# US 11,442,140 B1 · Determining a location of a vehicle using received surveillance signals > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,140 B1 - Document ID: US11442140B1 - Status: Granted - Kind: B1 - Application number: 16/902,699 - Filed: 2020-06-16 - Published: 2022-08-25 - Granted: 2022-09-13 - Earliest claimed: 2020-06-16 - Assignees: Honeywell International Inc. - Applicants: Honeywell International Inc. - Inventors: Arjun Bindu Jyothikumar; Thandava Krishna Edara; Hai Pham - Web page: https://patentgrep.com/patent/US11442140B1 ## CPC - G01S 5/02: using radio waves (using satellite radio beacon systems for determining position G01S19/00) - G01S 5/14: Determining absolute distances from a plurality of spaced points of known location - G01S 5/0072: {Transmission between mobile stations, e.g. anti-collision systems} - G01S 5/08: Position of single direction-finder fixed by determining direction of a plurality of spaced sources of known location - G01S 19/21: Interference related issues {; Issues related to cross-correlation, spoofing or other methods of denial of service} - G01S 19/49: whereby the further system is an inertial position system, e.g. loosely-coupled - G01S 19/51: Relative positioning - G08G 5/25: Transmission of traffic-related information between aircraft - 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 - G08G: TRAFFIC CONTROL SYSTEMS (guiding railway traffic, ensuring the safety of railway traffic B61L; arrangement of road signs or traffic signals E01F9/00; radar or analogous systems, sonar systems, lidar systems specially adapted for traffic control G01S13/91, G01S15/88, G01S17/88; {radar or analogous systems, sonar systems, lidar systems specially adapted for anti-collision purposes G01S13/93, G01S15/93, G01S17/93}) ## Abstract In some examples, a system includes at least three receivers configured to receive a surveillance packet from another vehicle at respective arrival times. The system includes a first receiver configured to receive a surveillance packet from the other vehicle at a first time. The system also includes a second receiver configured to receive the surveillance packet from the other vehicle at a second time. The system further include a third receiver configured to receive the surveillance packet from the other vehicle at a third time. In addition, the system includes processing circuitry configured to determine a location of the ownship vehicle based on the received surveillance packet and the respective arrival times. ## Claims ### Claim 1 A system configured to mount on an ownship vehicle, the system comprising: at least three receivers configured to receive a surveillance packet from another vehicle at respective arrival times, the at least three receivers comprising: a first receiver configured to receive, at a first time, a surveillance packet from the other vehicle; a second receiver configured to receive, at a second time, the surveillance packet from the other vehicle; and a third receiver configured to receive, at a third time, the surveillance packet from the other vehicle; and processing circuitry configured to determine a location of the ownship vehicle based on the received surveillance packet and the respective arrival times. ### Claim 2 (depends on 1) The system of claim 1, wherein the processing circuitry is configured to determine the location of the ownship vehicle based on: a location of the other vehicle indicated by data in the received surveillance packet; and a time difference of arrival for the respective arrival times. ### Claim 3 (depends on 1) The system of claim 1, wherein the processing circuitry is configured to determine the location of the ownship vehicle using a multilateration based on: the respective arrival times; relative positions of the at least three receivers; and data from an inertial navigation system. ### Claim 4 (depends on 3) The system of claim 3, wherein the processing circuitry is configured to determine the location of the ownship vehicle by constructing a geometry of signal arrivals at the at least three receivers. ### Claim 5 (depends on 1) The system of claim 1, wherein the processing circuitry is further configured to: determine the first time using a first clock for the first receiver; determine the second time using a second clock for the second receiver; and determine the third time using a third clock for the third receiver, wherein the first clock, the second clock, and the third clock are synchronized. ### Claim 6 (depends on 5) The system of claim 5, wherein the processing circuitry is further configured to synchronize the first clock, the second clock, and the third clock based on a Global Navigation Satellite System (GNSS) clock. ### Claim 7 (depends on 1) The system of claim 1, wherein the surveillance packet includes data indicating a transmission time of the surveillance packet, and wherein the processing circuitry is configured to determine a distance between the ownship vehicle and the other vehicle based on a time difference between the transmission time and one of the respective arrival times. ### Claim 8 (depends on 1) The system of claim 1, wherein the at least three receivers further comprises a fourth receiver configured to receive, at a fourth time, the surveillance packet from the other vehicle, wherein the processing circuitry is configured to determine the location of the ownship vehicle based on the received surveillance packet and the respective arrival times. ### Claim 9 (depends on 1) The system of claim 1, wherein the processing circuitry is configured to determine weather conditions