Underground mining operations for raw materials are planned and monitored using geological measurements. One method is drill-core analysis; another is borehole radar, which maps the surrounding area of a borehole.
Project Details
Most borehole radar systems use omnidirectional receiving antennas. These systems can measure reflector distance, whereas directional antennas can also estimate the azimuthal angle. The antenna dimensions are limited by the borehole diameter. Therefore, the signal wavelength is much greater than the radial antenna dimension, resulting in small received signal levels.
Low antenna sensitivity is best handled with adaptive receiver electronics. For best results, the electronics must be located at the antenna feed point. The required communication link must not disturb the antenna properties through poorly arranged electrically conductive materials.
Receiver Design for a Directional Borehole Radar System
This work contains the system design of a directional receiver system with a focus on adaptive electronics at the antenna feed point. The receiver is designed for minimum noise, which results in parameter inaccuracies. In this context, a calibration method was developed to synchronize the receiver channels and correct the measurement data. The implemented receiver was analyzed with measurement data recorded in underground mines.