ABSTRACT
Much of the geophysics equipment used today for agricultural applications has the capability to be integrated with Global Positioning System (GPS) receivers so that positional data can be obtained at the same time geophysical measurements are collected. Integration of GPS with resistivity and electro magnetic induction equipment already allows soil electrical conductivity to be mapped over large farm elds in just a few hours time. The GPS is a satellite-based, all-weather, continuous, global radionavigation and time transfer system, designed, nanced, deployed, and operated by the U.S. Department of Defense (DOD). The system was originally intended for military applications, but in the 1980s, the U.S. government made it available to civilian users, free of any subscription fees or setup charges. The rst GPS satellite was launched on February 22, 1978, and in 1993, the system was declared fully operational. During the following years, the breadth and the scope of the GPS applications exploded in the civilian market, taking advantage of the systems’ full and sustained operability. As a result, radionavigation-based positioning and tracking is currently everpresent in a number of science, engineering, mapping, and everyday life applications.
