WO2023097595A1 - 一种apnt服务的定位和完好性监测方法及系统 - Google Patents

一种apnt服务的定位和完好性监测方法及系统 Download PDF

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WO2023097595A1
WO2023097595A1 PCT/CN2021/134998 CN2021134998W WO2023097595A1 WO 2023097595 A1 WO2023097595 A1 WO 2023097595A1 CN 2021134998 W CN2021134998 W CN 2021134998W WO 2023097595 A1 WO2023097595 A1 WO 2023097595A1
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positioning
aircraft
altitude
dme
integrity monitoring
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PCT/CN2021/134998
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English (en)
French (fr)
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王志鹏
朱衍波
黄思琪
方堃
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北京航空航天大学
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Priority to PCT/CN2021/134998 priority Critical patent/WO2023097595A1/zh
Priority to US18/099,332 priority patent/US11747482B2/en
Priority to ZA2023/03851A priority patent/ZA202303851B/en
Publication of WO2023097595A1 publication Critical patent/WO2023097595A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/0205—Details
    • G01S5/0244—Accuracy or reliability of position solution or of measurements contributing thereto
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/13—Receivers
    • G01S19/14—Receivers specially adapted for specific applications
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
    • G01S13/76—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein pulse-type signals are transmitted
    • G01S13/765—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein pulse-type signals are transmitted with exchange of information between interrogator and responder
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
    • G01S13/76—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein pulse-type signals are transmitted
    • G01S13/78—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein pulse-type signals are transmitted discriminating between different kinds of targets, e.g. IFF-radar, i.e. identification of friend or foe
    • G01S13/785—Distance Measuring Equipment [DME] systems
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/86—Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/87—Combinations of radar systems, e.g. primary radar and secondary radar
    • G01S13/876—Combination of several spaced transponders or reflectors of known location for determining the position of a receiver
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/93—Radar or analogous systems specially adapted for specific applications for anti-collision purposes
    • G01S13/933—Radar or analogous systems specially adapted for specific applications for anti-collision purposes of aircraft or spacecraft
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/03—Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers
    • G01S19/08—Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers providing integrity information, e.g. health of satellites or quality of ephemeris data
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/38—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system
    • G01S19/39—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/396—Determining accuracy or reliability of position or pseudorange measurements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/01—Determining conditions which influence positioning, e.g. radio environment, state of motion or energy consumption
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/0257—Hybrid positioning
    • G01S5/0263—Hybrid positioning by combining or switching between positions derived from two or more separate positioning systems
    • G01S5/0264—Hybrid positioning by combining or switching between positions derived from two or more separate positioning systems at least one of the systems being a non-radio wave positioning system
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S2205/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S2205/01—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations specially adapted for specific applications
    • G01S2205/03—Airborne
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • 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
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/0257—Hybrid positioning
    • G01S5/0263—Hybrid positioning by combining or switching between positions derived from two or more separate positioning systems

Definitions

  • the invention relates to the technical field of aviation navigation, in particular to a positioning and integrity monitoring method and system for APNT services.
  • the Global Navigation Satellite System mainly includes the Global Positioning System (GPS) of the United States, the Global Navigation Satellite System (GLONASS) of Russia, and the Galileo Satellite Navigation System (Galileo) of Europe. Satellite Navigation System) and China's BeiDou Navigation Satellite System (BDS). With its high accuracy and high availability, GNSS has become the premier system for providing positioning, navigation and timing (Positioning, Navigation and Timing, PNT) services on a global scale.
  • GPS Global Positioning System
  • GLONASS Global Navigation Satellite System
  • Galileo Galileo Satellite Navigation System
  • BDS BeiDou Navigation Satellite System
  • GNSS signals are easily interrupted by radio frequency interference during the propagation process. If you only rely on the global satellite navigation system during the flight, it may cause the aircraft to lose navigation information after being interrupted by interference. , may cause flight accidents in severe cases.
  • INS inertial navigation systems
  • the existing navigation aid system must be used as a backup system to provide aircraft with alternative positioning, navigation and timing (Alternative Positioning, Navigation and Timing, APNT) services when GNSS is unavailable, so as to build an aviation navigation network and ensure the continuity of flight sex and integrity.
  • APNT Alternative Positioning, Navigation and Timing
  • the navigation aid system mainly includes distance measuring equipment (DME), VHF omnidirectional radio range (VHF Omnidirectional Radio Range, VOR), instrument landing system (Instrument Landing System, ILS), barometric altimeter and other navigation capabilities.
  • New systems such as L-band Digital Aeronautical Communication System (LDACS) and so on.
  • nextGen Next Generation Air Transportation System
  • SESAR Single European Sky ATM Research
  • solutions such as DME augmentation system, LDACS, SSR-based Mode N, and eLoran, etc.
  • DFMC Dual -Frequency Multi-Constellation
  • SESAR conducts research on the maturity of APNT services from three levels: short-term, medium-term and long-term.
  • the short-term research is mainly based on the DME/DME solution to realize the APNT service; the mid-term research is mainly based on the Multi-DME positioning algorithm with Receiver Autonomous Integrity Monitoring (RAIM) to realize the APNT service; the long-term goal is to pass
  • RAIM Receiver Autonomous Integrity Monitoring
  • the advanced architecture of LDAPS and eLORAN implements APNT services, can provide better performance, and supports Performance Based Navigation (PBN)/Required Navigation Performance (RNP) operations using alternative technologies.
  • Future APNT services will use existing navigation equipment and new navigation technologies for modular combination to achieve the goal of RNP0.3 in terminal mobile areas.
  • the purpose of the present invention is to provide a positioning and integrity monitoring method and system for APNT services, which can realize the integrity monitoring of APNT services under the premise of ensuring positioning accuracy.
  • the present invention provides the following scheme:
  • a method for positioning and integrity monitoring of APNT services comprising:
  • a combined positioning algorithm is used to determine the position of the aircraft, and a multi-solution separation method is used to monitor the integrity of the combined positioning;
  • the positioning accuracy requirement is low-precision positioning, determine whether the aircraft is a high-altitude user
  • LDACS-based air-to-air positioning algorithm for high-altitude users and low-altitude users to determine the position of the aircraft, and use the least squares residual method to monitor the integrity of the air-to-air positioning.
  • it also includes: when the aircraft is a high-altitude user, using a DME/DME-based positioning algorithm to determine the position of the aircraft, and performing integrity monitoring on the DME/DME-based positioning algorithm.
  • the integrity monitoring of the DME/DME-based positioning algorithm specifically includes:
  • the protection level is compared with the horizontal warning limit required by the route, so as to complete the integrity monitoring of the positioning algorithm based on DME/DME.
  • the air-to-air positioning algorithm of the LDACS-based high-altitude users and low-altitude users is used to determine the position of the aircraft, specifically including:
  • the position of the aircraft is determined according to the measured distance and the position information of the high-altitude user.
  • the air-to-air positioning integrity monitoring based on the least squares residual method specifically includes:
  • the fault detection threshold is calculated by the false detection probability of the system
  • a combined positioning algorithm to determine the position of the aircraft specifically includes:
  • the observation model is solved by using the least square method to determine the position of the aircraft.
  • the multi-solution separation method is used to monitor the integrity of the combined positioning, which specifically includes:
  • a positioning and integrity monitoring system for APNT services comprising:
  • a requirement determination module used to determine the positioning accuracy requirements in the target scene
  • the first positioning and integrity monitoring module is used to determine the position of the aircraft using a combined positioning algorithm when the positioning accuracy requirement is high-precision positioning, and perform integrity monitoring on the combined positioning in a multi-solution separation manner;
  • a judging module configured to judge whether the aircraft is a high-altitude user when the positioning accuracy requirement is low-precision positioning
  • the second positioning and integrity monitoring module is used to determine the position of the aircraft by using the air-to-air positioning algorithm of the high-altitude user and the low-altitude user based on LDACS when the aircraft is a low-altitude user, and use the least squares residual method based on the air-to-air positioning algorithm to determine the position of the aircraft. Empty positioning for integrity monitoring.
  • a third positioning and integrity monitoring module which is used to determine the position of the aircraft by using a positioning algorithm based on DME/DME when the aircraft is a high-altitude user, and perform the positioning algorithm based on DME/DME integrity monitoring.
  • the second positioning and integrity monitoring module specifically includes:
  • the high-altitude user location information unit is used to determine the location information of the high-altitude user by using the Multi-DME positioning algorithm
  • a measurement distance determining unit configured to determine the measurement distance between the high-altitude user and the low-altitude user based on the two-way ranging function of LDACS;
  • a position determining unit configured to determine the position of the aircraft according to the measured distance and the position information of the high-altitude user.
  • the invention discloses the following technical effects:
  • the invention provides a method and system for positioning and integrity monitoring of APNT services.
