KR100980093B1 - GNSS augmentation system - Google Patents

Abstract

The present invention provides a monitoring station for monitoring the reliability of the satellite error information transmitted from the reference station by using the satellite error information output through the transmitter of the reference station and the satellite signal received from the satellite, and a control station for controlling the reference station and the monitoring station The present invention relates to a satellite propagation reinforcement system provided with a reference station, wherein the reference station extracts and outputs a signal having a bandwidth set for a satellite signal received through a GPS antenna and a frequency of a signal output from the first broadband filter. Satellite error information is obtained from a first down converter converting a lower frequency signal, a first A / D converter converting a signal output from the first down converter into a digital signal, and a signal output from the first A / D converter. And an error information calculator for calculating and outputting the transmitter to the transmitter. Is built.

Satellite Radio Enhancement System, Upgrade, Computer, Application

Description

Satellite Radio Navigation Reinforcement System {GNSS augmentation system}

The present invention relates to a satellite radio navigation reinforcement system, and more particularly, to a satellite radio navigation reinforcement system that can be easily upgraded by a reference station or a monitoring station.

Satellite navigation systems provide location and visual information anywhere in the world, and are widely used in maritime navigation as they provide more accurate positioning services than terrestrial navigation systems such as Loran-C. . However, standalone positioning using only the current satellite propagation system alone does not satisfy the positioning accuracy required in areas with high traffic volume and high risk of collision between ships. The representative method to solve this problem is DGNSS (Differential Global Navigation Satellite Systems) positioning method using GNSS augmentation system. DGNSS positioning method uses the reference station receiver installed in the reinforcement system to extract the error component of the satellite signal, and then corrects the satellite signal error by broadcasting the extracted error component to neighboring satellite radionavigation user terminals within the range of the reference station. This is to improve the positioning accuracy.

The European Union, meanwhile, has been launched for military purposes, and the universal navigation of GPS and Russia's GLONASS (Global Navigation Satellite System) are still limited to civilian or commercial use. In order to create a new satellite navigation-related market while reducing market dependence, Galileo, a new global satellite navigation system, is under construction. In addition, the US government, which is operating GPS, has established a GPS modernization plan to meet the military and civilian needs and to gain a comparative advantage over the European Galileo satellite navigation system. GLONASS, a satellite navigation system built in Russia to cope with GPS, was incomplete operation due to the Russian economic crisis, but is currently in the process of restoring the GLONASS satellite deployment.

As mentioned above, the diversification of the satellite navigation system is further accelerating the evolution of the GPS navigation integrated GPS system (GNSS) integrated reinforcement system.

In addition, with the advent of the DGPS (Differential GPS) system, which is a satellite navigation reinforcement system for oceans not only in Korea, but also the demand for improvement of the integrated GNSS (Differential GNSS) integrated reinforcement system and related operating system is increasing. have.

The International Association of Marine aids to navigation and Lighthouse Authorities (IALA) assesses current and future use of the system and concludes that recommendations are needed to improve the retirement of obsolete systems. In order to meet the requirements of navigation system according to Maritime Organization (IMO) Resolution A.915 (22), it is expected to improve the performance of satellite navigation system through system development and technical innovation for user convenience.

Korea is also making efforts to build and enhance the integrated reinforcement system to advance DGPS, a satellite navigation reinforcement system operated by the Ministry of Land, Transport and Maritime Affairs as a national positioning infrastructure in accordance with international environmental changes.

An object of the present invention is to provide a satellite navigation reinforcement system that can be easily upgraded with respect to the improvement of the satellite navigation reinforcement system as described above.

In order to achieve the above object, the satellite navigation reinforcement system according to the present invention monitors the reliability of the satellite error information transmitted from the reference station by using the satellite error information output through the reference station transmitter and the satellite signal received from the satellite. A satellite radio wave navigation reinforcement system having a monitoring station and a control station controlling the reference station and the monitoring station, the reference station extracts and outputs a signal having a bandwidth set for a satellite signal received through a GPS antenna. A broadband filter; A first down converter for converting a frequency of the signal output from the first broadband filter into a lower frequency signal; A first A / D converter converting the signal output from the first down converter into a digital signal; And an error information calculator for calculating satellite error information from the signal output from the first A / D converter and outputting the satellite error information to the transmitter, wherein the error information calculator is constructed to be mounted on a programmable computer and executed.

