CN110412629B - Positioning method and positioning system based on GNSS signal simulation node - Google Patents

Abstract

Embodiments of the present invention provide a positioning method and positioning system based on GNSS signal simulation nodes. The positioning method is applied to a positioning system, and the positioning system includes: a GNSS timing receiver, a data processing server and a plurality of GNSS signal simulation nodes. The GNSS timing receiver receives the satellite signal of each navigation satellite, transmits the ephemeris to the data processing server, and transmits real-time time to the data processing server; the data processing server receives and processes the ephemeris, and transmits the processed ephemeris to the GNSS signal Simulate the node, and provide timing to the GNSS signal simulation node through the optical fiber; the GNSS signal simulation node receives the processed ephemeris, and generates and broadcasts the simulated satellite signal according to the processed ephemeris, the current epoch, and the position coordinates of the GNSS signal simulation node. , so that the device that needs positioning and navigation can receive the analog satellite signal to perform positioning according to the analog satellite signal.

Description

Positioning method and positioning system based on GNSS signal simulation node

technical field

Embodiments of the present invention relate to the technical field of GNSS positioning, and in particular, to a positioning method and a positioning system based on GNSS signal simulation nodes.

Background technique

In the outdoor environment, the vehicle navigation device can determine the specific location of the vehicle by receiving the satellite signals of the Global Navigation Satellite System (GNSS) and combining with the electronic map. In the indoor space, the vehicle navigation device cannot capture the satellite signal normally, resulting in the failure of positioning.

At present, in order to use GNSS for positioning and navigation in indoor environments, GNSS signal transponders are usually used. The GNSS signal transponder consists of an outdoor GNSS receiving antenna, a low-loss cable, an indoor GNSS transmitting antenna, and a GNSS satellite navigation signal controller. It consists of four parts. The working principle is as follows: the GNSS signal transponder will wirelessly forward the received outdoor satellite navigation signal to the room after amplification, filtering, etc., and the indoor ordinary GNSS receiver can normally receive the forwarded signal to achieve positioning.

However, due to the problem of signal attenuation when the signal is transmitted in the cable and the introduction of noise in the transmission process, the GNSS signal repeater positioning is only suitable for scenarios where only a single or a few indoor GNSS transmitting antennas are required and the cables are laid in a short distance. . When the GNSS signal transponder is used for positioning in a large-scale indoor space with serious signal occlusion, for example, in a tunnel, there is a problem that the signal is attenuated seriously and cannot be positioned.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a positioning method and a positioning system based on GNSS signal simulation nodes, which realize positioning using GNSS simulation signals without changing the GNSS receiving terminal in an environment with severe GNSS signal occlusion.

In a first aspect, an embodiment of the present invention provides a positioning method based on GNSS signal simulation nodes, which is applied to a positioning system based on GNSS signal simulation nodes. The positioning system includes: a GNSS timing receiver, a data processing server, and a plurality of GNSS signals analog node; where,

The GNSS timing receiver receives satellite signals of a plurality of navigation satellites, transmits ephemeris to the data processing server, and performs real-time time transfer to the data processing server, so that the time of the data processing server is synchronized with the satellite clock time, wherein, The navigation satellites include at least one of the following: GPS satellites and Beidou satellites;

The data processing server receives and processes the ephemeris, transmits the processed ephemeris to the GNSS signal simulation node, and performs timing on the GNSS signal simulation node through an optical fiber, so that the plurality of GNSS signals simulate Time synchronization between nodes;

The GNSS signal simulation node receives the processed ephemeris, and generates and broadcasts a simulated satellite signal according to the processed ephemeris and the current epoch, and the position coordinates of the GNSS signal simulation node. It is the time currently indicated by the satellite clock on the navigation satellite, and the simulated satellite signal is used to position the device for positioning by the satellite signal of the navigation satellite.

In some embodiments, after receiving the ephemeris, the data processing server further includes:

The ephemeris is stored in a total ephemeris, which includes the ephemeris of all navigation satellites.

