With the combination of the Landsoner method and the Differential Electrical Sounding method, we can explore the rise and fall of bed rocks as well as single and multi-storey karst caves under the cover of a karst area, the proportion of depth to diameter being over 10-20:1. In addition, the depths of the top and the bottom can be accurately determined.
钟世航. 用陆地声纳法和微分电测深结合探查岩溶、洞穴[J]. 物探与化探, 2003, 27(3): 240-243.
ZHONG Shi-hang . THE COMBINATION OF LANDSONAR AND DIFFERENTIAL ELECTRICAL SOUNDING FOR THE EXPLORATION OF KARST AND UNDERGROUND CAVES. Geophysical and Geochemical Exploration, 2003, 27(3): 240-243.