IMPROVED NON-GPS POSITIONING SYSTEMS

摘要

A method for determining the relative position of each of a plurality of devices, each device having a three-dimensional local coordinate system; the method comprising the steps of: aligning one of the axes of the local coordinate system of each device with a reference direction; and determining the elevation and azimuth angles, and distance, from each device to another such device. Preferably the reference direction is collinear with the direction of gravity. Preferably the method further comprises a step of aligning the local coordinate systems of the devices, particularly preferably by propagating the local coordinate system of a first device to a second device, and so on throughout all the devices. Preferably each device also comprises a wireless sensor, and may thus collect and generate sensing data such as temperature data, pressure data, force data, stress data, strain data, humidity data, vibration data, presence data, pH data, radioactivity data, gas or liquid level data, or gas or liquid flow rate data. As a consequence of the devices' positioning capability, the method may further comprise each device transmitting location data together with the sensing data. The method may be implemented in areas where GPS positioning methods are not applicable or available, such as within underground tunnels, along pipes, inside buildings, or in war zones. Also provided is a system operable to determine the relative position of each of a plurality of devices, and a device for use in such a system.