  • GNSS-based aviation navigation is interfered and the accuracy is reduced or even unavailable, according to the different needs of users for positioning accuracy and actual application conditions , provide multiple APNT alternatives for the aircraft, and conduct fault detection algorithm research for each alternative to realize the integrity monitoring of APNT services.
  • Fig. 1 is the schematic flow chart of the location of a kind of APNT service of the present invention and integrity monitoring method
  • Fig. 2 is the overall flow chart of the positioning and integrity monitoring method of a kind of APNT service of the present invention
  • Fig. 3 is a hierarchical structure diagram of the multi-solution separation method of the present invention.
  • Fig. 4 is the flow chart of the APNT integrity monitoring algorithm of multi-solution separation of the present invention.
  • FIG. 5 is a schematic structural diagram of an APNT service positioning and integrity monitoring system according to the present invention.
  • the most basic APNT method is based on DME/DME to achieve positioning, but this method requires the user to be able to continuously transmit information with a certain number of DME stations during the flight.
  • this method requires the user to be able to continuously transmit information with a certain number of DME stations during the flight.
  • some ground DME ranging sources may be blocked, which leads to a decrease in the positioning accuracy obtained by the user.
  • the number of ranging sources decreases To a certain extent, it will even cause APNT to be unavailable.
  • the present invention utilizes the high-altitude users who have obtained higher positioning accuracy through Multi-DME as an airborne ranging source according to the two-way ranging function of LDACS, and provides position information for low-altitude users, similar to the pseudo-range measurement in GNSS Realize positioning, and realize air-to-air co-location integrity monitoring based on the least squares residual algorithm, and use the minimum detectable fault to further calculate the protection level of the system.
  • the positioning accuracy that this method can provide is limited.
  • the present invention proposes a positioning method combining DME, LDACS and barometric altimeter, by combining the three observations of distance measurement, pseudorange measurement and height measurement, and utilizing the residual error minimization algorithm to realize positioning, This method can provide users with higher positioning accuracy.
  • RNP requires airborne equipment to have on-board performance monitoring and alerting capabilities (On-Board Performance Monitoring and Alerting, OPMA), and DME/DME positioning may not support this RNP navigation specification. Therefore, the concept of On-Ground Performance Monitoring and Alerting (GPMA) based on RNP is proposed, which is similar to the RAIM algorithm commonly used in GNSS to monitor the integrity of DME/DME systems.
  • GPMA On-Ground Performance Monitoring and Alerting
  • the integrity monitoring is mainly carried out through redundant measurement.
  • the invention builds a systematic observation model, and uses the method of multi-solution separation to realize the monitoring and isolation of APNT faults.
  • the present invention provides a method and system for positioning and integrity monitoring of APNT services, which realize integrity monitoring of APNT services on the premise of improving positioning accuracy.
  • the positioning of high-altitude users is realized through Multi-DME, and the air-to-air co-location between high-altitude users and low-altitude users is realized based on the two-way ranging function of LDACS.
  • a method for positioning and integrity monitoring of an APNT service includes the following steps.
  • Step 101 Determine the positioning accuracy requirements in the target scene; the target scene is a scene when GNSS is unavailable.
  • Step 102 When the positioning accuracy requirement is high-precision positioning, use a combined positioning algorithm to determine the position of the aircraft, and use a multi-solution separation method to monitor the integrity of the combined positioning.
  • Step 103 When the positioning accuracy requirement is low-precision positioning, determine whether the aircraft is a high-altitude user; if not, execute step 104; if yes, execute step 105.
  • Step 104 Using the LDACS-based air-to-air positioning algorithm for high-altitude users and low-altitude users to determine the position of the aircraft, and using the least squares residual method to monitor the integrity of the air-to-air positioning.
  • Step 105 When the aircraft is a high-altitude user, use a DME/DME-based positioning algorithm to determine the position of the aircraft, and perform integrity monitoring on the DME/DME-based positioning algorithm.
  • step 105 specifically includes:
  • DME refers to the range finder, which is a distance measuring device widely used in aviation navigation. It consists of an airborne interrogator and a ground transponder. When working, the interrogator sends an interrogation signal, and the responder transmits a response synchronously with the interrogation signal in sequence. In this way, the DME system can measure the slant distance between the aircraft and the ground station. A single DME station cannot realize the positioning of the aircraft, and the position of the aircraft can only be determined when two or more DME station signals are received at the same time.
  • DME/DME is one of the main ways to support Regional Area Navigation (RNAV), and its positioning accuracy is inferior to GNSS.
  • RNAV Regional Area Navigation
  • DME/DME Integrity Monitoring Algorithm specifically including: calculating the position of the aircraft before introducing the new measuring station and the position of the aircraft after introducing the new measuring station; based on the position of the aircraft before introducing the new measuring station and the introduced Calculate the protection level of the positioning algorithm based on DME/DME based on the aircraft position after the new station measurement; compare the protection level with the horizontal warning limit required by the route to complete the integrity of the positioning algorithm based on DME/DME monitoring; the detailed process is as follows:
  • the DME signal may be subject to two threats during the propagation process. On the one hand, it may be affected by the terrain to produce multipath effects, resulting in errors in ranging information. On the other hand, the signal may be interfered by other signals on the same channel, resulting in signal reception. mistake.
  • the former can be improved by changing the signal waveform and the echo suppression mechanism, while the latter requires frequency allocation and compatibility research on the signal.
  • the present invention unifies it as a transponder failure, which will be reflected in the positional deviation of the DME station, causing the mean value of the DME error distribution to be non-zero.
  • the position is calculated based on two DME stations i and j, and the horizontal position error is obtained:
  • Design a single fault scenario Assume that the aircraft obtains the initial effective position through two non-faulty DME stations, and as the position of the aircraft changes, the initial two stations no longer meet the geometric conditions, and a new station DME3 needs to be introduced to one of the initial When the measurement station is replaced, the Flight Management System (FMS) compares the position of the aircraft before the introduction of the new measurement station with the position after the introduction, determines the potential ranging deviation, and then calculates the protection level of the position solution scheme.
  • FMS Flight Management System
  • test statistic R R 12 -R 3 , where If DME3 has no faults, the test statistic R obeys N(0, ⁇ R ), and the fault detection threshold T can be obtained from the false detection probability P fd :
  • test statistic R obeys N( ⁇ , ⁇ R ), and the minimum detectable deviation ⁇ m is obtained from the missed detection probability P md and the detection threshold T:
  • the air-to-air positioning algorithm of the LDACS-based high-altitude users and low-altitude users is used to determine the position of the aircraft, specifically including:
  • Multi-DME positioning algorithm uses the Multi-DME positioning algorithm to determine the location information of the high-altitude user; based on the two-way ranging function of LDACS, determine the measurement distance between the high-altitude user and the low-altitude user; determine the low-altitude user according to the measurement distance and the location information of the high-altitude user the position of the aircraft.
  • high-altitude users can obtain ranging information and ranging error information from more ground ranging sources, such as achieving accurate positioning through the Multi-DME method, and broadcast their position to low-altitude users as an airborne ranging source Information and covariance matrix, combined with the air-to-air communication capability of LDACS, realizes the distance measurement between high-altitude users and low-altitude users, and low-altitude users can obtain their own positions.
  • ranging information and ranging error information from more ground ranging sources, such as achieving accurate positioning through the Multi-DME method
  • broadcast their position to low-altitude users as an airborne ranging source Information and covariance matrix combined with the air-to-air communication capability of LDACS, realizes the distance measurement between high-altitude users and low-altitude users, and low-altitude users can obtain their own positions.
  • the altitude measurement is assisted by the barometric altimeter.
  • Air-to-air measurement is carried out according to the position measurement y A of the high-altitude user ranging source A, and its position error ⁇ A obeys the distribution N(0, ⁇ A ).
  • the distance between the low-altitude user and the airborne ranging source n is:
  • r (n) (x u -x (n) ) ⁇ 1 (n) + T (n) + M (n) + c ⁇ (dt (n) - dt u ) + ⁇ (n) (10);
  • x u and x (n) are the positions of the aircraft and the ranging source
  • ⁇ (n) is the ranging error
  • T (n) is the tropospheric delay
  • M (n) is the multipath effect
  • dt (n) is the aircraft
  • dt u represents the clock offset of the user receiver
  • 1 (n) is a group of unit vectors along the direction of the connecting line between the user receiver and the ranging source, which is called the line-of-sight ( Light of Sight, LoS) vector.
  • the tropospheric delay T (n) and the effect of multipath M (n) are negligible since they usually only cause random errors a few orders of magnitude smaller than ⁇ r .
  • the pseudo-range measurement between the airborne ranging source and the low-altitude user is realized through the two-way ranging function of LDACS:
  • t t and t r represent the time when the low-altitude user transmits and receives the signal, respectively, ⁇ represents the known inherent delay between the receiving signal and the transmitting response signal of the high-altitude ranging source, and c represents the speed of light.
