# US 2019/0187243 A1 · Aircraft acoustic position and orientation detection method and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0187243 A1 - Document ID: US20190187243A1 - Status: Published application - Kind: A1 - Application number: 16/282,937 - Filed: 2019-02-22 - Published: 2019-06-20 - Earliest claimed: 2016-08-25 - Assignees: Intelligent Sciences, Ltd. - Applicants: Intelligent Sciences Ltd. - Inventors: Jacques Y. Guigné; Nicholas G. Pace - Web page: https://patentgrep.com/patent/US20190187243A1 ## CPC - G01S 5/22: Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements (G01S5/28 takes precedence) - G01C 5/005: {altimeters for aircraft (G01C5/02, G01C5/06 take precedence)} - G01S 5/186: {Determination of attitude (using inertial means G01C9/00; control of attitude G05D1/49)} - G01S 5/24: Position of single direction-finder fixed by determining direction of a plurality of spaced sources of known location - G01S 5/26: Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements (G01S5/28 takes precedence) - G01S 5/30: Determining absolute distances from a plurality of spaced points of known location - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) ## 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. ## Claims ### Claim 1 A method for determining position of an aircraft with reference to a location on the ground, comprising: transmitting an acoustic signal from a position on the aircraft to an array of spaced apart acoustic sensors proximate the location; 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; and determining the position of the aircraft from the time difference of arrival or the arrival time. ### Claim 2 (depends on 1) The method of claim 1 wherein the time of arrival is determined using a substantially zero latency synchronization signal communicated between the aircraft and the location on the ground. ### Claim 3 (depends on 1) The method of claim 1 wherein the position is determined by scanning a plurality of assumed aircraft positions, calculating an expected arrival time or an expected time difference of arrival for each of the assumed positions with reference to a position of each of the spaced apart acoustic sensors and determining the position of the aircraft when a summed detected signal at the aircraft reaches a maximum value. ### Claim 4 (depends on 1) The method of claim 1 further comprising: transmitting an acoustic signal from a plurality of spaced apart positions on the aircraft, each of the transmitted signals being coded to enable separate identification of each transmitted signal in a composite signal detected by each acoustic sensor; determining either a time difference of arrival or an arrival time of each of the plurality of transmitted signals; and determining the position of the aircraft and pitch, roll and yaw of the aircraft using the time difference of arrival or the time of arrival of each of the plurality of transmitted signals. ### Claim 5 (depends on 4) The method of claim 4 wherein an arrival time of each acoustic signal is determined by cross correlation of the signal detected by each sensor with a replica of each of the transmitted signals and determining a time of a peak of a value of the cross-correlation. ### Claim 6 (depends on 4) The method of claim 4 wherein each of the coded signals has substantially zero cross correlation with any of the other coded signals. ### Claim 7 (depends on 4) The method of claim 4 wherein the coded signals comprise at least one of Gold code, Kasami code and maximum length code. ### Claim 8 (depends on 4) The method of claim 4 wherein a length of the coded signals is selected to enable a radiated power of each coded signal to be less than an ambient noise level at the aircraft. ### Claim 9 A method for determining position of an aircraft with respect to a position on the ground, comprising: transmitting a signal from each of at least three spaced apart positions proximate the position to the aircraft; detecting each of the transmitted signals at a sensor on the aircraft, the sensor configured to determine angle of direction of each coded signal from its respective position of transmission; and determining the position of the aircraft from the determined angles. ### Claim 10 (depends on 9) The method of claim 9 wherein each of the transmitted signals comprises a single frequency, each of the transmitted signals comprising a different frequency. ### Claim 11 An apparatus for determining a position of an aircraft with respect to a location on the ground comprising: at least one acoustic transmitter on the aircraft; an array of acoustic sensors arranged in a selected pattern proximate the location on the ground; means for determining at least one of (i) a time difference of arrival of the acoustic signal between each of the acoustic sensors and a reference acoustic sensor and (ii) an arrival time of the acoustic signal at each of the spaced apart acoustic sensors; and means for determining the position using the determined time differences of arrival or the arrival time. ### Claim 12 (depends on 11) The apparatus of claim 11 further comprising a substantially zero latency synchronization signal transmitter disposed on the aircraft in signal communication with the means for determining arrival time of the acoustic signal. ### Claim 13 (depends on 11) The apparatus of claim 11 further comprising a plurality of spaced apart acoustic transmitters disposed on the aircraft, each of the acoustic transmitters coupled to a driver to transmit a signal being coded to enable separate identification of each transmitted signal in a composite signal detected by each acoustic sensor; determining either a time difference of arrival or an arrival time of each of the plurality of transmitted signals; and determining the position of the aircraft and pitch, roll and yaw of the aircraft using the time difference of arrival or the time of arrival of each of the plurality of transmitted signals. ### Claim 14 (depends on 13) The apparatus of claim 13 wherein an arrival time of each acoustic signal is determined by cross correlation of the signal detected by each sensor with a replica of each of the transmitted signals and determining a time of a peak of a value of the cross-correlation. ### Claim 15 (depends on 13) The apparatus of claim 13 wherein each of the coded signals has substantially zero cross correlation with any of the other coded signals. ### Claim 16 (depends on 13) The apparatus of claim 13 wherein the coded signals comprise at least one of Gold code, Kasami code and maximum length code. ### Claim 17 (depends on 13) The apparatus of claim 13 wherein a length of the coded signals is selected to enable a radiated power of each coded signal to be less than an ambient noise level at the aircraft. ### Claim 18 An apparatus for determining position of an aircraft with respect to a position on the ground, comprising: at least three spaced apart acoustic transmitters proximate the position to the aircraft, each acoustic transmitter driven by a single frequency signal different in frequency than the signal used to drive other of the plurality of transmitters; a directionally sensitive acoustic sensor on the aircraft, the sensor configured to determine angle of direction of each coded signal from its respective position of transmission; and means for determining the position of the aircraft from the determined angles. ### Claim 19 (depends on 18) The apparatus of claim 18 wherein each of the transmitted signals comprises a single frequency, each of the transmitted signals comprising a different frequency. ### Claim 20 An apparatus for determining position of an aircraft with respect to a position on the ground, comprising: an acoustic receiver on the aircraft; an array of spaced apart acoustic transmitters proximate the position on the ground; means for summing the signals detected by the acoustic receiver from each of the spaced apart transmitters; means for time domain beamforming the signals from the spaced apart transmitters; and means for determining the location of the aircraft when an assumed position in a scan of possible positions results in the time domain beamformed signals most closely matches the summed detected signal.