Airborne Geophysical Methods

Abstract

Developments in airborne geophysics have occurred so rapidly in the past several years that it is a difficult task to follow and record them all. Geophysics covers a broad spectrum of scientific endeavors and workers in one specialized field are often unaware of important events in another. Unlike any other science, geophysics has become identified not with a particular technology or discipline but with its objective—the study of the earth—and for this reason it embraces many different disciplines and traverses many established lines of communication. This chapter attempts to describe generally and discuss critically some of the airborne geophysical methods that have seen successful application in recent years. In geophysics, “methods” are not nearly as important as “applications.” Too often a method is used holus-bolus without any very precise idea of what it is supposed to indicate. One way of subordinating methods is to discuss them as they appear under the headings of applications or objectives. The applications covered in this chapter are more numerous than the methods, to avoid complicated cross-referencing; the methods of airborne geophysics have been grouped under the following headings: (1) Aeromagnetic, (2) low-frequency electromagnetic, (3) radiometric, (4) gravity, and (5) other remote-sensing techniques.