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Remote Sensing for Electric and Gravity Fields


OBJECTIVE: Demonstrate the technology to remotely measure electric and gravity/gravity gradiometry fields. DESCRIPTION: Electromagnetic and gravity intelligence, surveillance and reconnaissance (ISR) signatures are useful for revealing and characterizing adversaries"operations but these signatures decay rapidly with distance. Electric field signatures are from electrical power generators and power distribution systems. Gravity signatures are from the presence or absence of mass (in the case of an underground tunnel or facility). Current electric field and gravity field measurement methods require close-access sensor emplacement or low-flying airborne platforms. These are operationally unsuitable because of their difficult access requirements and low coverage rates. The goal of this effort is to replace those traditional point sensing technologies requiring sampling near a facility and providing limited spatial extent with remote sensing methods that decouple the sensor hardware from the measurement point and enable operationally attractive stand-offs and fast search rates. Such a system would operate from an aerial system, be able to scan from a distance of 10 kilometers, and have sufficient sensitivity to detect the operation of generator, the operational status of a power line (on/off), and the presence of an underground facility. DARPA is not interested in improved point sensors where the field measurement point and the sensor hardware are at the same location, tomographic based solutions whereby a remote field is calculated from an array of local point measurements, or clutter rejection techniques to improve local measurements of remote fields. Science and technologies may exist to achieve this goal. The commercial Electrical Single Particle Aerodynamic Relaxation Time (E-SPART) analyzer measures the secondary effect of a particle deflection in an AC electric field to determine the particle size and charge. The Stark effect perturbs emissions from atomic and molecular species in the presence of an electric field. Particles motion is influenced in the presence of a gravitational field. PHASE I: Propose a system that can achieve the measurement of an electric or gravity field at a distance of 10 kilometers. Demonstrate the sensitivity that the system could achieve through analysis. Experimentally demonstrate a key technology needed to achieve the realization of the system. PHASE II: Experimentally demonstrate the system at increasing distances and level of sensitivity. Ideally, achieve a standoff of 10 kilometers against the target sets identified above. Propose an operational configuration of the system to meet the requirements for an airborne system which is able to rapidly scan a large area. PHASE III: Potential benefit to the military/DoD; provides a capability to locate hidden underground facilities by detecting their electric and gravity signatures. Underground facilities are often concealed to prevent visual observation, but electric and gravity signatures are difficult to obscure. Remote detection of these signatures enables detection of facilities in denied access areas. Potential commercial benefit: Provides a capability to rapidly survey powerlines and power grids to determine breaks in power service. This is especially important after natural disasters when extensive power outages require expeditious location of broken powerlines to facilitate restoration of power service. REFERENCES: 1) AC Stark Effect,[2] Gravitational settling,
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