Underwater Vertical Electric Field Detection

Acoustic sensing based sonobuoys are used in surveillance for detection and classification of marine vessels. However, there are situations, particularly in littoral environments, where the efficacy of acoustic sensors can be significantly compromised. In these instances, supplementary sensing techniques can provide performance enhancement. Passive electric field (E-field) sensors have the potential to provide useful information for tactical surveillance and classification of marine vessels, but current marine E-field sensors collect only horizontal E-field measurements. A sonobuoy capable of collecting vertical E-field in addition to horizontal components would enable exploitation of all E-field signals emanating from a submerged vessel. QUASAR Federal Systems proposes to develop an innovative underwater E-field sensor appropriate for collecting vertical E-field measurements over a large effective aperture that can be integrated with sensors that measure the horizontal E-field components. The vertical E-field sensor will be a low-cost design suitable for scale-up to mass production. The E-field sensors developed in the present program will be integrated into a standard sonobuoy in Phase II in collaboration with Ultra Electronics Undersea Sensor Systems Inc. (Ultra-USSI). We will also partner with Applied Signal Technology in the present effort to develop algorithms to model the proposed sensor and predict the resulting performance.