53 results about "Ground based augmentation system" patented technology

The invention discloses a GBAS integrity warning threshold estimation method based on a Gaussian expansion method. The method comprises the following steps: calculating integrity sample data accordingto integrity monitoring criteria; then, dividing parameter intervals according to the satellite elevation angle, and calculating mean value and standard deviation of the sample data in each interval;carrying out normalization on the sample data; then, drawing a distribution histogram of the normalized data; and finally, determining the optimal expansion factor through the Gaussian expansion method and generating a warning threshold value. The method meets requirements of a ground-based augmentation system for false alarm rate, and meanwhile, the integrity warning threshold determined throughthe Gaussian expansion method based on system actual data accords with the actual characteristics of the system more.

The invention discloses a wave and tide measuring method based on a Beidou ground-based augmentation system. The wave and tide measuring method based comprises the steps of: installing a GNSS receiver and a differential data communication module in a buoy body; calculating spatial position coordinates of the buoy body through GNSS satellite signals as well as navigation signal correction and auxiliary positioning signals acquired from the Beidou ground-based augmentation system; and calculating wave and tide information in the ocean according to the spatial position coordinates of the buoy body. The wave and tide measuring method based further comprises the steps of acquiring the navigation signal correction and the auxiliary positioning signals, calculating position coordinates of the buoy body, separating the wave information from the tide information, calculating wave parameters and calculating tide parameters. The wave and tide measuring method disclosed by the invention is simple and convenient, is high in wave and tide measurement accuracy, is stable and reliable, and has broad application prospect.

The present invention discloses a navigation augmentation system based on a LEO small satellite. The system comprises at least four ground stations, a LEO small satellite module, an GNSS module and a user terminal. The LEO small satellite module is arranged at the exoatmosphere and is configured to receive navigation signals including atmosphere errors sent by the ground stations over the ground and receive navigation signals without atmosphere errors of the GNSS module in the sky, the differences of the navigation signals of two are compared to obtain the atmosphere delay difference correction near the current position of the LEO small satellite module and broadcast the signals to the ground, and a user terminal receives the atmosphere delay difference correction of the LEO small satellite module so as to effectively improve the navigation location precision. The navigation augmentation system based on the LEO small satellite can improve the receiving speed and the integrity of the navigation information through the user terminal so as to solve the problems that the ground stations of a ground-based augmentation system are easy to be shielded by buildings and disturbed by multiple paths and relieve the satellite-based augmentation service scope limitation.

The invention discloses a method for generating a dual-frequency low-orbit satellite-based satellite navigation augmentation signal. For the disadvantages that the power of a transmitting signal of ahigh-orbit satellite navigation augmentation system is large, the power of a signal reaching the ground is small, a ground station is complex, the communication of a ground-based augmentation system is limited, frameworks are not unified, the concurrence pressure is large, and the maintenance cost is high, the method for generating the dual-frequency low-orbit satellite-based satellite navigationaugmentation signal is proposed. The method is mainly designed and implemented for low-orbit satellite-based satellite navigation augmentation equipment, the low-orbit satellite-based satellite navigation augmentation equipment is composed of a main control extension and a transmitting extension, the main control extension can receive a GNSS satellite navigation signal to complete orbit calculation and extrapolation, star clock taming, telegraph text framing and injection, the transmitting extension performs spread spectrum modulation on a telegraph text and a spread spectrum code, the dual-frequency satellite navigation augmentation signal is generated by designing two sets of transmitting frequencies, the cost is low, the power consumption is low, and the higher positioning precision ofthe satellite navigation augmentation signal is provided.

The embodiments of the invention provide a transmission method and device for a GBAS (Ground-Based Augmentation System) navigation message. The method comprises: ground equipment receives a global navigation satellite system (GNSS) signal; the ground equipment determines a very high frequency (VHF) data broadcast (VDB) message according to the GNSS signal; the VDB message comprises ranging sourceidentifiers and support constellation information; the ranging source identifiers comprise a ranging source identifier of the Beidou satellite and a ranging source identifier of the Galileo satellite;the ranging source identifiers are used for indicating the numbers of the satellites; the support constellation information is used for indicating the supported constellation type; and the ground equipment sends the VDB message to onboard equipment. By adopting the method, the updated VDB message can support GNSS signals of multiple stars including Beidou and multiple frequencies.