In some embodiments, the data processing server saves the ephemeris, including:

The ephemeris of the navigation satellite corresponding to the ephemeris in the total ephemeris is updated according to the ephemeris.

In some embodiments, when the data processing server does not receive the ephemeris, the data processing server obtains the ephemeris of visible stars, including:

According to the ephemeris of any navigation satellite in the total ephemeris and the position coordinates of the data processing server, determine the elevation angle of the navigation satellite in the station center coordinate system with the data processing server as the origin at the current epoch ;

If the elevation angle is greater than or equal to a preset altitude cutoff angle, obtain the ephemeris of the navigation satellite.

In some embodiments, the GNSS signal simulation node generates and broadcasts simulated satellite signals according to the processed ephemeris, the epoch time of the current simulation node, and the position coordinates of the GNSS signal simulation node, including:

According to the processed ephemeris, the current epoch, and the position coordinates of the GNSS signal simulation node, determine the position coordinates of the navigation satellite and the broadcast time of the simulated satellite signal;

According to the processed ephemeris and the position coordinates of the simulated nodes, the position coordinates of the navigation satellites, and the broadcast time of the simulated satellite signals, the simulated pseudoranges and control parameters of the GNSS signal simulation nodes and the navigation satellites are calculated ;

Based on the simulated pseudoranges and the control parameters, simulated satellite signals are generated and broadcast.

In some embodiments, according to the processed ephemeris and the position coordinates of the GNSS signal simulation node, the position coordinates of the navigation satellite, and the broadcast time of the simulated satellite signal, the GNSS signal simulation node and the navigation system are calculated. Simulated pseudoranges of satellites, including:

According to the processed ephemeris, calculate the simulated pseudorange error;

Obtain the simulated true distance according to the position coordinates of the GNSS signal simulation node and the position coordinates of the navigation satellite;

The simulated pseudorange is obtained from the simulated true range and the simulated pseudorange error.

In some embodiments, generating and broadcasting simulated satellite signals according to the simulated pseudoranges and the control parameters, including:

generating an intermediate frequency digital signal according to the analog pseudorange and the control parameter;

Digital-to-analog conversion and radio frequency modulation are performed on the intermediate frequency digital signal to obtain and broadcast the analog satellite signal.

In a second aspect, an embodiment of the present invention provides a positioning system based on GNSS signal simulation nodes, including: a GNSS timing receiver, a data processing server, and a plurality of GNSS signal simulation nodes; wherein,

The GNSS timing receiver is used to receive satellite signals of multiple navigation satellites, transmit ephemeris to the data processing server, and perform real-time time transfer to the data processing server, so that the time of the data processing server is synchronized with the satellite clock time , wherein the navigation satellites include at least one of the following: GPS satellites, Beidou satellites;

The data processing server is configured to receive and process the ephemeris, transmit the processed ephemeris to the GNSS signal simulation node, and perform timing on the GNSS signal simulation node through an optical fiber, so that the plurality of Time synchronization between GNSS signal simulation nodes;

The GNSS signal simulation node is configured to receive the processed ephemeris, generate and broadcast the simulated satellite signal according to the processed ephemeris and the current epoch, and the position coordinates of the GNSS signal simulation node. The current epoch is the time currently indicated by the satellite clock on the navigation satellite, and the simulated satellite signal is used to locate the device that performs positioning through the satellite signal of the navigation satellite.

In some embodiments, after receiving the ephemeris, the data processing server is further configured to:

The ephemeris is stored in a total ephemeris, which includes the ephemeris of all navigation satellites.

In some embodiments, when the data processing server saves the ephemeris into the total ephemeris, it is specifically used for:

The ephemeris of the navigation satellite corresponding to the ephemeris in the total ephemeris is updated according to the ephemeris.

