Computer program to calculate resistivities and layer thicknesses from Schlumberger soundings at the surface, at lake bottom and with two electrodes down in the subsurface

A computer program is presented that calculates thicknesses and resistivities of a layered earth from three different variations of Schlumberger arrangements:(1)The usual Schlumberger method with 4 electrodes at the surface.(2)Lake bottom arrangement: 4 electrodes at the bottom of waters like lakes, rivers or the sea.(3)Two potential electrodes at the same depth in the ground and two electrodes at the surface.