  • the airborne ranging source is different from the satellite or the ground ranging source, and its position itself has a non-negligible uncertainty, which can be regarded as the ephemeris error in the satellite, which is determined by the noise ⁇ in the distance measurement r is added to the uncertainty of the airborne ranging source along the LoS, and the ranging error ⁇ (n) at the low-altitude user j can be approximated as a zero-mean Gaussian distribution N(0, ⁇ n,j ), where:
  • ⁇ n represents the error covariance matrix of positioning by the position of the ranging source, which is related to the position uncertainty of the ranging source itself, and reflects the accuracy of the distance measurement value obtained from the ranging source signal. Since the airborne ranging source is positioned through Multi-DME, its positioning accuracy can be expressed as:
  • G is a geometric matrix composed of line-of-sight unit vectors, which is related to the geometric position of the ranging source relative to the user
  • W is a weighted matrix reflecting the ranging error caused by each ranging source
  • its diagonal elements ⁇ r i is the ranging correction obtained in the iterative process.
  • Air-to-air co-location integrity monitoring based on the least squares residual method including:
  • Air-to-air co-location can achieve integrity monitoring through the least squares residual method.
  • the position estimate that minimizes the sum of squares of ranging errors is obtained by the least square method:
  • the ranging residual vector is expressed as:
  • Air-to-air co-location introduces a new failure mode, which may lead to new potential integrity risks. Similar to the ephemeris failure in satellite navigation, in air-to-space co-location, the position broadcast of the airborne ranging source may have a failure ⁇ x, which will be reflected in the ranging error through the line-of-sight vector:
  • r (n) (x u -(x (n) + ⁇ x)) ⁇ 1 (n) +c ⁇ (dt (n) -dt u )+ ⁇ (n) (21);
  • r (n) (x u - x (n) ) ⁇ 1 (n) + ⁇ r (n) + c ⁇ (dt (n) - dt u ) + ⁇ (n) (22);
  • the error ⁇ r caused by the ranging fault causes the pseudo-range residual vector to change, and the mean value of the ranging error corresponding to the location of the fault-ranging source in the vector is no longer zero, which makes the norm of the pseudo-range residual vector Obey the non-central ⁇ 2 distribution, the non-central parameter is ⁇ r 2 :
  • the fault detection threshold T D is calculated by the false detection probability P fd of the system:
  • the horizontal protection level needs to be calculated. From the horizontal precision factor HDOP of the geometric configuration of the airborne ranging source and the horizontal precision factor HDOP i after removing the i-th ranging source, the variation of the horizontal precision factor ⁇ HDOP i is obtained:
  • the horizontal protection level of the system is calculated from the minimum detectable fault Er and the HDOP (horizontal precision factor) of the system:
  • HPL ⁇ HDOP max x ⁇ A x E r (27).
  • the use of a combined positioning algorithm to determine the position of the aircraft specifically includes:
  • the APNT algorithm based on DME/DME or LDACS can provide basic PNT functions for users in different airspaces, and combined with the integrity monitoring algorithm above, it can provide users with the required navigation performance.
  • multiple positioning methods can be combined to improve redundant measurements, such as combining DME, LDACS and barometric altimeter measurements, based on the residual error minimization algorithm
  • the algorithm block diagram is shown in Figure 3.
  • the DME provides two-way distance measurement
  • LDACS provides one-way pseudo-range measurement
  • the barometric altimeter provides altitude information by measuring air pressure. Higher-precision positioning is achieved by combining measurement information from each system.
  • the ranging error obtained by two-way ranging from m DME stations is:
  • ⁇ i represents the distance measured by the i-th DME station
  • s i is the position of the i-th DME station
  • the pseudorange error obtained by one-way measurement of n LDACS stations is:
  • ⁇ Lj represents the pseudorange measured by the j-th LDACS station
  • s Lj is the position of the j-th LDACS station
  • dt is the clock bias.
  • y is the observation quantity, that is, the difference between the distance measurement and the approximate calculation distance
  • G is the observation matrix
  • a i,j are the coefficients of the observation matrix
  • x is the three position errors in the earth coordinate system ( ⁇ x , ⁇ y, ⁇ z) and the receiver clock bias dt to be estimated state quantities
  • ⁇ D is an m ⁇ 1 order vector
  • ⁇ L is an n ⁇ 1 order vector, which respectively represent the propagation uncertainties in the ranging process of DME and LDACS
  • the ranging bias vectors brought about by the influence of sex and receiver noise, etc., and their standard deviations are ⁇ D and ⁇ L , respectively.
  • a is the major radius of the reference ellipsoid
  • e is the oblate heart rate of the ellipsoid.
  • the ranging error in the geographic coordinate system can be obtained, which is expressed as:
  • ⁇ , ⁇ and h represent latitude, longitude and height respectively, and A represents the coordinate transformation matrix.
  • H B is the barometric altitude
  • ⁇ B represents the measurement error of the barometric altimeter, which obeys the zero-mean Gaussian distribution, and its standard deviation is ⁇ B .
  • Z represents the observation information, including the observations of DME, LDACS and barometric altimeter
  • H represents the observation matrix
  • X represents the state quantity, including the three position errors in the geographic coordinate system and the equivalent measurement of the receiver clock difference.
  • distance error V is the measurement noise matrix, its mean value is 0, and the variance matrix is AG is a matrix of order n ⁇ 4, which represents the observation matrix of the navigation system obtained after the coordinate transformation of the observation matrix G.
  • equation (32) has a unique solution: ⁇ 1 , ⁇ 1 , ⁇ h 1 , which are superimposed on the initial position ⁇ 0 , ⁇ 0 , h 0 to obtain the next approximate position , replace the initial position into equation (32) and iterate until ⁇ i , ⁇ i , ⁇ h i reach the required magnitude, and then the least squares solution of the user position in the geographic coordinate system can be obtained.
  • the integrity monitoring of APNT is realized by using the method of multi-solution separation. Define the estimate obtained by using all observations as the main estimate, and the estimate obtained after excluding one observation as the sub-estimate. Set the fault threshold, and realize the monitoring and isolation of APNT faults by comparing the difference between different estimates with the set threshold.
  • the state master estimate under the full observation quantity can be obtained:
  • Q 0 is the least squares solution matrix under the complete observation condition
  • the dimension is 4 ⁇ (m+n+1) order.
  • Q' i represents the 4 ⁇ (m+n) order least squares solution matrix under the condition of incomplete observation after excluding the i-th distance observation.
  • Q' i is expanded to a 4 ⁇ (m+n+1) order matrix Q i , and the sub-estimation is obtained:
  • the fault judgment is based on:
  • the processing process is similar to the fault detection process. It is necessary to calculate the test statistic d i,j and the detection threshold T i,j first, and then make a judgment to determine the nth ranging
  • the basis for a faulty source is: if there is one and only one sub-estimator X n and the test statistics X n,j of all its sub-estimators are smaller than the fault detection threshold, then the nth ranging source needs to be isolated.
  • VPL Vertical Protection Level
  • the HPL i corresponding to each sub-estimation X i consists of two parts: one is the threshold for separating the sub-estimation X i from the main estimate X 0 , that is, the fault detection threshold T i calculated by the false detection probability P fd ; the other is The sub-estimates its own horizontal position error threshold a i , namely:
  • the vertical protection level of the multi-solution separation method can be calculated:
  • a positioning and integrity monitoring system for APNT services provided by this embodiment includes:
  • a requirement determination module 501 configured to determine the positioning accuracy requirement in the target scenario.
  • the first positioning and integrity monitoring module 502 is configured to determine the position of the aircraft using a combined positioning algorithm when the positioning accuracy requirement is high-precision positioning, and perform integrity monitoring on the combined positioning in a multi-solution separation manner.
  • a judging module 503 configured to judge whether the aircraft is a high-altitude user when the positioning accuracy requirement is low-precision positioning.
  • the second positioning and integrity monitoring module 504 is used to determine the position of the aircraft by using the air-to-air positioning algorithm of the high-altitude user and the low-altitude user based on LDACS when the aircraft is a low-altitude user, and use the least squares residual method based on the air-to-air positioning algorithm to determine the position of the aircraft. Integrity monitoring of empty positioning.
  • the third positioning and integrity monitoring module 505 is used to determine the position of the aircraft by using a positioning algorithm based on DME/DME when the aircraft is a high-altitude user, and perform integrity monitoring on the positioning algorithm based on DME/DME.
  • the second positioning and integrity monitoring module specifically includes:
  • the high-altitude user location information unit is used to determine the location information of the high-altitude user by using the Multi-DME positioning algorithm.
  • the measurement distance determining unit is used for determining the measurement distance between the high-altitude user and the low-altitude user based on the two-way ranging function of LDACS.
  • a position determining unit configured to determine the position of the aircraft according to the measured distance and the position information of the high-altitude user.
