Pulsed Field System for Detecting the Presence of a Target in a Subsurface Environment.
Abstract
In a method and apparatus for searching a subsurface environment to detect the presence of a target therein, an electromagnetic field is emitted which comprises successive electromagnetic pulses of selected duty cycle, the time interval between pulses comprising a zero emission interval and a sampling interval, the sampling interval following the zero emission interval, and the polarity of the pulses of the emitted field alternating at a selected alternating frequency. The emitted field is projected into the environment from a selected location, and the electromagnetic field proximate to the selected location is sampled during each of the sampling intervals to provide a train of proximate field samples. The train of proximate field samples is spectrum analyzed to determine whether or not the field proximate to the selected location contains a component having a frequency which is equal to the alternating frequency. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 18, 1991
- Accession Number
- ADD015074
Entities
People
- Clarence F. Ramstedt
Organizations
- United States Department of the Navy