UWB Sensor Web Based Phased Array

Unattended ground sensors (UGSs) are becoming much more useful tools to the tactical commander, thanks to recent advances in technology. The emphasis on low cost is driving many military developers to adopt commercial communications technologies. For manyapplications - such as systems that could replace anti-personnel landmines, simple, inexpensive individual devices deployed in large numbers are likely to be the source of battlefield awareness in the future. Under the proposed work, we will developultra-low power UWB hardware-based system for low false-alarm rate detection of (human) intruders in a realistic environment over realistic ranges. We will perform both field experiments with actual hardware, as well as sophisticated hybridraytracing/finite element RF simulation codes. Our system will use the radio links between nodes themselves as means of intruder detection and tracking. In addition, we will develop the means whereby groups of radios within an ad hoc network cancooperatively transmit so as to achieve constructive interference at a desired receiver. This will yield very significant increases in range, and also decrease the probability of detection in other directions over conventional transmission, which wouldreach the desired receiver. In addition, we will identify hurdles to practical implementation and use by the Navy. 1) Coherent transmission of sensor nodes would lead to lower power requirements per sensor, and extended range, sensitivity, andfor a given battery size. The same ad-hoc phased array capability would lead to applications in Synthetic Aperture Radar applications.2) Sensor hardware will be cheap, allow for the development of disposable sensor webs. This will enable applications as part of area denial systems to replace mine fields, or expensive complicated acoustic/seismic/IR based sensors.3) Commercial applications are in homeland security, border security, monitoring of border treaties, customs inspection, and electronic fence applications.