  • the present invention proposes a classification method according to the user's demand for positioning accuracy and actual application conditions, and provides three different APNT algorithms in consideration of the characteristics of various situations;
  • observation equation obtained by the combination of DME/LDACS is transformed into the geographic coordinate system through coordinate conversion and combined with the altitude observation provided by the barometric altimeter to obtain the combined observation equation
  • the method is used to solve the positioning by the least square method
  • a method for calculating APNT horizontal and vertical protection levels based on the covariance matrix of the difference between the main estimate and the sub-estimation obtained from the combined state equation of DME/LDACS/barometric altimeter and the system's false detection probability and false alarm probability is proposed.
  • the present invention provides multiple APNT alternatives to the aircraft, providing a solution to the positioning problem of the aircraft when GNSS is not available;
  • the present invention provides a relative positioning method for low-altitude users who are blocked by terrain or buildings based on the two-way ranging function of LDACS;
  • the present invention proposes the method that utilizes DME/LDACS/pneumatic altimeter to carry out combined positioning, further improves the positioning accuracy of APNT;
  • the present invention provides a fault detection algorithm suitable for each positioning algorithm in order to realize the integrity monitoring of APNT, and proves the availability of the algorithm by calculating the protection level;
  • the present invention helps to increase the importance of APNT in China, and promotes the promotion and application of its algorithm.
  • each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.
  • the description is relatively simple, and for the related information, please refer to the description of the method part.

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Abstract

一种APNT服务的定位和完好性监测方法及系统，方法包括：确定目标场景下的定位精度需求（101）；当定位精度需求为高精度定位时，采用组合定位算法确定航空器的位置，并采用多解分离方式对组合定位进行完好性监测（102）；当定位精度需求为低精度定位时，判断航空器是否为高空用户（103）；若否，则采用基于LDACS的高空用户与低空用户的空对空定位算法确定航空器的位置，并采用基于最小二乘残差法对空对空定位进行完好性监测（104）。能够根据用户对定位精度的不同需求和实际的应用条件，为航空器提供多种APNT备选方案，并针对各个备选方案进行故障检测算法研究，实现APNT服务的完好性监测。

Description

一种APNT服务的定位和完好性监测方法及系统 技术领域
本发明涉及航空导航技术领域，特别是涉及一种APNT服务的定位和完好性监测方法及系统。
背景技术
航空运输系统的现代化对航空导航系统的性能提出了更高的要求。全球卫星导航系统(Global Navigation Satellite System，GNSS)主要包括美国的全球定位系统(Global Positioning System，GPS)、俄罗斯的全球卫星导航系统(Global Navigation Satellite System，GLONASS)、欧洲的伽利略卫星导航系统(Galileo Satellite Navigation System)以及中国的北斗卫星导航系统(BeiDou Navigation Satellite System，BDS)。凭借其高精度和高可用性，GNSS成为全球范围内提供定位、导航和授时(Positioning，Navigation and Timing，PNT)服务的首要系统。
然而，GNSS信号功率低、传播距离远，故GNSS信号在传播过程中极易受到射频干扰而造成中断，若在飞行过程中仅依靠全球卫星导航系统，可能会导致航空器受干扰中断后丢失导航信息，严重时可能造成飞行事故。而作为仅次于GNSS的常用导航系统，惯性导航系统(Inertial Navigation Systems，INS)的误差会随着时间累加，其使用在时间上受到一定的限制。因此，必须利用现有的导航辅助系统作为备份系统，在GNSS不可用时，为航空器提供备用定位、导航和授时(Alternative Positioning，Navigation and Timing，APNT)服务，从而构建航空导航网络，保证飞行的连续性和完好性。
导航辅助系统主要包括测距仪(Distance Measuring Equipment，DME)、甚高频全向信标(VHF Omnidirectional Radio Range，VOR)、仪表着陆系统(Instrument Landing System，ILS)、气压式高度表以及其他具有导航能力的新型系统，例如L频段数字航空通信系统(L-band Digital Aeronautical Communication System，LDACS)等。
目前，美国的下一代航空运输系统(Next Generation Air Transportation System，NextGen)以及欧洲的单一天空空中交通管理研究项目(Single European Sky ATM Research，SESAR)都针对APNT服务开展研究，并提出了一些备选方案(例如DME增强系统，LDACS，基于SSR的模式N以及eLoran等)，但仍然需要进一步进行研究以确定如何以可持续的方式在这些方案中进行选择，同时又不给双频多星座(Dual-Frequency Multi-Constellation，DFMC)GNSS的实施带来风险。SESAR针对APNT服务的成熟程度，从短期、中期和长期三个层面开展研究。其中，短期研究主要基于DME/DME解决方案实现APNT服务；中期研究主要基于带有接收机自主完好性监测(Receiver Autonomous Integrity Monitoring，RAIM)的Multi-DME定位算法实现APNT服务；长期目标则计划通过LDACS和eLORAN的高级体系结构实现APNT服务，能够提供更好的性能，并使用替代技术支持基于性能的导航(Performance Based Navigation，PBN)/所需导航性能(Required Navigation Performance，RNP)操作。未来的APNT服务将利用现有的导航设备和新型导航技术进行模块化组合，在终端移动区域实现RNP0.3的目标。
APNT服务的发展面临诸多问题，其中，定位精度的提高和完好性监测是最亟待解决的。
发明内容
本发明的目的是提供一种APNT服务的定位和完好性监测方法及系统，在保证定位精度的前提下，实现APNT服务的完好性监测。
为实现上述目的，本发明提供了如下方案：
一种APNT服务的定位和完好性监测方法，包括：
确定目标场景下的定位精度需求；
当所述定位精度需求为高精度定位时，采用组合定位算法确定航空器的位置，并采用多解分离方式对组合定位进行完好性监测；
当所述定位精度需求为低精度定位时，判断航空器是否为高空用户；
若否，则采用基于LDACS的高空用户与低空用户的空对空定位算法确定 航空器的位置，并采用基于最小二乘残差法对空对空定位进行完好性监测。
可选的，还包括：当所述航空器为高空用户时，采用基于DME/DME的定位算法确定航空器的位置，并对基于DME/DME的定位算法进行完好性监测。
可选的，所述对基于DME/DME的定位算法进行完好性监测，具体包括：
