Development and application of air-coupled GPR antenna for coal-rock interface detection in mines

Rapid and high precision detection of coal-rock interface is one of the key problems in intelligent coal mining. In this paper, an air-coupled ground penetrating radar (GPR) antenna is developed for coal-rock interface detection in fully mechanized mining face, which can realize non-contacting, high precision, high-resolution detection during the mining process. The main features of the air-coupled GPR antenna are ultra-wideband, narrow beam, and high gain. For the vertical polarization pattern at 1200 MHz, the main lobe amplitude is 6.29dBi and the main lobe width (3 dB) is 108.3 degrees, as well as the relative bandwidth of the antenna can reach 51%. For design validations, the novel air-coupled GPR antenna developed in this paper is tested in mine, the detection error and the average error percentage are +/- 1.2 cm and 8.6%, respectively, which shows the superior detection ability of the novel air-coupled GPR antenna and the applicability in complex geological environment, providing technical support for the identification of coal-rock interface in intelligent coal mining.