Abstract:
A system for locating a mobile electronic device includes a plurality of acoustic transmitters arranged in a selected pattern within a volume. A first processor is in signal communication with each of the acoustic transmitters. The processor is programmed to drive each of the transmitters with a different coded signal. The signals are substantially decorrelated with each other. An electromagnetic signal transceiver is in signal communication with the processor. The processor is programmed to communicate a time reference signal to the mobile electronic device. The mobile device includes an acoustic receiver for detecting signals from the transmitters and an electromagnetic transceiver for receiving the time reference signal. The mobile device includes a second processor programmed for cross-correlating signals detected by the acoustic receiver with a replica of each of the different coded signals. The second processor has instructions programmed therein for calculating an acoustic travel time of acoustic signals between each transmitter and the acoustic receiver from the cross-correlated signals. At least one of the first processor and the second processor is programmed to determine the position of the mobile electronic device from the travel times.
Abstract:
A method for determining position of an aircraft with reference to a location on the ground includes transmitting an acoustic signal from a position on the aircraft to an array of spaced apart acoustic sensors proximate the location. The method includes at least one of (i) determining a time difference of arrival of the acoustic signal between each of the acoustic sensors and a reference acoustic sensor and (ii) determining an arrival time of the acoustic signal at each of the spaced apart acoustic sensors. The position of the aircraft is determined from the time differences of arrival and/or the arrival times.