# US 2017/0255204 A1 · Aircraft landing systems and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0255204 A1 - Document ID: US20170255204A1 - Status: Published application - Kind: A1 - Application number: 15/059,173 - Filed: 2016-03-02 - Published: 2017-09-07 - Earliest claimed: 2016-03-02 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Thomas E. Yochum - Web page: https://patentgrep.com/patent/US20170255204A1 ## CPC - G05D 1/0676: {specially adapted for landing} - B64C 19/00: Aircraft control not otherwise provided for - B64D 45/04: Landing aids; Safety measures to prevent collision with earth's surface - G01S 5/02521: {using a radio-map} - G01S 13/876: {Combination of several spaced transponders or reflectors of known location for determining the position of a receiver (G01S13/874 takes precedence)} - G01S 13/913: {for landing purposes} - G01S 13/953: {mounted on aircraft} - G05D 1/042: {specially adapted for aircraft} - H01Q 15/18: comprising plurality of mutually inclined plane surfaces, e.g. corner reflector {(H01Q15/16 takes precedence)} - Y02A 90/10: Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - B64C: AEROPLANES; HELICOPTERS - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN 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 - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE ## Abstract A method for controlling an aircraft includes storing data aboard the aircraft. The data include the relative positions of radar targets disposed within a region adjacent to the runway. The region is scanned with a radar aboard the aircraft to obtain data corresponding to the relative positions of radar reflections from the region, including reflections from the radar targets. The data corresponding to the radar targets is distinguished from the data corresponding to the radar reflections from the region using correlation techniques. The position and attitude of the aircraft relative to the runway is then assessed using the stored data and the data corresponding to the radar targets. The position and attitude of the aircraft relative to the runway is also evaluated using an independent navigation system. The difference between the assessed position and attitude and the evaluated position and attitude is then used to control the aircraft. ## Claims ### Claim 1 A method for controlling an aircraft, the method comprising: accessing data aboard the aircraft, the data including: respective positions, relative to each other and to a runway, of a plurality of radar targets disposed within a region adjacent to the runway; and a desired attitude of the aircraft relative to the runway; scanning the region with a radar disposed aboard the aircraft to obtain radar data corresponding to respective positions, relative to each other and to the aircraft, of a plurality of radar reflections from the region, including reflections from the radar targets; distinguishing the radar data corresponding to the radar targets from the radar data corresponding to the radar reflections; assessing a position and an attitude of the aircraft relative to the runway using the stored data and the radar data corresponding to the radar targets; evaluating the position and the attitude of the aircraft relative to the runway using a navigation system that is independent of the radar; computing a difference between the assessed position and the evaluated position; and computing a difference between the assessed attitude and the evaluated attitude. ### Claim 2 (depends on 1) The method of claim 1, wherein the radar comprises a weather radar. ### Claim 3 (depends on 1) The method of claim 1, wherein at least one of the radar targets comprises a dihedral or a trihedral radar reflector. ### Claim 4 (depends on 1) The method of claim 1 wherein the distinguishing comprises correlating the respective positions of the radar targets relative to each other, as obtained by the radar, with the respective positions of the radar targets relative to each other, as stored aboard the aircraft. ### Claim 5 (depends on 1) The method of claim 1, further comprising controlling the aircraft in accordance with at least one of the position difference and the attitude difference. ### Claim 6 (depends on 5) The method of claim 5, wherein the controlling comprises: adjusting a rectilinear movement of a center of gravity (CG) of the aircraft; and adjusting an angular movement of the aircraft about each of a pitch axis, a yaw axis and a roll axis of the aircraft. ### Claim 7 (depends on 5) The method of claim 5, wherein the controlling is effected by an autopilot disposed aboard the aircraft. ### Claim 8 (depends on 5) The method of claim 5, further comprising: displaying at least one of the assessed position and attitude and/or the evaluated position and attitude on a display disposed aboard the aircraft; and effecting the controlling manually using the display. ### Claim 9 (depends on 1) The method of claim 1, wherein the accessing further comprises: surveying the radar targets and the runway to obtain the data; and storing the data in a database of the aircraft. ### Claim 10 (depends on 1) The method of claim 1, further comprising at least one of: correcting the assessed position