GeoTDR, Inc. is a subsidary of Geotechnical Consultants, Inc. which designs, installs, and monitors remote automated instrumentation systems throughout the United States. The particular strength is providing clients with capabilites to managem risk with remote, automated monitoring and email notification of alarm situations. Applications include monitoring subsidence over aboandoned and active mines, monitoring sinkhole development in karst areas, monitoring movement of slopes and embankments, monitoring changis in groundwater conditions GeoTDR personnel have been implementing TDR technology for diverse applications since 1981. Kevin O'Connor. P.E., Ph.D. is co-author with Charles H. Dowding P.E., Ph.D. of "GeoMeasurments by Pulsing TDR Cables and Probes," published in 1999.