In some embodiments, when the data processing server does not receive the ephemeris, the data processing server obtains the ephemeris of visible stars, including:

According to the ephemeris of any navigation satellite in the total ephemeris and the position coordinates of the data processing server, determine the elevation angle of the navigation satellite in the station center coordinate system with the data processing server as the origin at the current epoch ;

If the elevation angle is greater than or equal to a preset altitude cutoff angle, obtain the ephemeris of the navigation satellite.

In some embodiments, when the GNSS signal simulation node generates and broadcasts the simulated satellite signal according to the processed ephemeris, the epoch time of the current simulation node, and the position coordinates of the GNSS signal simulation node, it is specifically used for :

According to the processed ephemeris, the current epoch, and the position coordinates of the GNSS signal simulation node, determine the position coordinates of the navigation satellite and the broadcast time of the simulated satellite signal;

According to the processed ephemeris and the position coordinates of the simulated nodes, the position coordinates of the navigation satellites, and the broadcast time of the simulated satellite signals, the simulated pseudoranges and control parameters of the GNSS signal simulation nodes and the navigation satellites are calculated ;

Based on the simulated pseudoranges and the control parameters, simulated satellite signals are generated and broadcast.

In some embodiments, the GNSS signal simulation node calculates the GNSS signal according to the processed ephemeris and the position coordinates of the GNSS signal simulation node, the position coordinates of the navigation satellite, and the broadcast time of the simulated satellite signal When simulating the pseudo-range between the node and the navigation satellite, it is specifically used for:

According to the processed ephemeris, calculate the simulated pseudorange error;

Obtain the simulated true distance according to the position coordinates of the GNSS signal simulation node and the position coordinates of the navigation satellite;

The simulated pseudorange is obtained from the simulated true range and the simulated pseudorange error.

In some embodiments, when the GNSS signal simulation node generates and broadcasts the simulated satellite signal according to the simulated pseudorange and the control parameter, it is specifically used for:

generating an intermediate frequency digital signal according to the analog pseudorange and the control parameter;

Digital-to-analog conversion and radio frequency modulation are performed on the intermediate frequency digital signal to obtain and broadcast the analog satellite signal.

In some embodiments, the distances between the plurality of GNSS signal simulation nodes are equal.

In a third aspect, an embodiment of the present invention provides a computer-readable storage medium, where program instructions are stored in the computer-readable storage medium, and when the program instructions are executed by a processor, any one of the first aspect of the embodiments of the present invention is implemented Methods.

In a fourth aspect, an embodiment of the present application provides a program product, the program product includes a computer program, the computer program is stored in a readable storage medium, and at least one processor in a positioning system based on a GNSS signal simulation node can be The readable storage medium reads the computer program, and the at least one processor executes the computer program to cause the electronic device to implement the method described in any one of the first aspects of the embodiments of the present application.

Embodiments of the present invention provide a positioning method and a positioning system based on GNSS signal simulation nodes. The receiver in the positioning system based on GNSS signal simulation nodes receives GPS or Beidou satellite signals, and transmits satellite signals to the data processing server. The data processing server receives and processes the ephemeris, transmits the processed ephemeris to the GNSS signal simulation node, and provides timing to each simulation node; the GNSS signal simulation node receives the processed ephemeris Calendar, according to the processed ephemeris and the current epoch, the position coordinates of the GNSS signal simulation node, generate and broadcast the simulated satellite signal, and the current epoch is the time star granted by the data processing server to the GNSS signal simulator Calendar, the analog satellite signal is used for general GPS or Beidou satellite signal receiving equipment. The positioning system based on the GNSS signal simulation node can generate and broadcast simulated satellite signals, so that the equipment that needs positioning and navigation can receive the simulated satellite signals, so that the equipment that needs positioning and navigation can receive the simulated satellite signals, so that the simulation satellite signals can be performed according to the simulated satellite signals. position. The positioning system has a simple structure, is easy to design, and has low design cost.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a signaling diagram of a positioning method based on a GNSS signal simulation node provided by an embodiment of the present invention;

