A Navigation Enhancement Method and System Based on Low Orbit Constellation

Abstract

The present invention provides a navigation enhancement method and system based on low-orbit constellations. The method includes: (a) using low-orbit constellation satellites to broadcast navigation direct signals and navigation enhancement information; The satellite's navigation direct signal and navigation enhancement information are used for precise positioning, speed measurement and timing. With the help of the fast moving characteristics of low-orbit satellites, this method can enhance the user's observation space geometry and shorten the initialization time of the user's precise positioning. The hardware structure of the user receiver is the same as that of the general-purpose satellite navigation receiver. It only needs to receive direct signals from navigation satellites and low-orbit satellites in one direction to achieve fast and precise positioning without considering other data communication links. The navigation enhancement system includes a low-orbit constellation, a ground operation control system and user receivers. The system can achieve global coverage and provide users with high-precision, high-integrity real-time precision positioning, speed measurement and timing services.

Description

technical field [0001] The invention relates to the technical field of satellite navigation, in particular to a navigation enhancement method and system based on a low-orbit constellation. Background technique [0002] Existing global satellite navigation systems (GNSS), including Beidou, GPS, GLONASS, Galileo, etc., only provide users with navigation and positioning services better than 10 meters, which can no longer meet the needs of high-precision users. [0003] With the progress and development of core technologies such as real-time orbit and clock difference and precise point positioning technology, medium and high orbit satellite augmentation systems represented by Navcom's StarFire system and Fugro's OmniStar system have enabled the differential positioning system to reach a new level. stage. However, the above-mentioned system schemes are basically similar, and they all forward the enhanced information of the navigation system to the user terminal by renting a tran...

AI Technical Summary

Problems solved by technology

Since the convergence speed of the user's service accuracy is closely related to the geometric configuration of the navigation satellite space and the change rate of the geometric configuration, the augmented satellites of the above-mentioned systems are all in the middle and high orbits, and the angles that the satellites sweep across the zenith in a short period of time are small. The change in geometric configuration is not obvious, and the effect on accelerating the convergence of precise single-point positioning is limited. In the case of fixed ambiguity, the convergence time still needs at least 6 minutes, which cannot meet the current needs of high-precision real-time positioning.

[0004] The ground-based augmentation system and PPP+RTK technology can quickly achieve the rapid convergence of high-precision positioning, but limited by the layout of ground stations and communication links, the service coverage and availability are low, and cannot meet the needs of large-scale high-precision public applications

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