Beihang University

Kun Fang

Zhipeng Wang

Yanbo Zhu

Qiang Li

Jingtian Du

Xiaopeng Hou

Xin Li

Cheng Fang Wang

Kai Kang

Zhen Gao

Hongxia Wang

Zhiqiang Dan

Kaiyu Xue

Cong Du

Ziyi Yang

Siqi Huang

Jinqi Li

An ARAIM availability prediction method under a complex terrain environment is provided. The method includes: 1) selecting positioning points according to an air line; 2) calculating terrain shielding angles; 3) predicting visible satellites; 4) determining a fault mode that needs to be monitored; 5) calculating a positioning error variance, an influence coefficient of a nominal deviation, and a variance of a solution separation test statistic; and 6) calculating a threshold of a solution separation test, calculating a protection level, and determining availability. According to the method, the terrain shielding angles are calculated based on terrain model data, and the visible satellites are predicted based on ephemeris data or almanac data to further calculate a protection level, while determining the availability; and the accuracy of availability prediction can, by considering the effect of terrain barriers on the prediction of the visible satellites, be improved to ensure the safety of aircrafts.

ARAIM availability prediction method under complex terrain environment

The present application discloses an airborne positioning method and system for an aviation navigation network, and relates to the technical field of satellite navigation. The airborne positioning method for an aviation navigation network is applied to an omnisource navigation system, and comprises the following steps: acquiring the original observation data of the omnisource navigation system; Filtering the original observation data based on dead reckoning to obtain filtered observation data; Unify that filtered observation data in time and space to obtain observation data to be fused; The adaptive fusion algorithm of omnisource navigation based on variance optimization is adopted to fuse the observation data to be fused to obtain the fused data; the fused data is used to characterize the position of the target aircraft at the current moment. The present application can improve the accuracy of the positioning result.

Airborne positioning method in aviation navigation network based on multi-source information fusion

The present invention discloses a APNT service positioning and integrity monitoring method and system. The method includes the following steps: determining a positioning accuracy requirement in a target scene; when the positioning accuracy requirement is high-accuracy positioning, determining a position of an aircraft by adopting a combined positioning algorithm, and monitoring the integrity of a combined positioning by adopting a multi-solution separation mode; when the positioning accuracy requirement is low-accuracy positioning, judging whether the aircraft is a high-altitude user; if not, adopting an air-to-air positioning algorithm for a high-altitude user and a low-altitude user based on LDACS to determine the position of the aircraft, and adopting a least square residual method to monitor the integrity of the air-to-air positioning. According to different requirements of users on positioning accuracy and actual application conditions, the present invention can provide a variety of APNT alternative solutions for an aircraft.

APNT service positioning and integrity monitoring method and system

A constellation configuration optimization method of a low earth orbit (LEO) satellite augmentation system for an ARAIM application includes: 1, traversing vertical protection levels after all subset solutions and fault modes under the condition that integrity risk and continuity risk are equally distributed, and determining the constraint conditions of LEO satellite constellation configuration parameters; 2, determining objective functions of LEO satellite constellation configuration parameters x, x, x, x, eliminating calculated values of abnormal vertical protection levels, and screening initial populations of the parameters x, x, x, x; 3, calculating fitness of the objective functions; 4, starting from a second generation population, merging a parent population with an offspring population to form a new offspring population; 5, performing local optimal selection on the new offspring population, screening out a maximum value of the objective functions as an optimal offspring, and repeating step 4 until a genetic algebra is less than a maximum genetic algebra.

Constellation configuration optimization method of LEO satellite augmentation system for ARAIM application

A GBAS integrity risk allocation system based on key satellites is used to perform a GBAS integrity risk allocation method, including: reading data from an ephemeris at a certain time, and determining numbers of key satellites, key satellite pairs and key satellite groups at a certain time; under H2 hypothesis, allocating the integrity risks by using the fault probability of satellites in key satellite pairs or key satellite groups, where the integrity risks allocated by using the fault probability of satellites in key satellite pairs or key satellite groups include integrity risks caused by dual-receiver fault and integrity risks caused by ranging source fault; under H0 and H1 hypotheses, allocating the integrity risks by using the fault probability of non-key satellites; making an integrity allocation table according to the integrity risk allocation under the H0, H1 and H2 hypotheses.