Preferably, the error information calculator is for the in-phase phase correlation value, the quadrature phase correlation value, the correlation value for the leading code and the backward code to maintain synchronization with the satellite signal from the digital signal output from the first A / D converter. A first radio correlator module for providing a correlation value; A measurement value generation module for measuring initial synchronization of the satellite signal received from the correlation values provided by the first radio correlator module and a pseudo distance between a satellite and a receiver; A correction information generation module for generating the satellite error information from the measurement values measured by the measurement value generation module; And a format generation module for converting the satellite error information generated by the correction information generation module into a set transmission format and outputting the converted error format to the transmitter.

The first radio correlator module may include a serial / parallel processing unit configured to convert a serial signal output from the first A / D converter into a parallel signal; A carrier generator for generating a carrier signal; A code generator for generating a C / A code signal; A combination unit for combining and outputting the signal output from the serial / parallel processing unit, the signal output from the carrier generator, and the signal output from the code generator; And a look-up table that stores a correlation value corresponding to the combined signal output from the combiner in advance and provides a corresponding correlation value using the combined signal as an address.

More preferably, the monitoring station comprises: a second broadband filter extracting and outputting a signal having a bandwidth set for the satellite signal received through the GPS antenna; A second down converter for converting a frequency of a signal output from the second broadband filter into a lower frequency signal; A second A / D converter converting the signal output from the second down converter into a digital signal; A data link receiver for decoding and outputting a signal received through the transmitter of the reference station; And a monitoring information calculator for determining the reliability of the satellite error information from the signal output from the second A / D converter and the signal received from the link receiver, and outputting the determination result to the control station and the reference station. The monitoring information calculator is constructed to be mounted on a programmable computer and executed.

The satellite navigation reinforcement system according to the present invention can be constructed so that a part in charge of arithmetic processing of a reference station for calculating satellite error information from a received satellite signal or a monitoring station for monitoring reliability of satellite error information can be executed by a programmable computer. Therefore, it is possible to quickly cope with changes in the satellite navigation operation system and to alleviate the economic burden caused by the upgrade because the related program needs to be changed during the upgrade.

Hereinafter, the satellite radio wave reinforcement system according to the present invention will be described in more detail with reference to the accompanying drawings.

1 is a block diagram showing a satellite navigation reinforcement system according to the present invention, Figure 2 is a detailed block diagram of the reference station of FIG.

1 and 2, the satellite navigation reinforcement system includes a reference station 100, a monitoring station 200, and a control station 300.

The reference station 100 calculates satellite error information from the signal received through the GPS antenna 102 and outputs it to the transmitter 104.

The reference station 100 includes a first wideband filter 111, a first down converter 113, a first A / D converter 115, and an error information calculator 130.

The first broadband filter 111 extracts and outputs a signal having a bandwidth set for the satellite signal received through the GPS antenna 102.

The first down converter 113 mixes or subtracts a signal output from the first broadband filter 111 and a signal of a local oscillator (not shown) as a frequency mixer and converts the signal into a lower intermediate frequency (IF) signal. .

The first A / D converter 115 converts the signal output from the first down converter 113 into a digital signal.

The error information calculator 130 calculates satellite error information from the signal output from the first A / D converter 115 and outputs the satellite error information to the transmitter 104.

The error information calculator 130 is an application program that is mounted on the programmable computer 120 and executed.

The computer 120 is composed of a central processing unit 121, a ROM (ROM) 122, an input device 123, a display device 124, a storage device 125 and an input / output interface 126, and calculates error information. The device 130 is installed in the memory device 125 so as to be executed in support of the operating system.

The error information calculator 130 provides an advantage of minimizing hardware changes by easily changing a program when upgrading.

As shown in FIG. 3, the error information calculator 130 includes a first radio correlator module 131, a measurement value generating module 141, a correction information generating module 143, and an RTCM format generating module 145.

