Patent ID: 6839027
Filing Date: 2005-01-04
Classification: G01S

Abstract:
1. A computer-implemented process for measuring the location of people and objects carrying radio frequency (RF) transmitters (TXs) that transmit messages to a plurality of RE receivers (RXs) located in a space each of which is in communication with a computer of a computer network, wherein each RX forwards data received from the TXs to the network via its associated computer, along with a value indicating the signal strength of the received TX transmission, the process comprising using a centralized computer of the network to perform the following process actions: capturing data provided from the RXs which comprises the signal strength of each TX transmission measured by each RX associated with a TX carried by a person or object of interest within the space; generating a locating signal strength vector representing the signal strength measured by each RX in response to the same TX transmission associated with the TX carried by the person or object of interest; for each locating signal strength vector generated, comparing the locating vector to previously generated calibration signal strength vectors to determine what calibration vector is most likely to correspond to the locating vector based on any previous computed locations for the person or object being located and a prescribed set of allowable transitions between locations assigned to the calibration vectors, wherein each calibration signal strength vector represents what the signal strengths measured by each RX in response to a TX transmission would be if a TX is placed at said assigned locations in the space, and deeming the person or object being located to be at the location assigned to that calibration vector.