as a function of the position difference; and/or correcting the assessed attitude as a function of the attitude difference. ### Claim 11 A system for controlling an aircraft, the system comprising: a database disposed aboard the aircraft and storing data corresponding to: respective positions, relative to each other and to a runway, of a plurality of radar targets disposed within a region adjacent to the runway; and a desired attitude of the aircraft relative to the runway; a radar disposed aboard the aircraft and configured to scan, detect and generate data corresponding to respective positions, relative to each other and to the aircraft, of a plurality of radar reflections from the region, including reflections from the radar targets; a correlator disposed aboard the aircraft and configured to distinguish the radar data corresponding to the radar targets from the radar data corresponding to the radar reflections; and a navigation system disposed aboard the aircraft and configured to: assess a position and an attitude of the aircraft relative to the runway using the stored data and the radar data corresponding to the radar targets; evaluate the position and the attitude of the aircraft relative to the runway independently of the radar and using at least one of a global positioning system (GPS), an inertial navigation system (INS), a distance measuring equipment (DME) system, a very high frequency omnidirectional radio range (VOR) system, and/or an instrument landing system (ILS); compute a difference between the assessed position and the evaluated position; compute a difference between the assessed attitude and the evaluated attitude; and control the aircraft in accordance with at least one of the position and attitude differences. ### Claim 12 (depends on 11) The system of claim 11, wherein the correlator comprises: a computer; and an algorithm comprising a non-transitory machine-readable medium comprising a plurality of machine-readable instructions which, when executed by one or more processors of the computer, are configured to cause the computer to: correlate the respective positions of the radar targets relative to each other, as obtained by the radar, with the respective positions of the radar targets relative to each other, as stored aboard the aircraft; and distinguish the data corresponding to the radar targets from the data corresponding to the radar reflections. ### Claim 13 (depends on 11) The system of claim 11, wherein the radar comprises a weather radar. ### Claim 14 (depends on 11) The system of claim 11, further comprising an autopilot configured to control the aircraft in accordance with the difference. ### Claim 15 (depends on 11) The system of claim 11, further comprising a display configured to generate and present to a pilot of the aircraft a visual presentation of at least one of: the assessed position of the aircraft; the evaluated position of the aircraft; the assessed attitude of the aircraft; the evaluated attitude of the aircraft; the position difference; and/or the attitude difference. ### Claim 16 (depends on 14) The system of claim 14, wherein the display comprises a heads up display (HUD). ### Claim 17 (depends on 11) The system of claim 11, wherein the navigation system comprises a plurality of identical or substantially similar navigation systems operating redundantly. ### Claim 18 An apparatus for controlling an aircraft, the apparatus comprising: a radar disposed aboard the aircraft and configured to: scan a region surrounding a runway; and generate radar data corresponding to respective positions, relative to each other and the aircraft, of a plurality of radar reflections from the region; a correlator disposed aboard the aircraft and configured to: correlate the radar data with data stored aboard the aircraft, the stored data comprising respective positions, relative to each other and the runway, of a plurality of radar targets disposed within the region and a desired attitude of the aircraft relative to the runway; and distinguish the radar data corresponding to the radar targets from the radar data corresponding to the radar reflections; a navigation system disposed aboard the aircraft and configured to evaluate a position and an attitude of the aircraft relative to the runway independently of the radar; and a computer disposed aboard the aircraft and configured to: assess the position and the attitude of the aircraft relative to the runway using the radar data corresponding to the radar targets and the stored aircraft position and attitude data; and compute a difference between the assessed position and attitude of the aircraft and the evaluated position and attitude of the aircraft. ### Claim 19 (depends on 18) The apparatus of claim 18, further comprising a controller configured to control movement of the aircraft at least in part as a function of the difference. ### Claim 20 (depends on 18) The apparatus of claim 18, wherein the navigation system comprises at least one of a global positioning system (GPS), an inertial navigation system (INS), a distance measuring equipment (DME) system, a very high frequency omnidirectional radio range (VOR) system, and/or an instrument landing system (ILS).