A Whole Closed Space Intrinsically Safe GPR System for Detection of Geological Hazard Sources in Coal Mines

Detailed detection of geological hazard sources is an important and yet challenging problem that remains unsolved. In this letter, we propose a whole closed space intrinsically safe Ground Penetrating Radar (GPR) system for geological hazard detection in coal mine roadway. Compared with many existing GPRs for half-space, this GPR system is characterized by achieving a stable radiation pattern and improved gain throughout the bandwidth. The improved performance for the system is achieved by the newly microwave front end design, adding round corners on the antenna radiation surface to improve radiation efficiency, designing resistive loading for better impedance matching, and optimizing shielding cavity dimensions to eliminate environmental interference. For design validation, a field experiment in mine roadway conditions is conducted, and the results show that the developed system has a good performance in mining roadway with depth detection accuracy at 0.5 m and direction detection accuracy at 1.5 m.