This thesis presents a theoretical analysis and applied evaluation of the steppedfrequency radar technique and shows that significant performance benefits can be achieved in ground penetrating radar (GPR) applications. These benefits are suc cessfully demonstrated in field trials of a newly designed stepped-frequency GPR system.An original contribution has been made in establishing a unified characterisation of the performance of GPR for constant Q materials. This enables the maximum penetration depth of a GPR system to be characterised as a fixed number of wave lengths which is constant for any frequency. Similarly, the resolution is expressed as a fixed number of wavelengths which is also constant with frequency. These expressions prove to be a useful design tool in characterising GPR performance in dependently of frequency, and in selecting the waveform parameters for a defined application.A rigorous theoretical study of the stepped-frequency radar technique is un dertaken, which demonstrates the "synthesis" of an impulse waveform using an IDFT-based matched filter with minimum-phase. It is concluded that a physically realisable stepped-frequency radar has far-reaching benefits in the form of higher processed mean energy than an impulse radar with the same frequency bandwidth.A 1-2 GHz stepped-frequency GPR prototype has been completely designed and built to test the above theories. The primary application for this system design is the high-resolution mapping of thin coal seam structures in open-cut coal mines.The 1-2 GHz frequency band is selected to meet the performance requirements of one metre penetration and five centimetre resolution in coal.A novel technique is presented which corrects the broadband quadrature receiver errors in the stepped-frequency radar prototype. It is shown that the technique suppresses the Hermit,Ian images by more than 50 dB below the target responses.The external loop gain of the system is measured to be 156 =b 6 dB for bow-tie antennas and 166 dz 6 dB for horn antennas. These figures represent the maximum power loss that the radiated signal, integrated over a defined ten millisecond interval, can tolerate between the transmit and receive antennas, for a defined signal-to-noise ratio of 10 dB. The performances of typical impulse GPR systems are noted in the literature to lie between 100-130 dB under similar conditions.The system is successfully field tested at various sites, including two open-cut coal mines. The resulting images from these sites demonstrate a penetration depth of at least 80 centimetres and a resolving power of better than 8 centimetres.

No abstract

No abstract

No abstract

Determining slope stability in a mining operation is an important task. This is especially true when the mine workings are close to a potentially unstable slope. A common technique to determine slope stability is to monitor the small precursory movements, which occur prior to collapse. The "slope stability radar" has been developed to remotely scan a rock slope to continuously monitor the spatial deformation of the face. Using differential radar interferometry, the system can detect deformation movements of a rough wall with sub-millimeter accuracy, and with high spatial and temporal resolution. The effects of atmospheric variations and spurious signals can be reduced via signal processing means. The advantage of radar over other monitoring techniques is that it provides full area coverage without the need for mounted reflectors or equipment on the wall. In addition, the radar waves adequately penetrate through rain, dust and smoke to give reliable measurements, twenty-four hours a day. The system has been trialed at three open-cut coal mines in Australia, which demonstrated the potential for real-time monitoring of slope stability during active mining operations.