2009 Annual Report
1a.Objectives (from AD-416)
The objective of this cooperative research project is to develop an acoustical monitoring tool for detecting subterranean termites. Primary target pest is the Formosan subterranean termite (Coptotermes formosanus) in structures, trees, and soil.
1b.Approach (from AD-416)
Acoustical apparatuses will be constructed to detect unseen infestations of insects. Devices will be based on recognition of sound-producing acitivities. Recognition will be developed from databases sounds recorded under an array of substrates and environmental conditions.
Our main mission is to develop instruments and devices that can help in detecting termite infestations in a non-invasive way. One of the efficient ways to detect termite infestations is to use laser-based vibration measurement(Laser Doppler Vibrometery, LDV.) We have extensively investigated the use of LDV for termite detection and compared that technology to other existing and proposed technologies. Few modifications are being studied in order to increase the LDV sensitivity and dynamic range. To improve the quantification and analysis of the acquired LDV data, we have developed a Bayesian-based Model that enhances the analysis of vibration frequencies and amplitude measurements. We have investigated Micro Electro-Mechanical Systems (MEMS) technology, and tested MEMS microphones and accelerometers for termite detection. These chips offer an inexpensive solution to the detection process. In order to accommodate these chips, we had to make our own electronics that will produce a functioning device. Comparisons were made between MEMS devices and other accelerometers, along with the LDV vibrometer. The electronic circuits used with the phonograph cartridges were improved, with emphasis on reducing noise and on increasing the signal to noise ratio. We are investigating ways to implement these cartridges in a practical system that can be used easily by pest control personnel. To measure the force and vibration amplitudes of soldiers' headbanging, we initiated experiments in which soldiers are forced to head bang. These movements were recorded by a high speed camera that can take up to 8,000 frames per second. Using these recordings, and by measuring the weights of the termite heads and bodies, we obtained the average force that a soldier produces by banging its head. Termite tremulation (body shaking) is another alarm response for termites that can be detected acoustically. We have investigated tremulation in field and laboratory colonies, using a high-speed camera. A termite tremulating, oscillates back and forth, by first lunging forward and then backward. The forward and backward motion can be repeated up to 14 times. It appears from these observations, that these vibrations may be transmitted up to 5.5 cm, but usually tremulating individuals are much closer. Progress in this project is monitored through Annual FST Technical Committee Meetings, reports, regular meetings with cooperators, routine phone calls, and e-mail correspondence.