Fiber Optic Vector Sensor Arrays

Twinline and vector sensor towed arrays correct the left-right ambiguity inherent in hydrophone systems and offer significant performance and tactical advantages against noisy interferers in a non-isotropic noise environment. A vector sensor array is preferred because it provides similar capability to twinline and uses a single line array versus towing two independent arrays. This difference dramatically reduces submarine deployment, retrieval, stowage and handling requirements. Vector sensor arrays are comprised of a series of sensor “suites” that consist of three orthogonal accelerometers and a hydrophone. Multiple spatially separated, fiber optic accelerometer and hydrophone sensors are used in each suite to improve flow induced noise performance. Using Chesapeake Sciences’ TB-33 fiber optic hydrophone and towed array architecture coupled with the Navy’s model for a fiber optic accelerometer provides an ideal opportunity to leverage the designs into a single vector sensor array. TB-33 automated manufacturing and minimal outboard electronics improves reliability and decreases manufacturing costs. Our Phase 1 effort focuses on designing a Thinline Optical Directional Array (TODA), developing a performance specification and prototype sensor. Phase II plans include assembly of a prototype array for extended Shallow Water Advanced Prototype (SWAP) in-water testing and analyses.