Novel Technique Towards Hydrogeological Characterization of a Rockmass - A Millimeter-Wave SAR Approach

Unplanned roof failure in underground coal mines is often associated with weak strata conditions. The most common roof rock in coal mines are shale, mudstones or claystones. These sedimentary rocks are extremely moisture sensitive. Hence, water percolating through the strata can result in reduction of strength of these rocks. Traditional contact based geophysical inspection techniques involve physical installment of large sensor arrays to map the target rockmass. This paper proposes a millimeter wave synthetic aperture radar (SAR) based non-contact technique for mapping water saturation of a rockmass. A unique SAR phase processing algorithm has been proposed. Furthermore, actual experiments have been conducted with shale rock specimens to relate SAR phase with the change in water saturation.