between the ownship vehicle and the other vehicle based on: a determined distance from the ownship vehicle to the other vehicle; and a strength of surveillance signals received by one or more receivers of the at least three receivers from the other vehicle. ### Claim 10 (depends on 1) The system of claim 1, wherein the processing circuitry is configured to refine the determined location of the ownship vehicle based on a signal strength of the surveillance packet as received by the at least three receivers. ### Claim 11 (depends on 10) The system of claim 10, wherein the processing circuitry is configured to: determine weather conditions between the ownship vehicle and the other vehicle; determine an expected attenuation of the surveillance packet based on the weather conditions between the ownship vehicle and the other vehicle; and further refine the determined location of the ownship vehicle based on comparing the expected attenuation and the signal strength of the surveillance packet. ### Claim 12 (depends on 1) The system of claim 1, wherein the surveillance packet is a first surveillance packet transmitted from a first other vehicle, wherein the respective arrival times are a first set of arrival times, wherein the at least three receivers are configured to receive a second surveillance packet from a second other vehicle at a second set of arrival times, and wherein the processing circuitry is configured to determine the location of the ownship vehicle based on the first and second surveillance packets and the first and second sets of arrival times. ### Claim 13 (depends on 1) The system of claim 1, wherein the surveillance packet is a first surveillance packet transmitted from the other vehicle, wherein the respective arrival times are a first set of arrival times, wherein the at least three receivers are configured to receive a second surveillance packet from the other vehicle at a second set of arrival times, wherein the other vehicle has not traveled directly towards or away from the ownship vehicle between transmitting the first surveillance packet and transmitting the second surveillance packet, and wherein the processing circuitry is configured to determine the location of the ownship vehicle based on the first and second surveillance packets and the first and second sets of arrival times. ### Claim 14 (depends on 1) The system of claim 1, wherein the determined location of the ownship vehicle is a first estimated location of the ownship vehicle, wherein the processing circuitry is configured to determine a second estimate location of the ownship vehicle based on a Global Navigation Satellite System (GNSS), and wherein the processing circuitry is further configured to: compare the first estimated location and the second estimated location; and determine, in response to comparing the first and second estimated locations, that the GNSS has been spoofed or that the surveillance packet is a spoofed packet. ### Claim 15 A method comprising: receiving, by a first receiver mounted on an ownship vehicle at a first time, a surveillance packet from another vehicle; receiving, by a second receiver mounted on the ownship vehicle at a second time, the surveillance packet from the other vehicle; receiving, by a third receiver mounted on the ownship vehicle at a third time, the surveillance packet from the other vehicle; and determining a location of the ownship vehicle based on the received surveillance packet and based on the respective arrival times. ### Claim 16 (depends on 15) The method of claim 15, wherein determining the location of the ownship vehicle based on: a location of the other vehicle indicated by data in the received surveillance packet; and a time difference of arrival for the respective arrival times. ### Claim 17 (depends on 15) The method of claim 15, wherein determining the location of the ownship vehicle comprises performing a multilateration analysis based on: the respective arrival times; relative positions of the at least three receivers; and data from an inertial navigation system. ### Claim 18 A device comprising a computer-readable medium having executable instructions stored thereon, configured to be executable by processing circuitry for causing the processing circuitry to: determine a first time at which a first receiver mounted on an ownship vehicle received a surveillance packet from another vehicle; determine a second time at which a second receiver mounted on the ownship vehicle the surveillance packet from the other vehicle; determine a third time at which a third receiver mounted on the ownship vehicle the surveillance packet from the other vehicle; and determine a location of the ownship vehicle based on the received surveillance packet and based on the respective arrival times. ### Claim 19 (depends on 18) The device of claim 18, wherein the instructions for determining the location of the ownship vehicle comprise instructions for determining the location of the ownship vehicle based on: a location of the other vehicle indicated by data in the received surveillance packet; and a time difference of arrival for the respective arrival times. ### Claim 20 (depends on 18) The device of claim 18, wherein the surveillance packet includes data indicating a transmission time of the surveillance packet, and wherein the instructions are configured to be executable by the processing circuitry for further causing the processing circuitry to determine a distance between the ownship vehicle and the other vehicle based on a time difference between the transmission time and one of the respective arrival times.