Beihang University

Jingtian Du

Zhipeng Wang

Yanbo Zhu

Yuan Liu

Kun Fang

Xin Li

Hongxia Wang

Zhen Gao

Jisi Fang

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 invention provides a BeiDou-based grid augmentation autonomous driving multi-level warning system comprising a Beidou Satellite Ground-based Augmentation system, user terminals and a Vehicles internet system, wherein the Beidou Satellite Ground-based Augmentation system comprises Beidou grid reference stations, a data processing system and a data broadcast system; the user terminal comprises an in-vehicle receiver and a calculating chips. The present invention can reduce the occurrence of traffic accidents and reduce the loss of life and property.

Beidou-based grid augmentation autonomous driving multi-level warning system

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.

LDACS-based air-ground cooperative positioning and integrity monitoring method

The present disclosure provides a method for ARAIM fault detection based on extraction of characteristic value of pseudo-range measurement, comprising: calculating a sum of integrity risks of each of fault modes and a maximum value of the integrity risks of each of the fault modes, calculating a quantity of the fault modes by using a ratio of the sum of integrity risks of each of fault modes to an integrity risk of a largest fault, and using a sample quantity of corresponding pseudo-range measurement values as an effective sample quantity; using a ratio of a time duration T to the effective sample quantity as an effective sampling duration; sampling samples of pseudo-range measurement values that are gathered by a receiver within the effective sampling duration, to obtain an effective pseudo-range measurement set; and by using the effective pseudo-range measurement set, calculating a test statistic, and performing integrity fault detection.

Method for ARAIM fault detection based on extraction of characteristic value of pseudo-range measurement

An H-ARAIM system of optimizing a horizontal protection level includes constellations, a ground reference station and an aircraft, the ground reference station is used for receiving the satellite coordinate data of the constellations, and processing the received satellite coordinate data into an input data for the calculation of the aircraft horizontal protection level. The aircraft is built-in with a receiver and a data processor, the receiver is used for receiving the input data sent by the ground reference station, and transmitting the input data to the data processor for the data processing as follows: when a difference between a positioning solution of a full visible satellite and a positioning solution of a fault subset is within a threshold of a fault subset monitor system statistical magnitude, the receiver begins to calculate the protection level, which is calculated for protecting the iterative update.

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Beijing, China

Jingtian Du