计算引入新的测站前的航空器位置与引入新的测站后的航空器位置；
基于所述引入新的测站前的航空器位置和所述引入新的测站后的航空器位置，计算所述基于DME/DME的定位算法的保护级；
将所述保护级与航路所要求的水平告警限进行比较，以完成基于DME/DME的定位算法的完好性监测。
可选的，所述采用基于LDACS的高空用户与低空用户的空对空定位算法确定航空器的位置，具体包括：
采用Multi-DME定位算法，确定高空用户的位置信息；
基于LDACS的双向测距功能，确定所述高空用户与低空用户之间的测量距离；
根据所述测量距离、高空用户的位置信息，确定航空器的位置。
可选的，所述采用基于最小二乘残差法对空对空定位进行完好性监测，具体包括：
通过系统的误检概率计算故障的检测阈值；
根据所述检测阈值和漏检概率计算最小可检测故障；
计算系统的水平精度因子；
由所述最小可检测故障和所述水平精度因子计算系统的水平保护级；
基于水平保护级，完成空对空定位的完好性监测。
可选的，所述采用组合定位算法确定航空器的位置，具体包括：
计算由m个DME站进行双向测距得到的测距误差以及由n个LDACS站单向测量得到的伪距误差；
基于所述测距误差和所述伪距误差，构建测距系统的观测方程；
取气压高度作为观测量，将气压升高度表引入系统中，得到高度观测方程；
基于所述观测方程和所述高度观测方程，构建系统的观测模型；
采用最小二乘法对所述观测模型进行求解，确定航空器的位置。
可选的，所述采用多解分离方式对组合定位进行完好性监测，具体包括：
基于所述系统的观测模型，计算状态主估计和状态子估计；
基于所述状态主估计和所述状态子估计，计算差值协方差矩阵；
基于所述差值协方差矩阵，构建水平位置检验统计量；
根据所述误检概率计算故障的检测阈值；
根据所述检验统计量和所述检测阈值，确定是否有故障；
若是有故障，则对所述故障进行隔离，并计算系统的保护级；
若是无故障，则直接计算系统的保护级；
根据所述保护级，完成组合定位的完好性监测。
一种APNT服务的定位和完好性监测系统，包括：
需求确定模块，用于确定目标场景下的定位精度需求；
第一定位和完好性监测模块，用于当所述定位精度需求为高精度定位时，采用组合定位算法确定航空器的位置，并采用多解分离方式对组合定位进行完好性监测；
判断模块，用于当所述定位精度需求为低精度定位时，判断航空器是否为高空用户；
第二定位和完好性监测模块，用于当航空器为低空用户时，采用基于LDACS的高空用户与低空用户的空对空定位算法确定航空器的位置，并采用基于最小二乘残差法对空对空定位进行完好性监测。
可选的，还包括：第三定位和完好性监测模块，用于当所述航空器为高空用户时，采用基于DME/DME的定位算法确定航空器的位置，并对基于DME/DME的定位算法进行完好性监测。
可选的，在所述采用基于LDACS的高空用户与低空用户的空对空定位算法确定航空器的位置方面，所述第二定位和完好性监测模块，具体包括：
高空用户位置信息单元，用于采用Multi-DME定位算法，确定高空用户的位置信息；
测量距离确定单元，用于基于LDACS的双向测距功能，确定所述高空用户与低空用户之间的测量距离；
位置确定单元，用于根据所述测量距离、高空用户的位置信息，确定航空器的位置。
根据本发明提供的具体实施例，本发明公开了以下技术效果：
本发明提供了一种APNT服务的定位和完好性监测方法及系统，在基于GNSS的航空导航受干扰而造成精度下降甚至不可用的情况下，根据用户对定位精度的不同需求和实际的应用条件，为航空器提供多种APNT备选方案，并针对各个备选方案进行故障检测算法研究，实现APNT服务的完好性监测。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动性的前提下，还可以根据这些附图获得其他的附图。
图1为本发明一种APNT服务的定位和完好性监测方法的流程示意图；
图2为本发明一种APNT服务的定位和完好性监测方法的整体流程图；
图3为本发明多解分离法层次结构图；
图4为本发明多解分离的APNT完好性监测算法的流程图；
图5为本发明一种APNT服务的定位和完好性监测系统的结构示意图。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
最基础的APNT方法是基于DME/DME实现定位，但这种方法要求用户在飞行过程中能够不间断的与一定数量的DME台站进行信息传输。然而，对于飞行高度较低的航空器来说，受到地形和城市环境的影响，部分地面DME测距源可能存在被遮挡的情况，这导致用户解算得到的定位精度下降，当测距源数量下降到一定程度时甚至会导致APNT不可用。针对这一问题，本发明根据LDACS的双向测距功能，利用通过Multi-DME获得较高定位精度的高空用户作为机载测距源，为低空用户提供位置信息，类似于GNSS中通过测伪距实现定位，并基于最小二乘残差算法实现空对空协同定位完好性监测，利用最小可检测故障进一步计算出系统的保护级。然而，对于具有更高定位精度要求的用户来说，这种方法能够提供的定位精度是有限的。针对这一问题，本发明提出了利用DME、LDACS以及气压式高度表相结合的定位方法，通过组合测距、测伪距和测高这三种观测量，利用残差最小化算法实现定位，这种方法能够为用户提供更高的定位精度。
APNT面临的另一个重要问题是完好性监测问题。RNP要求机载设备必须具有机载性能监视和告警能力(On-Board Performance Monitoring and Alerting，OPMA)，而DME/DME定位可能不支持这种RNP导航规范。由此提出基于支持RNP的地面性能监视和告警(On-Ground Performance Monitoring and Alerting，GPMA)概念，类似于GNSS中常用的RAIM算法，为DME/DME系统进行完好性监测。对于DME、LDACS以及气压式高度表相结合的定位方法，主要通过冗余测量进行完好性监测，本发明构建了系统的观测模型，并采用多解分离的方法实现APNT故障的监测与隔离。
鉴于此，本发明提供了一种APNT服务的定位和完好性监测方法及系统，在提高定位精度的前提下，实现APNT服务的完好性监测。
为使本发明的上述目的、特征和优点能够更加明显易懂，下面结合附图和具体实施方式对本发明作进一步详细的说明。
本发明的目的主要通过以下技术方案实现：
1、通过DME/DME实现高空用户的准确定位与精度估计。
2、确定DME/DME定位中引入的故障模式，计算其对应的位置偏差，通过引入新的测站实现故障检测，计算系统保护级，同时将保护级与告警限相比较，判断系统的可用性。
3、通过Multi-DME实现高空用户的定位，基于LDACS的双向测距功能实现高空用户与低空用户之间的空对空协同定位。
4、确定基于LDACS的空对空协同定位中引入的故障模式，针对其特性设计故障检测算法，对定位误差的残差进行建模，计算系统保护级。
5、组合DME/LDACS/气压式高度表，利用最小二乘法实现用户的高精度定位。
6、采用多解分离算法实现组合定位的完好性监测，计算全集和各对应子集的定位误差，实现APNT故障的检测和排除，计算系统保护级，判断系统可用性。
实施例一
如图1和图2所示，本实施例提供的一种APNT服务的定位和完好性监测方法，包括如下步骤。
步骤101：确定目标场景下的定位精度需求；所述目标场景为GNSS不可用时的场景。
步骤102：当所述定位精度需求为高精度定位时，采用组合定位算法确定航空器的位置，并采用多解分离方式对组合定位进行完好性监测。
步骤103：当所述定位精度需求为低精度定位时，判断航空器是否为高空用户；若否，则执行步骤104；若是，则执行步骤105。
步骤104：采用基于LDACS的高空用户与低空用户的空对空定位算法确定航空器的位置，并采用基于最小二乘残差法对空对空定位进行完好性监测。
步骤105：当所述航空器为高空用户时，采用基于DME/DME的定位算法确定航空器的位置，并对基于DME/DME的定位算法进行完好性监测。
其中，步骤105具体包括：
1、基于DME/DME的定位原理
DME指测距仪，是一种广泛应用于航空导航的测距设备，由机载端的询问器和地面的应答器组成。工作时，询问器发送询问信号，应答器按次序传送与询问信号同步的应答。通过这种方式，DME系统可以测量航空器与地面台之间的斜距。单个DME台无法实现航空器的定位，同时收到两个或两个以上DME台信号时才能确定航空器的位置。
在基于DME/DME的定位原理进行定位时，航空器必须位于DME台的覆盖范围之内，并能够同时接收至少两个DME台站的输入信号。如果仅能收到两个DME台站的输入，航空器与两个DME台站连线的夹角必须在30度和150度之间。DME/DME是支持区域导航(Regional Area Navigation，RNAV)的主要方式之一，其定位精度次于GNSS。
2、DME/DME完好性监测算法，具体包括：计算引入新的测站前的航空器位置与引入新的测站后的航空器位置；基于所述引入新的测站前的航空器位置和所述引入新的测站后的航空器位置，计算所述基于DME/DME的定位算法的保护级；将所述保护级与航路所要求的水平告警限进行比较，以完成基于DME/DME的定位算法的完好性监测；详细过程如下：
DME信号在传播过程中可能会受到两种威胁，一方面是可能会受地形影响产生多径效应，造成测距信息错误，另一方面是信号可能遭受到同信道其他信号的干扰造成信号的接收错误。前者可以通过信号波形的改变以及回波抑制机制得到改善，后者需要对信号进行频率分配和兼容性研究。在这里本发明将其统一为应答器故障，该故障将反映在DME站的位置偏差中，造成DME误差分布的平均值非零。
假定DME误差服从正态分布，无故障应答器误差的平均值为零，故障应答器的平均值等于台站偏差：
Figure PCTCN2021134998-appb-000001
其中，
Figure PCTCN2021134998-appb-000002
指DME站的测距偏差的标准差，
Figure PCTCN2021134998-appb-000003
σ SiS＝0.05NM，σ air＝max{0.085NM,0.00125D i}，D i指倾斜距离。
基于i,j两个DME站计算位置，得到水平位置误差：
Figure PCTCN2021134998-appb-000004
其中，α ij是航空器与两个台站之间的夹角，
Figure PCTCN2021134998-appb-000005
