Laser Ultrasound Noncontact Seismic System

The U.S. Air Force urgently needs a rapid nondestructive evaluation (NDE) technology to determine the load-carrying capacity of runways for aircraft operations. To meet this need, Physical Optics Corporation (POC) proposes to develop a new Laser Ultrasound Noncontact Seismic (LUNS) system to conduct advanced pavement seismic analysis without mechanical contact between the system and the pavement being inspected. Seismic waves will be excited in the pavement by a pulsed Nd:YAG laser, and displacements of the pavement surface will be measured by a laser Doppler vibrometer. After data processing, the stiffness of the pavement, base, and subgrade will be evaluated. Wholly optical instrumentation makes the system significantly lighter than comparable state-of-the art systems, and enables it to measure continuously. The LUNS system will be mounted on a robotic platform for autonomous inspection of airfields. In Phase I we will build a laboratory prototype LUNS to demonstrate the feasibility of the concept, and in Phase II a fully packaged prototype will be developed and field tested to address both Air Force and commercial needs.