# US 10,371,812 B2 · Ultra-wideband radar altimeter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,812 B2 - Document ID: US10371812B2 - Status: Granted - Kind: B2 - Application number: 15/440,796 - Filed: 2017-02-23 - Published: 2018-11-29 - Granted: 2019-08-06 - Earliest claimed: 2017-02-23 - Assignees: Rosemount Aerospace Inc. - Applicants: Rosemount Aerospace Inc. - Inventors: Joseph T. Pesik; Todd Anthony Ell - Web page: https://patentgrep.com/patent/US10371812B2 ## CPC - G01S 13/882: {for altimeters (measuring height using barometric means G01C5/06)} - B64U 60/50: with landing legs - G01S 7/032: {Constructional details for solid-state radar subsystems} - G01S 13/0209: {Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband} - G01S 13/10: using transmission of interrupted, pulse modulated waves (determination of distance by phase measurement G01S13/32) - B64U 10/14: with four distinct rotor axes, e.g. quadcopters - B64U 50/19: using electrically powered motors - B64U 2201/10: autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS] - G01S 7/027: {Constructional details of housings, e.g. form, type, material or ruggedness} - G01S 13/881: {for robotics} - G01S 13/933: of aircraft or spacecraft - G08G 5/55: for a single aircraft - G08G 5/57: for unmanned aircraft - H01Q 1/28: Adaptation for use in or on aircraft, missiles, satellites, or balloons - 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 - B64U: UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR - 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}) - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract A system can include an unmanned aerial vehicle and an altimeter disposed on the unmanned aerial vehicle. The altimeter can include an ultra-wideband radar antenna disposed orthogonally to a plane of straight and level flight of the unmanned aerial vehicle and having an omnidirectional azimuthal beam pattern orthogonal to the plane of straight and level flight of the unmanned aerial vehicle. The altimeter can be configured to determine an altitude of the unmanned aerial vehicle above a target surface based on time of flight of radar pulses between the ultra-wideband radar antenna and the target surface. ## Claims ### Claim 1 A system comprising: an unmanned aerial vehicle; and an altimeter disposed on the unmanned aerial vehicle, the altimeter including an ultra-wideband radar antenna disposed orthogonally to a plane of straight and level flight of the unmanned aerial vehicle and having an omnidirectional azimuthal beam pattern orthogonal to the plane of straight and level flight of the unmanned aerial vehicle, the altimeter configured to determine an altitude of the unmanned aerial vehicle above a target surface based on time of flight of radar pulses between the ultra-wideband radar antenna and the target surface; wherein the ultra-wideband radar antenna includes: a first major face having a width extending along a first axis and a length extending along a second axis that is perpendicular to the first axis; a second major face opposite the first major face, the second major face having the width extending along the first axis and the length extending along the second axis; and a thickness extending between the first major face and the second major face along a third axis that is orthogonal to both the first axis and the second axis; wherein the second axis is parallel to the plane of straight and level flight of the unmanned aerial vehicle; and wherein the omnidirectional azimuthal beam pattern circumscribes the first major face and the second major face about the second axis. ### Claim 2 (depends on 1) The system of claim 1, wherein the ultra-wideband radar antenna is a planar elliptical dipole antenna. ### Claim 3 (depends on 1) The system of claim 1, wherein a magnitude of attenuation of the omnidirectional azimuthal beam pattern of the ultra-wideband radar antenna is not greater than 10 decibels through an entire azimuthal span of the ultra-wideband radar antenna. ### Claim 4 (depends on 1) The system of claim 1, wherein the altimeter is configured to determine the altitude of the unmanned aerial vehicle above the target surface based on time of flight of radar pulses between the ultra-wideband radar antenna and the target surface by selecting a shortest round-trip time of flight of radar pulses emitted from the ultra-wideband radar antenna and received by the ultra-wideband radar antenna after reflection off the target surface. ### Claim 5 (depends on 1) The system of claim 1, wherein the altimeter is configured to determine the altitude of the unmanned aerial vehicle above the target surface based on time of flight of radar pulses between the ultra-wideband radar antenna and the target surface by selecting a shortest time of flight of radar pulses emitted from a remote ultra-wideband radar antenna disposed at the target surface. ### Claim 6 (depends on 5) The system of claim 5, wherein the altimeter is configured to receive communication data from the remote ultra-wideband radar antenna disposed at the target surface. ### Claim 7 (depends on 1) The system of claim 1, wherein the ultra-wideband radar antenna comprises a first ultra-wideband radar antenna configured to transmit radar pulses; and wherein the altimeter further includes a second ultra-wideband radar antenna configured to