GBAS integrity risk allocation system based on key satellites

A dynamic baseline position domain monitoring system based on satellite navigation and inertial navigation is used to perform a method, including: a) determining a coordinate system and a transformation matrix; b) calculating a theoretical coordinate value of an antenna baseline vector in a earth-centered earth-fixed coordinate system during the movement of a base station carrier; c) determining the number of antenna baseline vectors to be monitored; d) solving the measurement values of the antenna baseline vectors; e) calculating the position domain error of an antenna baseline vector change rate in three directions of x, y and z at epoch k, and normalizing the position domain errors to obtain a normalized value of the position domain errors; f) obtaining the a cumulative sum; g) comparing the cumulative sum with an error monitoring threshold value, and issuing an integrity risk alarm.

Dynamic baseline position domain monitoring system

The present invention provides a global ionospheric total electron content prediction system based on a spatio-temporal sequence hybrid framework. The prediction system implements computational processing for two types of spatio-temporal sequences, wherein for a stationary spatio-temporal sequence, a STARMA model prediction method is constructed in the present invention; for a non-stationary spatio-temporal sequence, a nonlinear spatio-temporal trend is firstly extracted from the non-stationary spatio-temporal sequence by adopting a ConvLSTM method until the extracted residual passes a stationarity test, and then the electron content is predicted using the STARMA model prediction method. By using a parallel computing method in the present invention, the computational efficiency can be greatly improved, and the operation time can be saved; meanwhile, the global ionospheric electron content distribution characteristics are fully considered, so that the ionospheric prediction algorithm itself is more in line with the space weather law and has a higher prediction accuracy.

Global ionospheric total electron content prediction system

The present invention provides a calculation method for visual navigation integrity monitoring. With the method, by use of an appropriate visual positioning model, a mathematical algorithm and rich navigation measurements, the positioning accuracy and availability of positioning results are improved, and the problem of insufficient performance of satellite integrity algorithms caused by impossible guarantee of availability of a GNSS in complex environments is solved, which is helpful to realize aircraft accurate approach and automatic landing and of great significance to ensure the safety of aviation flight.

Calculation method for visual navigation integrity monitoring

The present invention provides an integrity analysis method based on a kinematic-to-kinematic relative positioning scenario, including the following steps: a) establishing a kinematic-to-kinematic relative positioning model, and inputting navigation data; b) calculating a float solution of an integer ambiguity; c) detecting and correcting cycle slips based on a total electron content rate; d) calculating a probability of correct fix and a probability of incorrect fix for the integer ambiguity; e) determining a fault to be detected and a satellite fault probability;calculating a standard deviation &#x3b4;_(v|CF) and a position domain deviation b_m; and g) calculating an integrity risk value of a carrier phase. The present invention provides an integer ambiguity calculation algorithm for a kinematic-to-kinematic positioning system in the case of a long baseline, to calculate carrier phase integrity.

Integrity analysis method based on kinematic-to-kinematic relative positioning scenario

The present invention provides a LDACS-based air-ground cooperative positioning method. According to the method, on the basis of LDACS, users are classified into super-high-altitude users, high-altitude users, and low-altitude users, and air-ground cooperative positioning is implemented through information exchange among the users at the three levels. Meanwhile, a new fault mode and an integrity hazard are introduced into the method. Therefore, the present invention further provides a method for monitoring the integrity of a LDACS-based air-ground cooperative positioning method, including a fault detection algorithm and a protection level solving method; and proposes a method for evaluating the complexity of integrity monitoring. The LDACS-based air-ground cooperative positioning method provided in the present invention well solves the problem of the shortage of APNT services in poor terrain conditions, making the positioning results more accurate.

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Beijing, China

Kun Fang