2 is a signaling flow chart of a positioning method based on a GNSS signal simulation node provided by another embodiment of the present invention;

3 is a schematic structural diagram of a positioning system based on a GNSS signal simulation node provided by an embodiment of the present invention;

4 is a schematic diagram of a hardware structure of a GNSS signal simulation node provided by an embodiment of the present invention;

FIG. 5 is a schematic diagram of an application scenario provided by an embodiment of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

FIG. 1 is a signaling flowchart of a positioning method based on a GNSS signal simulation node provided by an embodiment of the present invention. The method of the embodiment of the present invention is applied to a positioning system based on a GNSS signal simulation node. The positioning system includes: a GNSS timing receiver, a data processing server, and a plurality of GNSS signal simulation nodes. As shown in FIG. 1, the method of this embodiment may include:

S101. The GNSS timing receiver receives satellite signals of multiple navigation satellites.

The navigation satellites include at least one of the following: GPS satellites and Beidou satellites.

In this embodiment, when using navigation satellites to navigate, at least 3+N navigation satellites are generally required, where N refers to the number of constellations. The embodiment of the present invention does not limit the types of navigation constellations. For example, the navigation constellations may be global positioning system (Global Positioning System, GPS) constellation, BeiDou Navigation Satellite System (BeiDou Navigation Satellite System, BDS) constellation, therefore, it is necessary to enable the receiver to receive satellite signals of Beidou satellites and GPS satellites, among which, the satellites received by the GNSS timing receiver The navigation satellite corresponding to the signal is the visible star in the current epoch, and the current epoch is the time displayed by the satellite clock on the navigation satellite. The GNSS timing receiver may be, for example, a dual-frequency GNSS receiver capable of receiving GPSL1 and BDS B1, and the receiver has a receiving antenna.

S102. The GNSS timing receiver transmits the ephemeris to the data processing server, and transmits real-time time to the data processing server, so that the time of the data processing server is synchronized with the time of the satellite clock. Correspondingly, the data processing server receives the ephemeris.

In this embodiment, the GNSS timing receiver obtains the ephemeris of the navigation satellites through the received satellite signals of the navigation satellites, and transmits the ephemeris of each navigation satellite to the data processing server. Wherein, each ephemeris includes information such as the operating orbit parameters of the corresponding navigation satellite. It should be noted that the embodiment of the present invention does not limit the transmission mode when the receiver transmits the ephemeris to the data processing server, and the transmission mode may be, for example, wired transmission, wireless transmission, or bit transmission.

In addition, the GNSS timing receiver can also perform timing on the data processing server, so that the time of the data processing server is synchronized with the time of the satellite clock on the navigation satellite.

S103. The data processing server processes the ephemeris.

In this embodiment, the data processing server performs format conversion on the received ephemeris, so that the processed ephemeris is suitable for the GNSS signal simulation node, that is, the GNSS signal simulation node can obtain the information in the processed ephemeris.

S104. The data processing server transmits the processed ephemeris to the GNSS signal simulation node, and performs timing on the GNSS signal simulation node through an optical fiber, so as to synchronize time among the multiple GNSS signal simulation nodes. Correspondingly, the GNSS signal simulation node receives the processed ephemeris.

In this embodiment, the data processing server sends the processed ephemeris to each GNSS signal simulation node, and the data processing server performs timing on each GNSS signal simulation node, so as to synchronize the time among the GNSS signal simulation nodes, and make The time of each GNSS signal simulation node is synchronized with the time of the satellite clock on the navigation satellite. The data processing server may, for example, send the processed ephemeris to each GNSS signal simulation node through an optical fiber, and perform timing on each GNSS signal simulation node. In addition, the data processing server may also send the processed ephemeris to each GNSS signal simulation node by means of wired transmission, wireless transmission, or bit transmission, for example.

It should be noted that, for example, the data processing server performs timing on each GNSS signal analog node through an optical fiber according to a certain frequency.

