CN-116243340-B - Multi-star multi-frequency precise single-point positioning precise message broadcasting method

CN116243340BCN 116243340 BCN116243340 BCN 116243340BCN-116243340-B

Abstract

The invention discloses a multi-satellite multi-frequency precise single-point positioning precise message broadcasting method which comprises the following steps of S1, characterizing satellite ephemeris by using ephemeris parameters, S2, arranging basic ephemeris and navigation auxiliary information, S3, setting different information types and navigation information corresponding to the information types according to the requirement of information updating frequency, S4, setting messages broadcast by each satellite and corresponding sequences according to the frequency points of the satellites and the number of cooperative satellites, and S5, broadcasting the messages. The method can solve the technical problems of the prior art that the quantity of satellites is large, the message data quantity is large, and the message communication efficiency is low, realize the simplification of precise message broadcasting content, improve the message broadcasting efficiency, and ensure the effect of collecting and positioning the required messages in a short time by a ground user terminal while reducing the single-satellite broadcasting data quantity.

Inventors

NIE XIN
ZHAO XIAOFANG
DONG HAIQING
MA FUJIAN
ZHAO XINGLONG
KANG CHENGBIN
WANG JINGANG
ZHENG JINJUN

Assignees

中国空间技术研究院

Dates

Publication Date: 20260512
Application Date: 20221107

Claims (6)

1. A multi-star multi-frequency precise single-point positioning precise text broadcasting method is characterized in that, The message frame length is 1000 bits, and comprises information types and navigation information, wherein the information type length is 6 bits, the navigation information length is 917 bits, the message frame length is designed according to a data block form, the data block length is fixed, the message frame length is arranged according to the information type according to the requirement of information updating frequency, and each information type corresponds to the structure of one navigation information; the broadcasting method comprises the following steps: S1, characterizing satellite ephemeris by using ephemeris parameters; S2, arranging basic ephemeris and navigation auxiliary information; s3, setting different information types and corresponding navigation information according to the requirement of information updating frequency; S4, setting the message broadcast by each satellite and the corresponding sequence according to the frequency points of the satellites and the number of the cooperative satellites; s5, broadcasting the text; The ephemeris parameters are characterized using 18 parameters, noted as , , wherein, For the reference time of the ephemeris, Is an orbit basic parameter, also called reference ephemeris, which only represents the orbit parameter of a satellite at a reference moment, and is sequentially that a semi-long axis orbits at an observation moment and the reference moment The difference, the track eccentricity, the track inclination angle and the ascending intersection point of the right ascent are measured at the observation time and the reference time The difference, the near-place amplitude angle, the reference moment average near-point angle, the track semi-long axis change rate and the track average angle correction value change rate; The long-term perturbation parameters of the track are, in sequence, the change rate of the inclination angle of the track, the change rate of the right ascent and intersection point and the average angular velocity correction of the track; The track short-term perturbation parameters are sequentially the amplitude corrected by the cosine harmonic term of the rising-point angular distance, the amplitude corrected by the sine harmonic term of the rising-point angular distance, the amplitude corrected by the cosine harmonic term of the track half shaft, the amplitude corrected by the sine harmonic term of the track half shaft, the amplitude corrected by the cosine harmonic term of the track dip angle and the amplitude corrected by the sine harmonic term of the track dip angle.
2. The method of claim 1, wherein the navigation information is first 555 bits for broadcasting basic navigation information and second 362 bits for broadcasting navigation assistance information, and wherein the navigation assistance information broadcast for different information types is different.
3. The method of claim 2, wherein the basic navigation information includes satellite PRN, text data version number, global integrity status, ephemeris parameters, clock error parameters, group delay correction parameters, and the navigation assistance information includes ionospheric delay correction model parameters, satellite yaw angle, BDT-UTC time synchronization parameters, BDT-GNSS time synchronization parameters, reduced almanac, satellite health space signal accuracy index.
4. The method according to claim 1, wherein in step S5, the broadcasting is performed by using a multi-satellite multi-frequency point coordination method, specifically, at least two satellites, namely, one satellite and the other satellites.
5. The method of claim 4 wherein the broadcasting is performed for the ephemeris, clock bias and brief almanac of the satellite to be broadcasted, wherein half of the ephemeris, clock bias and brief almanac are broadcasted at a first frequency point of the satellite one, the other satellites are broadcasted at a second frequency point of the satellite one, and the other satellites broadcast the ephemeris, clock bias and brief almanac of the satellite at the first frequency point and the second frequency point of the satellite one, but in a different sequence from the satellite one.
6. The method of claim 5, wherein the sequence of the distribution of the messages of one satellite and the other satellites is dynamically adjustable according to the number of satellites.