应服从正态分布：
Figure PCTCN2021134998-appb-000006
其中：
Figure PCTCN2021134998-appb-000007
Figure PCTCN2021134998-appb-000008
设计单一故障场景：假设航空器通过两个无故障的DME站获得初始有效位置，而随着航空器位置的变化，初始的两个站不再满足几何条件，需引入新的站DME3对初始中的一个测站进行替换，飞行管理系统(Flight Management System，FMS)将引入新的测站前的航空器位置与引入后的位置进行比较，确定潜在的测距偏差，而后计算位置解算方案的保护级。
令基于两个无故障初始站获得的测距误差R 12服从
Figure PCTCN2021134998-appb-000009
基于故障DME3的测距误差R 3服从N(μ,σ D)，故障判决形式为：
|R 12-R 3|>T→failure       (6)；
定义检验统计量R＝R 12-R 3，其中
Figure PCTCN2021134998-appb-000010
若DME3无故障，检验统计量R服从N(0,σ R)，由误检概率P fd可以求出故障检测阈值T：
Figure PCTCN2021134998-appb-000011
若DME3有故障，检验统计量R服从N(μ,σ R)，由漏检概率P md和检测阈值T求出最小可检测偏差μ m：
Figure PCTCN2021134998-appb-000012
在这里假设航空器使用DME3和DME1进行测距，通过偏差检测实现系统水平保护级(Horizontal Protection Level，HPL)的计算：
Figure PCTCN2021134998-appb-000013
将HPL与航路所要求的水平告警限进行比较，若保护级大于告警限，则系统不可用。
所述采用基于LDACS的高空用户与低空用户的空对空定位算法确定航空器的位置，具体包括：
采用Multi-DME定位算法，确定高空用户的位置信息；基于LDACS的双向测距功能，确定所述高空用户与低空用户之间的测量距离；根据所述测量距离、高空用户的位置信息，确定低空航空器的位置。详细过程如下：
(1)基于LDACS的高空用户与低空用户的空对空定位算法
由于受到地形遮挡的影响，低空用户收发导航信号的性能受限，难以实现定位。相较于此，高空用户则可以从更多地面测距源获得测距信息和测距误差信息，比如通过Multi-DME方法实现准确定位，并作为机载测距源向低空用户播发自身的位置信息和协方差矩阵，结合LDACS的空对空通信能力实现高空用户与低空用户之间的距离测量，低空用户即可实现自身位置的获取。考虑到高空测距源的数量有限，这里只进行二维定位，并利用气压高度表辅助进行高度测量。
根据高空用户测距源A的位置测量y A进行空对空测量，其位置误差ε A服从分布N(0,∑ A)。低空用户与机载测距源 n之间的距离为：
r (n)＝(x u-x (n))·1 (n)+T (n)+M (n)+c·(dt (n)-dt u)+ε (n)   (10)；其中x u和x (n)分别是航空器与测距源的位置，ε (n)为测距误差，T (n)为对流层延迟，M (n)是多径效应，dt (n)表示机载测距源的时钟偏移，dt u表示用户接收机的时钟偏 移，1 (n)为沿用户接收机和测距源连线方向的一组单位向量，在此称之为视距(Light of Sight，LoS)向量。
在RNP操作的背景下，对流层延迟T (n)和多径的影响M (n)是可以忽略不计的，因为它们通常只会引起比σ r小几个数量级的随机误差。通过LDACS的双向测距功能实现机载测距源与低空用户之间的伪距测量：
Figure PCTCN2021134998-appb-000014
其中，t t和t r分别表示低空用户发射和接收到信号的时间，τ表示高空测距源从接收信号到发射应答信号之间的已知固有延迟，c表示光速。
空对空定位算法中，机载测距源不同于卫星或者地面测距源，其位置本身存在不可忽略的不确定性，可以将其认为卫星中的星历误差，由距离测量中的噪声σ r与机载测距源沿LoS的不确定性相加得到，低空用户j处的测距误差ε (n)可近似为零均值高斯分布N(0,σ n,j)，其中：
Figure PCTCN2021134998-appb-000015
∑ n表示由测距源的位置进行定位的误差协方差矩阵，与测距源本身的位置不确定性有关，反映了由该测距源信号得到的距离测量值的精度。由于机载测距源是通过Multi-DME实现定位的，其定位精度可表示为：
Figure PCTCN2021134998-appb-000016
其中，H表示测距源与其多个DME站之间的方向余弦矩阵，那么，
Figure PCTCN2021134998-appb-000017
那么，测距误差的方差表示为：
Figure PCTCN2021134998-appb-000018
利用(10)(11)两个方程，通过加权最小化残差法进行位置解算：
δx i＝(G TWG) -1G TWδr i       (16)；
其中，G为由视距单位矢量构成的几何矩阵，与测距源相对于用户的几何位置有关，W为反映各测距源造成的测距误差的加权矩阵，其对角线元素
Figure PCTCN2021134998-appb-000019
δr i为迭代过程中得到的测距修正，当||x i+1-x i||≤ε,ε>0时，用户位置收敛于
Figure PCTCN2021134998-appb-000020
定位误差服从多元高斯分布N(0,∑)，协方差矩阵∑＝(G TWG) -1。
(2)基于最小二乘残差法的空对空协同定位完好性监测，具体包括：
通过系统的误检概率计算故障的检测阈值；根据所述检测阈值和漏检概率计算最小可检测故障；计算系统的水平精度因子；由所述最小可检测故障和所述水平精度因子计算系统的水平保护级；基于水平保护级，完成空对空定位的完好性监测，详细过程为：
空对空协同定位可以通过最小二乘残差法实现完好性监测。
线性化的伪距观测方程如下：
Y＝GX+ε          (17)；
由最小二乘法得到使得测距误差平方和最小的位置估计：
Figure PCTCN2021134998-appb-000021
测距残差矢量表示为：
Figure PCTCN2021134998-appb-000022
其中，Q ν为伪距残差矢量的协因数矩阵。在无故障条件下，残差向量的加权范数服从自由度为N-2的中心χ 2分布：
Figure PCTCN2021134998-appb-000023
空对空协同定位引入了一种新的故障模式，这可能会导致新的潜在完好性风险。类似于卫星导航中的星历故障，在空对空协同定位中，机载测距源的位 置广播可能出现故障Δx，这一故障将通过视距向量反映在测距误差中：
r (n)＝(x u-(x (n)+Δx))·1 (n)+c·(dt (n)-dt u)+ε (n)    (21)；
令Δr＝Δx·1 (n)，那么在此故障下的测距表达式为：
r (n)＝(x u-x (n))·1 (n)+Δr (n)+c·(dt (n)-dt u)+ε (n)       (22)；
当故障发生后，测距故障引起的误差Δr导致伪距残差矢量发生了变化，矢量中对应故障测距源位置的测距误差均值不再为零，这使得伪距残差矢量的范数服从非中心χ 2分布，非中心参数为Δr 2：
Figure PCTCN2021134998-appb-000024
为了评估系统的最小可检测故障，即漏检概率等于指定的完好性风险时的最大可能故障。首先通过系统的误检概率P fd计算故障的检测阈值T D：
Figure PCTCN2021134998-appb-000025
根据检测阈值和漏检概率计算最小可检测故障E r：
Figure PCTCN2021134998-appb-000026
在实际导航过程中，即使没有故障发生，仍然可能由于可见测距源的几何构型不够理想而导致完好性监测算法不可用。为了判断算法的可用性，需要计算水平保护级。由机载测距源几何构型的水平精度因子HDOP和去掉第i个测距源后的水平精度因子HDOP i得到水平精度因子的变化量δHDOP i：
Figure PCTCN2021134998-appb-000027
最后，由最小可检测故障E r和系统的HDOP(水平精度因子)计算系统的水平保护级：
HPL＝δHDOP max×σ A×E r       (27)。
所述采用组合定位算法确定航空器的位置，具体包括：
计算由m个DME站进行双向测距得到的测距误差以及由n个LDACS站单向测量得到的伪距误差；基于所述测距误差和所述伪距误差，构建测距系统的观测方程；取气压高度作为观测量，将气压升高度表引入系统中，得到高度观测方程；基于所述观测方程和所述高度观测方程，构建系统的观测模型；采用最小二乘法对所述观测模型进行求解，确定航空器的位置。
(1)组合定位算法
在GNSS不可用的情况下，基于DME/DME或LDACS的APNT算法能够为不同空域的用户提供基本的PNT功能，结合上文中的完好性监测算法为用户提供所需导航性能。
为了进一步满足部分用户对定位精度和完好性的更高需求，可以通过组合多种定位方法以提高冗余测量，例如将DME、LDACS和气压式高度表的测量相结合，基于残差最小化算法进行定位，算法框图见图3。由DME提供双向测距量，LDACS提供单向伪距测量，气压式高度表通过测量气压提供高度信息。通过对各个系统的测量信息进行组合实现更高精度的定位。
首先，计算DME和LDACS实现定位下的测距误差。
由m个DME站进行双向测距得到的测距误差为：
Figure PCTCN2021134998-appb-000028
其中，ρ i表示由第i个DME站测得的距离，s i为第i个DME站的位置，
Figure PCTCN2021134998-appb-000029
为用户位置。
由n个LDACS站单向测量得到的伪距误差为：
Figure PCTCN2021134998-appb-000030
其中，ρ Lj表示由第j个LDACS站测得的伪距，s Lj为第j个LDACS站的 位置，
Figure PCTCN2021134998-appb-000031
为用户位置，dt为时钟偏差。
将二者组合，得到测距系统的观测方程：
Figure PCTCN2021134998-appb-000032