S105 , the GNSS signal simulation node generates and broadcasts a simulated satellite signal according to the processed ephemeris, the current epoch, and the position coordinates of the GNSS signal simulation node.

Among them, the analog satellite signal is used to position the device that is positioned by the satellite signal of the navigation satellite.

In this embodiment, multiple GNSS signal simulation nodes are set, for example, in narrow and long indoor spaces with serious signal occlusion, such as corridors and tunnels. When multiple GNSS signal simulation nodes are set, multiple GNSS signal simulation nodes can be set at equal distances. For example, for a tunnel with a long distance, multiple GNSS signal simulation nodes are set at equal distances along the tunnel in the tunnel to implement GNSS positioning in the tunnel.

For any GNSS signal simulation node, the GNSS signal simulation node generates a simulated satellite signal according to its position coordinates, the processed ephemeris, and the current epoch, wherein the position coordinates of each GNSS signal simulation node are the same as the GNSS satellites. The geocentric fixed position coordinates under the frame, for example, for GPS satellites, the position coordinates of the signal simulation nodes are in the WGS84 frame; for Beidou satellites, the position coordinates of the signal simulation nodes are in the BDCS frame.

After each GNSS signal simulation node generates an analog satellite signal, it broadcasts the analog satellite signal, so that the receiving terminal set on the device can receive the analog satellite signal to perform positioning. Wherein, the device is a device that performs positioning through satellite signals of navigation satellites. For example, a GNSS receiving terminal installed on a vehicle traveling in a tunnel receives the simulated satellite signal, and performs positioning and navigation on the vehicle according to the simulated satellite signal. Wherein, the GNSS signal simulation node broadcasts the simulated satellite signal through a broadcast antenna set on the GNSS signal simulation node.

In this embodiment, the receiver in the positioning system based on the GNSS signal simulation node receives GPS or Beidou satellite signals, and transmits ephemeris to the data processing server according to each satellite signal; the data processing server receives and processes The ephemeris transmits the processed ephemeris to the GNSS signal simulation node; the GNSS signal simulation node receives the processed ephemeris, and according to the processed ephemeris and the current epoch, the The position coordinates of the GNSS signal simulation node, generate and broadcast the simulated satellite signal, the current epoch is the time given by the ephemeris data processing server to each GNSS signal simulation node, and the simulated satellite signal is used for GNSS reception in the application scenario equipment. The positioning system based on the GNSS signal simulation node can generate and broadcast simulated satellite signals, so that the equipment that needs positioning and navigation can receive the simulated satellite signals to perform positioning according to the simulated satellite signals. Moreover, the positioning system is simple in structure, easy to design, and low in design cost.

In some embodiments, after S102, the positioning method further includes:

S106. The data processing server saves the ephemeris into a total ephemeris, where the total ephemeris includes the ephemeris of all navigation satellites.

In this embodiment, when receiving the ephemeris of any navigation satellite in the current epoch, the data processing server saves the ephemeris in the ephemeris of the navigation satellite corresponding to the ephemeris in the total ephemeris, wherein the total ephemeris The ephemeris of all navigation satellites is included in the calendar. Therefore, when the data processing server cannot receive the ephemeris transmitted by the GNSS timing receiver, according to the saved ephemeris of the navigation satellite, the GNSS signal simulation node generates and broadcasts the simulated satellite signal.

In some embodiments, a possible implementation manner of S106 is: updating the ephemeris of the navigation satellite corresponding to the ephemeris in the total ephemeris according to the ephemeris.

In this embodiment, when the data processing server receives the ephemeris, the ephemeris to the navigation satellite corresponding to the ephemeris that has been saved in the data processing server is updated through the ephemeris. That is, if the ephemeris of one of the navigation satellites received in the current epoch is different from the ephemeris of the navigation satellite in the total ephemeris, the ephemeris of the navigation satellite in the total ephemeris of all the navigation satellites is updated is the received ephemeris of the navigation satellite.