Description

Multi-star multi-frequency precise single-point positioning precise message broadcasting method Technical Field The invention relates to the field of low-orbit navigation satellite enhancement, in particular to a multi-satellite multi-frequency precise single-point positioning precise text broadcasting method. Background With the continuous expansion and penetration of the global navigation satellite system (Global Navigation SATELLITE SYSTEM, GNSS) in application fields such as civil use, military use and the like, people have higher requirements on the GNSS system, so that the positioning time is shortened as much as possible, the positioning precision is improved, the service quality in a severe environment is improved, the application range of the system is expanded and the backup service capability is provided by utilizing various other means as much as possible, and therefore, the demonstration and research of the navigation enhancement/backup system are necessary. With the increasing rise of various low-orbit constellations at home and abroad, the characteristics of small orbit low-altitude attenuation, quick movement, global coverage, high-power communication signal broadcasting and the like are the natural advantages of developing navigation enhancement. Navigation enhancement and backup are performed through a low-orbit satellite, and even independent providing of navigation service becomes one of the hot spots of attention in academia and industry at home and abroad. Approaches to achieving navigation performance enhancement for low-orbit navigation satellites include information enhancement and signal enhancement. The information enhancement is to improve the accuracy and reliability of navigation positioning by correcting errors of a satellite navigation positioning system. The information enhancement does not provide observables, but only provides information for eliminating GNSS system errors and improving navigation positioning performance. In order to improve the positioning accuracy of navigation service, the low-orbit satellite is required to broadcast the precise orbit and clock error of the low-orbit satellite and the medium-high-orbit satellite. Meanwhile, in order to improve the integrity of the navigation service, information such as system integrity and the like needs to be broadcasted. Because the number of satellites is large, the message data volume is large, so that the content of precise message broadcasting needs to be simplified, the efficiency of message broadcasting is improved, the data volume of single-satellite broadcasting is reduced, and meanwhile, the required message for the uniform positioning of the ground user terminal in short time content collection is ensured. Disclosure of Invention The invention aims to solve the technical problems of overcoming the defects of the prior art and providing a multi-star multi-frequency precise single-point positioning precise message broadcasting method. Therefore, the invention adopts the following technical scheme: The invention provides a multi-star multi-frequency precise single-point positioning precise message broadcasting method, wherein each frame of message is 1000 bits long and comprises an information type and navigation information, the length of the information type is 6 bits, the length of the navigation information is 917 bits, the design is carried out according to the form of a data block, the length of the data block is fixed, the arrangement is carried out according to the information type according to the requirement of information updating frequency, and each information type corresponds to the structure of one navigation information; the broadcasting method comprises the following steps: S1, characterizing satellite ephemeris by using ephemeris parameters; S2, arranging basic ephemeris and navigation auxiliary information; s3, setting different information types and corresponding navigation information according to the requirement of information updating frequency; S4, setting the message broadcast by each satellite and the corresponding sequence according to the frequency points of the satellites and the number of the cooperative satellites; s5, broadcasting the message. Further, the ephemeris parameters are characterized using 18 parameters, noted as,, wherein,For the reference time of the ephemeris,Is an orbit basic parameter, also called reference ephemeris, which only represents the orbit parameter of a satellite at a reference moment, and is sequentially that a semi-long axis orbits at an observation moment and the reference momentThe difference, the track eccentricity, the track inclination angle and the ascending intersection point of the right ascent are measured at the observation time and the reference timeThe difference, the near-place amplitude angle, the reference moment average near-point angle, the track semi-long axis change rate and the track average angle correction value change rate; The