式中，y为观测量，即测距量与近似计算距离之间的差值；G为观测矩阵，a i,j为观测矩阵的系数；x为地球坐标系下的3个位置误差(Δx、Δy、Δz)和接收机时钟偏差dt构成的待估计状态量；ε D为m×1阶矢量，ε L为n×1阶矢量，分别表示在DME和LDACS测距过程中由于传播不确定性以及接收机噪声等影响带来的测距偏差向量，其标准差分别为σ D和σ L。
为了便于将气压式高度表的观测信息引入观测方程，需要将状态量投影至地理坐标系，坐标转换公式如下：
Figure PCTCN2021134998-appb-000033
Figure PCTCN2021134998-appb-000034
Figure PCTCN2021134998-appb-000035
其中，
Figure PCTCN2021134998-appb-000036
a为基准椭球体的长半径，e为椭球扁心率。
由此迭代可以得到地理坐标系下的测距误差，将其表示为：
Figure PCTCN2021134998-appb-000037
式中，φ、λ和h分别表示纬度、经度和高度，A表示坐标转换矩阵。
取气压高度作为观测量，将气压升高度表引入系统中，得到高度观测方程：
Figure PCTCN2021134998-appb-000038
其中，H B为气压高度，
Figure PCTCN2021134998-appb-000039
为估计的用户高度，ε B表示气压式高度表的测量误差，服从零均值高斯分布，其标准差为σ B。
组合以上观测量，得到新的观测方程：
Figure PCTCN2021134998-appb-000040
式中，Z表示观测信息，包括DME、LDACS和气压式高度表的观测量；H表示观测矩阵；X表示状态量，包括地理坐标系下的三个位置误差和接收机钟差等效的测距误差；V为量测噪声矩阵，其均值为0，方差矩阵为
Figure PCTCN2021134998-appb-000041
AG为n×4阶矩阵，表示观测矩阵G经过坐标转换后得到的导航系统观测矩阵。
根据该系统模型，可通过最小二乘法求其定位解。当DME和LDACS的站点数超过3个时，方程(32)有唯一解：Δφ 1,Δλ 1,Δh 1，将其叠加到初始位置φ 0,λ 0,h 0上，得到下一近似位置，取代初始位置代入方程(32)进行迭代，直至Δφ i,Δλ i,Δh i达到所需的量级，即可得到地理坐标系下用户位置的最小二乘解。
(2)基于多解分离的APNT完好性监测，具体包括：
基于所述系统的观测模型，计算状态主估计和状态子估计；基于所述状态主估计和所述状态子估计，计算差值协方差矩阵；基于所述差值协方差矩阵，构建水平位置检验统计量；根据所述误检概率计算故障的检测阈值；根据所述 检验统计量和所述检测阈值，确定是否有故障；若是有故障，则对所述故障进行隔离，并计算系统的保护级；若是无故障，则直接计算系统的保护级；根据所述保护级，完成组合定位的完好性监测。
故障检测
在建立组合系统的观测模型基础上，采用多解分离的方法实现APNT的完好性监测。定义利用所有观测量获得的估计为主估计，排除掉一个观测量后获得的估计为子估计。设定故障阈值，通过比较不同估计之间的差值与设定阈值的大小，实现APNT故障的监测与隔离。
根据观测方程可得全观测量下得状态主估计：
X 0＝Q 0Z＝(H TWH) -1H TWZ       (35)；
其中，W＝R -1为正定加权矩阵，Q 0为完全观测条件下的最小二乘解矩阵，维数为4×(m+n+1)阶。去掉第i个距离观测量，利用剩余得观测信息进行状态求解，得到状态子估计：
Figure PCTCN2021134998-appb-000042
式中，Q' i表示排除第i个距离观测量后不完全观测条件下的4×(m+n)阶最小二乘解矩阵，为了便于后续计算，通过将第i列补零将Q' i扩充为4×(m+n+1)阶矩阵Q i，得到子估计：
X i＝Q iZ(i＝1,2,Λ,m+n)        (37)；
则主估计与子估计差值的协方差矩阵为：
Figure PCTCN2021134998-appb-000043
以此构建水平位置检验统计量
Figure PCTCN2021134998-appb-000044
根据误检概率P fd计算故障的检测阈值T i：
Figure PCTCN2021134998-appb-000045
其中，
Figure PCTCN2021134998-appb-000046
表示dP i中水平位置方向对应的最大特征值，erf -1是
Figure PCTCN2021134998-appb-000047
的反函数。
根据m+n组检验统计量和故障检测阈值进行故障判决，其依据为：
(1)无故障H 0：所有检验统计量均满足d i≤T i；
(2)有故障H 1：至少存在一组检验统计量满足d i>T i。
故障分离
在检测出故障后，需要对故障进行定位识别从而实现故障隔离。通过子估计X i及其次估计X i,j，处理过程与故障检测过程类似，需要先计算出检验统计量d i,j和检测阈值T i,j，而后进行判决，判定第n个测距源有故障的依据为：如果有且只有一个子估计X n与其所有次估计的检验统计量X n,j均小于故障检测阈值，则第n个测距源需要被隔离。
如果出现所有的子估计及其对应的所有次估计均出现大于故障检测阈值的情况，则说明出现多测距源故障，需类比此方法进一步进行分析。
多解分离法层次结构见图4。
保护级计算
在进行完好性监测后，应针对完好性要求下的可用性进行判断，计算航空器的水平保护级和垂直保护级(Vertical Protection Level，VPL)。
对应每个子估计X i的HPL i由两个部分组成：一是子估计X i与主估计X 0解分离的门限，即由误检概率P fd计算的得到的故障检测阈值T i；二是子估计自身的水平位置误差门限a i，即：
HPL i＝T i+a i        (40)；
定义子估计X i的误差协方差矩阵为：
Figure PCTCN2021134998-appb-000048
记
Figure PCTCN2021134998-appb-000049
为P i中水平位置方向对应的最大特征值，则对于给定了漏检概率P md，可得：
Figure PCTCN2021134998-appb-000050
进而计算得到多解分离法的水平保护级：
HPL＝max(HPL i)＝max(T i+a i)       (43)；
类似地，可以计算得到多解分离法的垂直保护级：
VPL＝max(VPL i)＝max(D i+a i)       (44)；
其中，
Figure PCTCN2021134998-appb-000051
Figure PCTCN2021134998-appb-000052
实施例二
如图5所示，本实施例提供的一种APNT服务的定位和完好性监测系统，包括：
需求确定模块501，用于确定目标场景下的定位精度需求。
第一定位和完好性监测模块502，用于当所述定位精度需求为高精度定位时，采用组合定位算法确定航空器的位置，并采用多解分离方式对组合定位进行完好性监测。
判断模块503，用于当所述定位精度需求为低精度定位时，判断航空器是否为高空用户。
第二定位和完好性监测模块504，用于当航空器为低空用户时，采用基于LDACS的高空用户与低空用户的空对空定位算法确定航空器的位置，并采用基于最小二乘残差法对空对空定位进行完好性监测。
第三定位和完好性监测模块505，用于当所述航空器为高空用户时，采用基于DME/DME的定位算法确定航空器的位置，并对基于DME/DME的定位算法进行完好性监测。
在所述采用基于LDACS的高空用户与低空用户的空对空定位算法确定航空器的位置方面，所述第二定位和完好性监测模块，具体包括：
高空用户位置信息单元，用于采用Multi-DME定位算法，确定高空用户的位置信息。
测量距离确定单元，用于基于LDACS的双向测距功能，确定所述高空用 户与低空用户之间的测量距离。
位置确定单元，用于根据所述测量距离、高空用户的位置信息，确定航空器的位置。
与现有技术相比，本发明的创新部分如下：
本发明提出了根据用户对定位精度的需求和实际的应用条件进行分类的方法，考虑到各种情况特性，提供了三种不同的APNT算法；
1、提出了利用LDACS的双向测距功能实现空对空相对协同定位的算法流程，给出了通过Multi-DME实现定位的机载测距源的位置误差
Figure PCTCN2021134998-appb-000053
低空用户通过LDACS实现定位的测距误差
Figure PCTCN2021134998-appb-000054
2、分析了空对空协同定位中特有的故障模式，即机载测距源自身的位置信息故障，将其类比于卫星导航中的星历故障，给出了该故障模式下的测距表达式r (n)＝(x u-x (n))·1 (n)+Δr (n)+c·(dt (n)-dt u)+ε (n)，针对该特定故障提出了利用卡方检验进行故障检验以及检测阈值的求解方法；
3、提出了适用于基于LDACS的空对空协同定位算法的水平保护级计算方法HPL＝δHDOP max×σ A×E r，用于判断APNT系统的可用性；
4、分别给出了利用DME和LDACS实现定位下的测距误差表达式，并给出了由m个DME双向测距量和n个LDACS伪距测量组合而成的测距系统的观测方程
Figure PCTCN2021134998-appb-000055
5、提出了利用DME/LDACS/气压式高度表的测量信息组合实现APNT服务的新型组合定位方法；
6、提出了将DME/LDACS组合得到的观测方程经过坐标转换到地理坐标系并与气压式高度表提供的高度观测量相结合得到组合观测方程
Figure PCTCN2021134998-appb-000056
的方法，通过最小二乘法进行定位求解；
7、根据DME/LDACS/气压式高度表组合定位系统的特性，给出了采用多解分离算法进行完好性监测的流程：根据状态方程计算状态主估计X 0＝Q 0Z＝(H TWH) -1H TWZ和状态子估计X i＝Q iZ，根据系统特性构建了新的水平位置检验统计量
Figure PCTCN2021134998-appb-000057
计算出检测阈值
Figure PCTCN2021134998-appb-000058
根据检验统计量和故障检测阈值进行系统的故障判决；
8、给出了在检测出故障后，通过计算状态子估计X i和子估计的次估计X i,j实现APNT测距源故障隔离的流程；
