Analysis on Ability of Spaceborne Synthetic Aperture Radar Detecting Cavern in Bare Hillslope

Spaceborne Synthetic Aperture Radar has certain capacity of detecting underground things. According to the facet theory and radar image simulation method, the mountain slope with the underground cavern has been divided into many grids based on the radar resolution criterion. The radar echo intensity calculation formula has been got by considering the electromagnetic propagation in the rock mass and on the cavern roof. According to the calculation formula, the radar echo intensity calculating program has been done by the matlab sofrware, then the maximum detecting depth of the SAR has been studied with the criterion of minimum detectable signal power. Numerical examples show that the minimum rock thickness of the underground cavern to satisfy the anti-detecting demand is 2100mm by taking into account the current SAR detectability and rock electric property constant can influence the maximum detecting depth of the SAR very much by depth increasing together with the electric property constant raises. Key words—Synthetic Aperture Radar, underground cavern, radar echo intensity, minimum detectable signal power