Patent ID: 7616526
Filing Date: 2009-11-10
Classification: G01S

Abstract:
1. In an object location system comprising multiple sensor devices at different sites, a sensor device comprising: a sensor for sensing a detection signal from an object; means for transmitting data signals to other sensor devices of the object location system; means for receiving data signals from other devices of the object location system; and means responsive to one of the data signals, which include control data, received by the receiving means to switch the sensor device between: (a) a master mode, in which the sensor device is operable to transmit data derived from said sensed detection signal using the transmitting means; and (b) a slave mode, in which the device is operable to process the sensed detection signal in accordance with the data received, via the receiving means, from one of the multiple sensor devices in the master mode in order to determine a time delay between arrival of the detection signal at the sensor device and arrival of the detection signal at the one of said multiple sensor devices in the master mode, and to transmit data representative of the determined time delay using the transmitting means.