An aircraft synthetic vision display system (SVS) includes a topographical database including topographical information relating to an airport, a global positioning system receiver that receives a satellite signal from a global positioning satellite to determine a geographical position of the aircraft, and a ground-based augmentation system receiver that receives a ground-based signal from a ground-based transmitter associated with the airport, wherein the ground-based signal includes geographical information associated with the airport. The SVS further includes a computer processor that retrieves the topographical information from the topographical database based on the geographical position of the aircraft, that retrieves the geographical information associated with the airport, and that corrects the topographical information using the geographical information associated with the airport to generate corrected topographical information. Still further, the SVS includes a display device that renders three-dimensional synthetic imagery of environs of the aircraft based on the corrected topographical information.

The invention discloses a method and a system for monitoring troposphere correction parameters of a ground based augmentation system, which belong to the navigation technology field and improve precision, integrity, availability and continuity of the ground based augmentation system. The method comprises: obtaining first meteorological data and second meteorological data at present; correcting the troposphere parameters according to the first meteorological data, so as to obtain a first group of correction parameters; correcting the troposphere parameters according to the second meteorological data, so as to obtain a second first group of correction parameters; comparing the first and second groups of correction parameters with a meteorological statistical threshold, and outputting a third group of correction parameters according to the comparison result; obtaining a correction error according to augmentation data, navigation data and the third group of correction parameters, comparing the correction error with a preset correction error threshold, and giving an alarm and stopping the ground station augmentation service if the correction error is greater than the preset correction error threshold, or else carrying out the ground station augmentation service.

Systems and methods to monitor for false alarms from ionosphere gradient monitors are provided. In one embodiment, a method for mitigating false gradient alarms in a satellite navigation Ground Based Augmentation System (GBAS) ground station comprising a plurality of satellite navigation system reference receivers comprises: generating an alarm signal with an ionosphere gradient monitor (IGM) at the GBAS ground station; determining whether the alarm signal is a false alarm based on data derived from carrier phase measurements received from the plurality of satellite navigation system reference receivers; and blocking the alarm signal for at least a first duration of time based on the determining.

The invention relates to a method of real-time coordinate transformation of a ground-based augmentation system. The method comprises the following steps: sending a user name, a password, a source node and coarse position information to a NtripCaster by a user; sending the coarse position information to the ground-based augmentation system by the NtripCaster; broadcasting virtual reference station information of a coarse position to the NtripCaster by the ground-based augmentation system; decoding virtual reference station coordinates in an RTCM by the NtripCaster, and calculating velocity fields of virtual reference sites; transforming the virtual reference station ITRF coordinates into WGS84 or CGCS2000 coordinates by the NtripCaster; broadcasting the converted virtual reference station information for the user by the NtripCaster; and utilizing the converted virtual reference station information to perform relative positioning by the user, and obtaining the WGS84 and CGCS2000 coordinates. According to the method, coordinate transformation of the ground-based augmentation system is realized, the reliability and the stability of services of the ground-based augmentation system are guaranteed, an application range is wide, and the generality is high.

The invention discloses a monitoring method of a GBAS (Ground Based Augmentation System) ionospheric spatial gradient based on a pseudolite, and is mainly used in the field of GBAS ionospheric storm monitoring and relevant application. The pseudolite observed quantity is introduced into a monitoring algorithm; the problems that the ionospheric gradient monitoring results of different satellites ofthe existing BGAS ionospheric storm monitoring algorithm are mutually influenced, the complexity of a fault isolation algorithm is high, and the like are solved; the single-satellite ionospheric storm isolation monitoring is realized; and meanwhile, GBAS monitoring stations are provided. The monitoring method has the characteristics that the monitoring accuracy is high; and the realization is flexible and simple.