On Calculating Transient Electromagnetic Fields of a Small Current-Carrying Loop Over a Homogeneous Earth,

摘要

The basic theory of airborne EM surveying,in the time domain,is considered. Rather than resorting to tedious double numerical integration, a more direct approach is adopted. This method,valid in the quasi-static regime,is illustrated for a homogeneous flat earth. The results exhibit a number of clear-cut features that are relevant to remote sensing. For example, a vertical co-axial loop system has a desirable transient response from the standpoint of yielding conductivity data without requiring accurate information on the height of the device above the ground. (Author)