Patent ID: 7423580

Claim:
An RF system for finding a target T in three dimensional space, comprising: a slave unit disposed on the target T, said slave unit configured as a transponder; a monitoring unit configured as a transceiver for monitoring the location of the target T; a wireless communication system, said wireless communication system operating on a Radio Frequency (RF) bandwidth configured to allow communication between said slave and monitoring units, said monitoring unit configured to transmit a ranging signal to said slave unit, said slave unit responding to said ranging signal by transmitting a reply ranging signal, said wireless communication system further comprising: a processor for determining position information of the target T, said processor in communication with an antenna, said processor being configured to repeatedly determine values for said position information from: means for determining a transmission interval between said monitoring unit and said slave unit, said transmission interval being an elapsed time between transmitting said ranging signal and receiving said reply ranging signal, means for determining a calibration interval between each of said monitoring unit and slave unit said calibration interval being a time interval of a period to normalize the circuitry of said monitoring and slave units, and means for determining an antenna propagation interval of said units, said antenna propagation interval being an elapsed time of a signal measured as it passes through said antenna of said monitoring and slave units, and means for generating a measured distance between units in three dimensional space, said distance generating means determining said measured distance of the target T by a spherical virtual triangulation relationship when successive values of said position information has a predetermined logical relationship relative to said previous values between said monitoring unit and slave unit.