receive radar pulses. ### Claim 8 (depends on 1) The system of claim 1, wherein the ultra-wideband radar antenna is disposed on a flexible circuit board substrate that is mounted to a non-linear contoured surface of the unmanned aerial vehicle. ### Claim 9 (depends on 1) The system of claim 1, wherein the ultra-wideband radar antenna is disposed internally to the unmanned aerial vehicle. ### Claim 10 (depends on 1) The system of claim 1, wherein the ultra-wideband radar antenna is disposed on an external surface of the unmanned aerial vehicle. ### Claim 11 (depends on 1) The system of claim 1, wherein the altimeter is configured to transition from an inactive operational mode to an active operational mode in response to an activation command from a controller device of the unmanned aerial vehicle; wherein the altimeter refrains from causing the ultra-wideband radar antenna to transmit radar pulses during the inactive operational mode; and wherein the altimeter causes the ultra-wideband radar antenna to transmit the radar pulses during the active operational mode. ### Claim 12 (depends on 11) The system of claim 11, wherein the unmanned aerial vehicle initiates the activation command based on geographical position data of the unmanned aerial vehicle. ### Claim 13 (depends on 1) The system of claim 1, wherein the thickness is less than 0.1 inches; and wherein a surface area of each of the first major face and the second major face is less than 6 square inches. ### Claim 14 A method of determining an altitude of an unmanned aerial vehicle, the method comprising: receiving radar pulses at an ultra-wideband radar antenna of an altimeter disposed on the unmanned aerial vehicle; and determining the altitude of the unmanned aerial vehicle based on time of flight of the radar pulses between the ultra-wideband radar antenna and a target surface; wherein the ultra-wideband radar antenna is disposed orthogonally to a plane of straight and level flight of the unmanned aerial vehicle and has an omnidirectional azimuthal beam pattern orthogonal to the plane of straight and level flight of the unmanned aerial vehicle; wherein the ultra-wideband radar antenna includes: a first major face having a width extending along a first axis and a length extending along a second axis that is perpendicular to the first axis; a second major face opposite the first major face, the second major face having the width extending along the first axis and the length extending along the second axis; and a thickness extending between the first major face and the second major face along a third axis that is orthogonal to both the first axis and the second axis; wherein the second axis is parallel to the plane of straight and level flight of the unmanned aerial vehicle; and wherein the omnidirectional azimuthal beam pattern circumscribes the first major face and the second major face about the second axis. ### Claim 15 (depends on 14) The method of claim 14, further comprising: transmitting the radar pulses from the ultra-wideband radar antenna; wherein receiving the radar pulses at the ultra-wideband radar antenna comprises receiving the radar pulses after reflection off the target surface; and wherein determining the altitude of the unmanned aerial vehicle based on time of flight of the radar pulses between the ultra-wideband radar antenna and the target surface comprises selecting a shortest round-trip time of flight of the received radar pulses. ### Claim 16 (depends on 15) The method of claim 15, wherein the ultra-wideband radar antenna comprises a first ultra-wideband radar antenna; wherein the altimeter comprises a second ultra-wideband radar antenna; wherein transmitting the radar pulses from the ultra-wideband radar antenna comprises transmitting the radar pulses from the first ultra-wideband radar antenna; and wherein receiving the radar pulses at the ultra-wideband radar antenna after reflection off the target surface comprises receiving the radar pulses by the second ultra-wideband radar antenna. ### Claim 17 (depends on 14) The method of claim 14, wherein receiving the radar pulses at the ultra-wideband radar antenna comprises receiving the radar pulses transmitted from a remote ultra-wideband radar antenna disposed at the target surface; and wherein determining the altitude of the unmanned aerial vehicle based on time of flight of the radar pulses between the ultra-wideband radar antenna and the target surface comprises selecting a shortest time of flight of the received radar pulses transmitted from the remote ultra-wideband radar antenna. ### Claim 18 (depends on 14) The method of claim 14, further comprising: operating the altimeter in an inactive operational mode by refraining from causing the ultra-wideband radar antenna to transmit the radar pulses; receiving an activation command from a controller device of the unmanned aerial vehicle; and operating the altimeter in an active operational mode by causing the ultra-wideband radar antenna to transmit the radar pulses in response to receiving the activation command. ### Claim 19 (depends on 18) The method of claim 18, further comprising: initiating, by the controller device of the unmanned aerial vehicle, the activation command in response to determining that geographical position data of the unmanned aerial vehicle satisfies target position criteria.