9、提出了根据DME/LDACS/气压式高度表组合状态方程得到的主估计与子估计差值的协方差矩阵以及系统的误检概率和漏警概率计算APNT水平和垂直保护级的方法。
从本发明提供的方案可以看出，本发明的有益效果为：
第一，本发明向航空器提供多种APNT备选方案，为GNSS不可用情况下航空器的定位难题提供解决方案；
第二、本发明依据LDACS的双向测距功能，为受到地形或建筑遮挡的低海拔用户提供了一种相对定位方法；
第三、本发明提出了利用DME/LDACS/气压式高度表进行组合定位的方法，进一步提高APNT的定位精度；
第四、本发明为实现APNT的完好性监测，提供了适用于各定位算法的故障检测算法，并通过计算保护级来证明算法的可用性；
第五、本发明有助于提高APNT在国内的重视程度，促进其算法的推广和应用。
本说明书中各个实施例采用递进的方式描述，每个实施例重点说明的都是与其他实施例的不同之处，各个实施例之间相同相似部分互相参见即可。对于实施例公开的系统而言，由于其与实施例公开的方法相对应，所以描述的比较简单，相关之处参见方法部分说明即可。
本文中应用了具体个例对本发明的原理及实施方式进行了阐述，以上实施例的说明只是用于帮助理解本发明的方法及其核心思想；同时，对于本领域的一般技术人员，依据本发明的思想，在具体实施方式及应用范围上均会有改变之处。综上所述，本说明书内容不应理解为对本发明的限制。

Claims (10)

  1. 一种APNT服务的定位和完好性监测方法，其特征在于，包括：
    确定目标场景下的定位精度需求；
    当所述定位精度需求为高精度定位时，采用组合定位算法确定航空器的位置，并采用多解分离方式对组合定位进行完好性监测；
    当所述定位精度需求为低精度定位时，判断航空器是否为高空用户；
    若否，则采用基于LDACS的高空用户与低空用户的空对空定位算法确定航空器的位置，并采用基于最小二乘残差法对空对空定位进行完好性监测。
  2. 根据权利要求1所述的一种APNT服务的定位和完好性监测方法，其特征在于，还包括：当所述航空器为高空用户时，采用基于DME/DME的定位算法确定航空器的位置，并对基于DME/DME的定位算法进行完好性监测。
  3. 根据权利要求2所述的一种APNT服务的定位和完好性监测方法，其特征在于，所述对基于DME/DME的定位算法进行完好性监测，具体包括：
    计算引入新的测站前的航空器位置与引入新的测站后的航空器位置；
    基于所述引入新的测站前的航空器位置和所述引入新的测站后的航空器位置，计算所述基于DME/DME的定位算法的保护级；
    将所述保护级与航路所要求的水平告警限进行比较，以完成基于DME/DME的定位算法的完好性监测。
  4. 根据权利要求1所述的一种APNT服务的定位和完好性监测方法，其特征在于，所述采用基于LDACS的高空用户与低空用户的空对空定位算法确定航空器的位置，具体包括：
    采用Multi-DME定位算法，确定高空用户的位置信息；
    基于LDACS的双向测距功能，确定所述高空用户与低空用户之间的测量距离；
    根据所述测量距离、高空用户的位置信息，确定低空航空器的位置。
  5. 根据权利要求1所述的一种APNT服务的定位和完好性监测方法，其特征在于，所述采用基于最小二乘残差法对空对空定位进行完好性监测，具体 包括：
    通过系统的误检概率计算故障的检测阈值；
    根据所述检测阈值和漏检概率计算最小可检测故障；
    计算系统的水平精度因子；
    由所述最小可检测故障和所述水平精度因子计算系统的水平保护级；
    基于水平保护级，完成空对空定位的完好性监测。
  6. 根据权利要求1所述的一种APNT服务的定位和完好性监测方法，其特征在于，所述采用组合定位算法确定航空器的位置，具体包括：
    计算由m个DME站进行双向测距得到的测距误差以及由n个LDACS站单向测量得到的伪距误差；
    基于所述测距误差和所述伪距误差，构建测距系统的观测方程；
    取气压高度作为观测量，将气压升高度表引入系统中，得到高度观测方程；
    基于所述观测方程和所述高度观测方程，构建系统的观测模型；
    采用最小二乘法对所述观测模型进行求解，确定航空器的位置。
  7. 根据权利要求6所述的一种APNT服务的定位和完好性监测方法，其特征在于，所述采用多解分离方式对组合定位进行完好性监测，具体包括：
    基于所述系统的观测模型，计算状态主估计和状态子估计；
    基于所述状态主估计和所述状态子估计，计算差值协方差矩阵；
    基于所述差值协方差矩阵，构建水平位置检验统计量；
    根据所述误检概率计算故障的检测阈值；
    根据所述检验统计量和所述检测阈值，确定是否有故障；
    若是有故障，则对所述故障进行隔离，并计算系统的保护级；
    若是无故障，则直接计算系统的保护级；
    根据所述保护级，完成组合定位的完好性监测。
  8. 一种APNT服务的定位和完好性监测系统，其特征在于，包括：
    需求确定模块，用于确定目标场景下的定位精度需求；
    第一定位和完好性监测模块，用于当所述定位精度需求为高精度定位时， 采用组合定位算法确定航空器的位置，并采用多解分离方式对组合定位进行完好性监测；
    判断模块，用于当所述定位精度需求为低精度定位时，判断航空器是否为高空用户；
    第二定位和完好性监测模块，用于当航空器为低空用户时，采用基于LDACS的高空用户与低空用户的空对空定位算法确定航空器的位置，并采用基于最小二乘残差法对空对空定位进行完好性监测。
  9. 根据权利要求8所述的一种APNT服务的定位和完好性监测系统，其特征在于，还包括：第三定位和完好性监测模块，用于当所述航空器为高空用户时，采用基于DME/DME的定位算法确定航空器的位置，并对基于DME/DME的定位算法进行完好性监测。
  10. 根据权利要求8所述的一种APNT服务的定位和完好性监测系统，其特征在于，在所述采用基于LDACS的高空用户与低空用户的空对空定位算法确定航空器的位置方面，所述第二定位和完好性监测模块，具体包括：
    高空用户位置信息单元，用于采用Multi-DME定位算法，确定高空用户的位置信息；
    测量距离确定单元，用于基于LDACS的双向测距功能，确定所述高空用户与低空用户之间的测量距离；
    位置确定单元，用于根据所述测量距离、高空用户的位置信息，确定低空航空器的位置。
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103592656A (zh) * 2013-10-17 2014-02-19 航天恒星科技有限公司 一种适用于星载导航接收机的自主完好性监测方法
US20140232595A1 (en) * 2011-06-30 2014-08-21 Tufts University System and method for wireless collaborative verification of global navigation satellite system measurements
CN104483678A (zh) * 2014-12-04 2015-04-01 北京航空航天大学 一种空地协同的多星座卫星导航完好性多级监测方法
CN110196434A (zh) * 2019-03-29 2019-09-03 南京航空航天大学 一种高级接收机自主完好性监测的星座动态选择方法
CN110687557A (zh) * 2019-09-24 2020-01-14 北京航空航天大学 高级接收机自主完好性监测保护级优化方法和设备
CN111007552A (zh) * 2019-11-07 2020-04-14 北京航空航天大学 基于ldacs的空地协同定位及完好性监测方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10034183B2 (en) * 2016-02-26 2018-07-24 Viasat, Inc. Dynamic signal quality criteria for satellite terminal installations
US20210356279A1 (en) * 2018-07-08 2021-11-18 Nng Software Developing And Commercial Llc. A Method and Apparatus for Optimal Navigation to Multiple Locations
US20220011426A1 (en) * 2020-07-10 2022-01-13 Skystream LLC Enhanced ldacs system that determines a-pnt information and associated methods

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140232595A1 (en) * 2011-06-30 2014-08-21 Tufts University System and method for wireless collaborative verification of global navigation satellite system measurements
CN103592656A (zh) * 2013-10-17 2014-02-19 航天恒星科技有限公司 一种适用于星载导航接收机的自主完好性监测方法
CN104483678A (zh) * 2014-12-04 2015-04-01 北京航空航天大学 一种空地协同的多星座卫星导航完好性多级监测方法
CN110196434A (zh) * 2019-03-29 2019-09-03 南京航空航天大学 一种高级接收机自主完好性监测的星座动态选择方法
CN110687557A (zh) * 2019-09-24 2020-01-14 北京航空航天大学 高级接收机自主完好性监测保护级优化方法和设备
CN111007552A (zh) * 2019-11-07 2020-04-14 北京航空航天大学 基于ldacs的空地协同定位及完好性监测方法

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