In this embodiment, the total ephemeris can be updated in the data processing server, so that the ephemeris of each navigation satellite in the total ephemeris is the latest ephemeris, which improves the timeliness of the total ephemeris. When the GNSS timing receiver cannot receive the satellite signal of the navigation satellite or the data processing server cannot receive the ephemeris transmitted by the GNSS timing receiver, the simulated satellite signal generated and broadcasted according to the total ephemeris is closer to the real satellite signal, so that the simulated satellite signal generated and broadcasted according to the total ephemeris is closer to the real satellite signal. The positioning is more accurate when positioning satellite signals.

In some embodiments, when the GNSS timing receiver cannot receive the satellite signal of the navigation satellite or the data processing server cannot receive the ephemeris transmitted by the GNSS timing receiver, a possible implementation of S103 is:

S1031. According to the ephemeris of any navigation satellite in the total ephemeris and the position coordinates of the data processing server, determine that the navigation satellite is in the station center coordinate system with the data processing server as the origin at the current epoch the elevation angle.

In this embodiment, for any navigation satellite, the ephemeris of the navigation satellite in the current epoch can be calculated according to the ephemeris of the navigation satellite stored in the data processing server, wherein the calculated ephemeris is close to the navigation satellite The true ephemeris at the current epoch. According to the calculated ephemeris and the position coordinates of the data processing server, the elevation angle of the navigation satellite in the station center coordinate system with the data processing server as the origin is determined.

S1032. If the elevation angle is greater than or equal to a preset altitude cutoff angle, obtain the ephemeris of the navigation satellite.

In this embodiment, for any navigation satellite, if the elevation angle of the navigation satellite is greater than or equal to the preset altitude cut-off angle, it means that the navigation satellite is a visible star in the current epoch. Ephemeris at the current epoch.

After obtaining the ephemeris of all visible stars at the current epoch, the data processing server converts the format of the ephemeris, so that the GNSS signal simulation node can recognize the converted ephemeris.

In this embodiment, the data processing server can calculate the position of each navigation satellite in the current epoch according to the stored ephemeris of the navigation satellite, and judge the visible stars according to the calculated position of the navigation satellite in the current epoch, so that the calculated The ephemerides of the visible stars at the current epoch are sent to the GNSS signal simulation node, so that the GNSS signal simulation node can generate simulated satellite signals, so that the positioning equipment can be positioned through the satellite signals of the navigation satellites.

FIG. 2 is a signaling flowchart of a method for locating a node based on a GNSS signal simulation provided by another embodiment of the present invention. On the basis of the foregoing embodiments, the method of this embodiment includes:

S201. The GNSS timing receiver receives satellite signals of multiple navigation satellites.

S202. The GNSS timing receiver transmits the ephemeris to the data processing server, and performs real-time time transfer to the data processing server, so that the time of the data processing server is synchronized with the time of the satellite clock. Correspondingly, the data processing server receives the ephemeris.

S203, the data processing server processes the ephemeris.

S204: The data processing server transmits the processed ephemeris to the GNSS signal simulation node, and performs timing on the GNSS signal simulation node through an optical fiber, so as to synchronize time among the multiple GNSS signal simulation nodes. Correspondingly, the GNSS signal simulation node receives the processed ephemeris.

In this embodiment, for the description of S201-S204, reference may be made to S101-S104, and details are not repeated here.

S205. The GNSS signal simulation node determines the position coordinates of the navigation satellite and the broadcast time of the simulated satellite signal according to the processed ephemeris, the current epoch, and the position coordinates of the GNSS signal simulation node.

In this embodiment, for any visible navigation satellite, the data processing server transmits the ephemeris of the navigation satellite to each GNSS signal simulation node. Since the processed ephemeris includes information such as the operating orbit parameters of the navigation satellites, the processed ephemeris is received according to the information such as the operating orbit parameters of the navigation satellites included in the processed ephemeris and each GNSS signal simulation node receives the processed ephemeris. The time of the GNSS signal simulation node and the position coordinates of the GNSS signal simulation node can determine the position of the navigation satellite, for example, the position coordinates of the navigation satellite in the Earth-Centered, Earth-Fixed, ECEF can be determined.

