Low-power-low-cost undersea telemetry system

As scientists strive to gain better measurement resolution of undersea phenomena one primary method for success is to increase the sensor field gain. Often this option is discarded simply because of the power or cost constraints associated with upgrading an installed infrastructure. General Dynamics has addressed this subset of "limiters" by developing an enabling technology that provides, in many cases, an order of magnitude reduction in both cost and telemetry power while retaining the inherent reliability, thereby ensuring the best return on investment for large-scale research programs. This enabling technology is a new telemetry engine, designed to multiplex a substantial number of sensor outputs onto a four-wire local bus without the need for an "A/D, digital transmission and timing" subsystem at each sensor location. Instead, this novel approach deploys a simple device at each sensor location to modulate the line impedance to produce a varying, and accurately measurable impedance reflection that is proportional to a sensor (acoustic, nonacoustic etc.) output Sensor multiplexing is achieved through embedded pulsing of a synchronization and strobing signal that also serves as the power supply for the sensor telemetry. With the fundamental telemetry engine requiring a nominal 3 milliwatts per channel, the ability to deploy this local telemetry system to support sensor field expansions becomes much more feasible. Large systems are constructed by aggregating the recovered time-domain local sensor data into digital frames, achieved via low-power termination electronics that are compatible with any standard transmission format such as ethernet or synchronous optical network/asynchronous transfer mode (SONET/ATM).