Handheld landmine avoidance system

The recent miniaturization of GPS receivers has made it possible to design a mobile "personal safety" system to help individuals avoid mapped landmines left over from previous conflicts. The handheld system continually compares the bearer\´s GPS-reported position with a compressed map of mined danger areas, sounding an alarm on approach. Two kinds of mobile devices are supported: a wearable wristwatch model for general alarm-only use, and a PDA model that also allows for recording and uploading of discovered mine locations. The mobile devices are integrated into a complete Internet-connected support system, with a central GIS landmine map repository and regional map distributors capable of updating mobile devices in their immediate locales. The data representations allow the mine maps to be stored in compressed form, and the algorithms for real-time proximity calculations are designed to minimize the computation, memory, and power requirements of the wearable mobile device, so as to reduce its cost, without sacrificing accuracy