In the past few years, the Subsurface Sensing Laboratory (SSL) has devoted its efforts in the research of imaging the subsurface using electromagnetic (EM) methods. The applications of the research range from environment monitoring and detection to highway pavement inspections. We have successfully developed theory and software to simulate various subsidence EM sensors, including pulsed ground penetrating radar, single-frequency borehole-toorehole EM tomography systems, time-domain borehole tomography systems, pulsed borehole radar, and FM-CW radar.

To construct the image of the subsurface, we have developed a space marching inversion algorithm to establish two-dimensional conductivity images using data from a borehole radar. A special iterative inversion technique is established to image the subsurface using date from EM borehole tomography measurements. In the meantime, a measurement system has been developed to measure the the electrical property of materials such as cement and soils.

The SSL has also conducted other projects related to the telecommunications, spread spectrum systems and global positioning systems used in the date telemetry systems.

Research Area
• Development of Subsurface Sensing Equipment and Devices
• Study of Electromagnetic Light and other sensors
• Study of wireless and wired Telemetry system

Current External Sponsors
• National Science Foundation
• National Center for Earthquake Engineering
• Texas Department of Transportation
• Texas Higher Education Coordinate Board
• City of Houston
• Private Industry

Successful story
• Federal Funding: $340,000
• State Funding: $530,500
• Industry and Local funding: $60,000
• Graduated Ph.D's: 3
• Ph.D. in Progress: 5
• Graduated MS: 12
• MS Progress: 10
• Post Doctors: 3
• Visiting Scholars: 3

Imaging the Subsurface
• Electromagnetic imaging
• Cross-hole measurement (25 m separation)
• Inject liquid to the injection well
• Measure before and after injection
• Measurement was done by Lawrence-Livemore National Lab
• Imaging is performed at UH