Seismic Instrusion Detectors

March 8th, 2005  

Topic: Seismic Instrusion Detectors


I am a TV producer based in California that works with the Japanese networks. One of my clients produces a program that airs on Fuji TV called "Fountain of Trivia." The show aims to bring interesting facts and the answers to questions from around the world to the Japanese audience.

We are doing a story on an unusual kind of Seismic Intrusion Detectors (SIDs) used during the Vietnam War. We have been lucky enough to find 2 of these devices (from somebody in another forum) which we have sent to Japan for the show, but we have not been able to locate paperwork or somebody with knowledge of how these SIDs functioned. Please let me know if you have, or know someone who has, worked with SIDs in the past who might be able to assist us. Below is a description of the device.

**These were small devices, mostly seismic. They consisted of a seismic detector, a transmitter, and internal antenna, and a battery in a fiberglass or plastic case made to look like a broken branch, a big leaf, or other piece of forest litter. One type of sensor was designed to look like animal droppings and was nicknamed “Turdsid” by the troops. They were usually delivered by air, dumped along a trail, road, or in a suspected base camp area. Because they were small, their batteries were small and transmitters were small. Battery life was not long -- a few days.

Thank you very much for your time and help.