Program Summary
State-of-the-art military sensors rely on “active electronics” to detect vibration, light, sound or other signals for situational awareness and to inform tactical planning and action. That means the sensors constantly consume power, with much of that power spent processing what often turns out to be irrelevant data. This power consumption limits sensors’ useful lifetimes to a few weeks or months with even the best batteries and has slowed the development of new sensor technologies and capabilities. The chronic need to service or redeploy power-depleted sensors is not only costly and time-consuming but also increases warfighter exposure to danger.
The Near Zero Power RF and Sensor Operations (N-ZERO) program has the goal of developing the technological foundation for persistent, event-driven sensing capabilities in which the sensor can remain dormant, with near-zero power consumption, until awakened by an external trigger or stimulus. Examples of relevant stimuli are acoustic signatures of particular vehicle types or radio signatures of specific communications protocols. If successful, the program could extend the lifetime of remotely deployed communications and environmental sensors—also known as unattended ground sensors (UGS)—from weeks or months to years.
N-ZERO will initially focus on two broad areas. One centers on UGS capable of continuous monitoring for infrequent events, with near zero power consumption, but that activate a conventional sensor suite for further sensor data collection and processing when an event of interest is detected and confirmed. Only then would significant power be drawn. The other broad area concentrates on radio receivers that are continuously alert for friendly radio transmissions, but with near zero power consumption when transmissions are not present. A common feature of both focus areas is that the sensing is continuous—no events of interest or communications are missed—and that power-drawing confirmatory sensing and communications functions kick in only when triggered to do so.
To break the paradigm of using active power to sense infrequent, high-consequence events, the N-ZERO program calls for the exploitation of the energy in the signal signature itself to detect and discriminate the events of interest while rejecting noise and interference. This requires the development of passive or event-powered sensors and signal-processing circuitry. The successful development of these techniques and components could enable deployments of sensors that can remain “off” (that is, in a state that does not consume battery power), yet alert for detecting signatures of interest, resulting in greatly extended durations of operation.