Seismic and Acoustic Target Locating Devices (TLD-4 and TLD-5).

The rport describes a development program under Project REMBASS. Technical requirements were for field deployable sensor devices capable of detecting and reporting the presence of military vehicles within specified detection ranges. In addition, alarms were required indicating two relative range positions and time instant of closest approach to the sensor of the target vehicles. Two systems were developed, one sensing airborne acoustic emanations, the other earth borne seismic vibrations. The report provides a description of the signal analysis investigation leading to the final concepts and also gives details of the concept implementation and test results.