 11/40 and as such is useful to many geoscientists who do not have access to mainframe computer, for computing model data to fit and interpret field observations from electromagnetic depth sounding experiments.