The first radio correlator module 131 removes a carrier wave and a code from the digital signal output from the first A / D converter 115 to calculate a correlation value required for synchronization with the satellite signal. The correlation value calculated by the first radio correlator module 131 is determined according to the type of discriminator for tracking the carrier and the code. For example, an in-phase correlation value and an orthogonality for the carrier tracking loop are orthogonal to each other. A quadrature-phase correlation value and a correlation value for an early code and a late code for a code tracking loop are calculated.

The first radio correlator module 131 is preferably constructed to calculate a correlation value by the processing module as shown in FIG. 5 in order to alleviate the computational burden in calculating the correlation value.

Referring to FIG. 5, the first radio correlator module 131 includes a serial / parallel processor 132, a carrier generator 133, a code generator 135, a combination unit 137, and a lookup table 138.

The serial / parallel processing unit 132 converts the serial signal output from the first A / D converter 115, that is, the number of bits set for the IF data into a parallel signal, and outputs the parallel signal to the combination unit 137.

The carrier generator 133 generates and outputs a carrier signal. Here, the carrier signal refers to an in-phase carrier signal and an orthogonal phase carrier signal generated to remove the intermediate frequency signal IF.

Preferably, the carrier generator 133 is constructed to generate a compressed carrier by generalizing the number of carrier patterns by using a characteristic that the change of neighboring carriers is small, and output the generated compressed carrier.

The code generator 135 outputs a C / A code signal. Here, the C / A code signal is a signal generated to remove the code signal received from the satellite.

Preferably, the code generator 135 is constructed to generate a compressed code signal by generalizing the number of code patterns according to the relationship between the code phase and the sampling clock, and output the generated compressed code signal.

The combiner 137 combines the signal output from the serial / parallel processing unit 132, the signal output from the carrier generator 133, and the signal output from the code generator 135, and outputs the combined signal.

As an example, the combiner 137 sequentially synthesizes a signal output from the serial / parallel processor 32, a signal output from the carrier generator 133, and a signal output from the code generator 135 in series. The columns are output as combined signals.

The look-up table (LUT) 138 stores a correlation value corresponding to the combined signal output from the combiner 137 in advance, and provides a corresponding correlation value by using the combined signal output from the combiner 137 as an address. do.

According to such a correlation processing structure, a computational burden can be reduced and a processing speed can be improved.

The first measurement value generation module 141 measures the initial synchronization of the satellite signal received from the correlation value provided by the first radio correlator module 131 and the pseudo distance between the satellite and the receiver.

The correction information generation module 143 generates satellite error information from the measured values measured by the first measurement value generation module 141. The satellite error information includes pseudorange correction information (PRC) and pseudorange rate correction information (RRC).

The RTCM format generation module 145 converts the satellite error information generated by the correction information generation module 143 into a set transmission format and outputs the converted error format to the transmitter 104.

In the illustrated example, the RTCM format generation module 145 converts the satellite error information generated by the correction information generation module 143 into a Radio Technical Commission for Maritime Services (RTCM) standard, and changes the standard when the standard is changed. It can be constructed to convert to format.

The transmitter 104 transmits satellite error information through the transmission antenna 106.

Meanwhile, the monitoring station 200 monitors the reliability of the satellite error information of the reference station 100 by using the satellite error information output through the transmitter 104 of the reference station 100 and the satellite signal received from the satellite. Output the result.

The structure of the monitoring station 200 will be described with reference to FIGS. 2 and 4.

The monitoring station 200 includes a second wideband filter 211, a second down converter 213, a second A / D converter 215, a monitoring information generator 230, and a data link receiver 250.

Here, the second wideband filter 211, the second down converter 213, and the second A / D converter 215 process the signal received through the GPS antenna 102 antenna of the reference station 100 described above. The first broadband filter 111, the first down converter 113, and the second A / D converter 115 have the same function, and detailed description thereof will be omitted.

The data link receiver 250 decodes and outputs a signal received through the transmitter 104 of the reference station 100.

The monitoring information calculator 230 determines whether the satellite error information is integrity, that is, reliability, from the signal output from the second A / D converter 215 and the signal received from the data link receiver 250, and controls the determination result. The station 300 and the reference station 100 are provided. As an example, the monitoring information calculator 230 may generate a reference station and integrity monitor (RSIM) of the RTCM SC-104 from a signal output from the second A / D converter 215 and a signal received from the data link receiver 250. The standard is constructed to determine whether the satellite error information is integrity, that is, the reliability and output the determination result.

Here, the monitoring information calculator 230 is also constructed as an application program mounted on and executed by the programmable computer 120 shown in FIG.

The monitoring information calculator 230 includes a second radio correlator module 231, a second measurement value generating module 241, and an integrity monitoring information generating module 245, as shown in FIG. 4.

The second radio correlator module 231 and the second measurement value generating module 241 perform the same functions as the first radio correlator module 131 and the first measurement value generating module 141 described above.

The integrity monitoring information generation module 245 determines whether the satellite error information generated by the reference station 100 is correct from the information received by the data link receiver 250 and the measurement value generated by the second measurement generation module 241. The determination result is provided to the reference station 100 and the control station 300 through the communication interface.

The control station 300 monitors and controls signals transmitted from the reference station 100 and the monitoring station 200.

1 is a block diagram showing a satellite navigation reinforcement system according to the present invention,

2 is a detailed block diagram of the reference station of FIG. 1;

3 is a detailed block diagram of a reference station processing module installed in the computer of FIG.

4 is a detailed block diagram of the monitoring station of FIG. 1;

FIG. 5 is a detailed block diagram of the first radio correlator module of FIG. 2.

Claims (4)

And a monitoring station for monitoring the reliability of the satellite error information transmitted from the reference station by using the satellite error information output through the transmitter of the reference station and the satellite signal received from the satellite, and a control station for controlling the reference station and the monitoring station. In the satellite radio navigation reinforcement system, The reference station A first broadband filter extracting and outputting a signal having a bandwidth set for the satellite signal received through the GPS antenna; A first down converter for converting a frequency of the signal output from the first broadband filter into a lower frequency signal; A first A / D converter converting the signal output from the first down converter into a digital signal; And an error information calculator for calculating satellite error information from the signal output from the first A / D converter and outputting the satellite error information to the transmitter. And the error information calculator is constructed to be mounted on a programmable computer to be executed. The method of claim 1, wherein the error information calculator A first radio that provides an in-phase correlation value, quadrature correlation value, correlation value for the leading code, and correlation value for the backward code to maintain synchronization with the satellite signal from the digital signal output from the first A / D converter A correlator module; A measurement generation module for measuring initial synchronization of the satellite signal received from the correlation values provided by the first radio correlator module and a pseudo distance between a satellite and a receiver; A correction information generation module for generating the satellite error information from the measurement values measured by the measurement value generation module; And a format generation module for converting the satellite error information generated by the correction information generation module into a set transmission format and outputting the converted error signal to the transmitter. The method of claim 2, wherein the first radio correlator module A serial / parallel processing unit which converts the serial signal output from the first A / D converter into a parallel signal; A carrier generator for generating a carrier signal; A code generator for generating a C / A code signal; A combination unit for combining and outputting the signal output from the serial / parallel processing unit, the signal output from the carrier generator, and the signal output from the code generator; And a look-up table that stores a correlation value corresponding to the combined signal output from the combining unit in advance and provides a corresponding correlation value using the combined signal as an address. The method of claim 3, The monitoring station A second broadband filter extracting and outputting a signal having a bandwidth set for the satellite signal received through the GPS antenna; A second down converter for converting a frequency of a signal output from the second broadband filter into a lower frequency signal; A second A / D converter converting the signal output from the second down converter into a digital signal; A data link receiver for decoding and outputting a signal received through the transmitter of the reference station; And a monitoring information calculator for determining the reliability of the satellite error information from the signal output from the second A / D converter and the signal received from the link receiver, and outputting the determination result to the control station and the reference station. and, And the surveillance information calculator is constructed to be mounted on a programmable computer to be executed.

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