For any GNSS signal simulation node, after the position coordinates of the navigation satellite are determined, the GNSS signal simulation node is determined according to the position coordinates of the GNSS signal simulation node, the current epoch of the GNSS signal simulation node and the position coordinates of the navigation satellite to broadcast the simulation. The moment of the satellite signal.

S206, according to the processed ephemeris and the position coordinates of the GNSS signal simulation node, the position coordinates of the navigation satellite, and the broadcast time of the simulated satellite signal, calculate the simulated pseudo-simulation between the GNSS signal simulation node and the navigation satellite distance and control parameters.

In this embodiment, for any GNSS signal simulation node, after the position coordinates of the navigation satellite are determined, the GNSS signal simulation node is calculated according to the processed ephemeris, the position coordinates of the GNSS signal simulation node, and the position coordinates of the navigation satellite. Simulated pseudorange and control parameters with navigation satellites. Wherein, the control parameters may include, for example, signal amplitude, carrier frequency, carrier phase, code rate, and code phase, and the code rate and code phase are calculated according to the transmission time of the simulated satellite signal; the position of the node is simulated according to the position coordinates of the navigation satellite and the GNSS signal. Coordinates, calculate the Doppler frequency shift parameters of the relative motion between the navigation satellite and the GNSS signal simulation node, and then calculate the carrier frequency and carrier phase. The signal amplitude is used to indicate the strength of the generated analog satellite signal. Since the strength of the satellite signal of the navigation satellite is weak, it is necessary to set the strength of the analog satellite signal through the signal amplitude, so that the strength of the analog satellite signal is close to that of the satellite signal of the navigation satellite. strength so that the receiving terminal can identify the analog satellite signal. The signal amplitude is set according to actual needs, which is not limited in this embodiment of the present invention.

S207. Generate and broadcast an analog satellite signal according to the simulated pseudorange and the control parameter.

In this embodiment, for any GNSS signal simulation node, the simulated satellite signal is generated and broadcasted according to the simulated pseudorange and the control parameter.

In this embodiment, after receiving the processed ephemeris, the GNSS signal simulation node in the positioning system determines the The position coordinates of the navigation satellite and the broadcast time of the simulated satellite signal; according to the processed ephemeris and the position coordinates of the simulated node, the position coordinates of the navigation satellite, and the broadcast time of the simulated satellite signal, the GNSS signal simulation is calculated. simulated pseudo-ranges and control parameters between the node and the navigation satellite; generate and broadcast simulated satellite signals according to the simulated pseudo-ranges and the control parameters. The positioning system based on the GNSS signal simulation node can generate the simulated satellite signal, and broadcast the simulated satellite signal at the broadcast time of the simulated satellite signal, so that the equipment that needs positioning and navigation can receive the simulated satellite signal to perform positioning according to the simulated satellite signal.

In some embodiments, a possible implementation manner of calculating the simulated pseudorange in S206 is:

S2061. Calculate the simulated pseudorange error according to the processed ephemeris.

In this embodiment, since the navigation terminal installed on the device that needs to be positioned, for example, the vehicle-mounted navigation terminal, after receiving the satellite signal of the navigation satellite, when performing the positioning calculation, it will automatically correct the calculated pseudorange observation value. Therefore, in the embodiment of the present invention, pseudorange error needs to be considered when calculating the simulated pseudorange, so that when the navigation terminal performs positioning calculation according to the simulated satellite signal, the calculated positioning result is more accurate.

The pseudorange error can be calculated and obtained according to the processed ephemeris, and the pseudorange error includes error delays such as satellite clock error, ionospheric delay, and tropospheric delay. Wherein, the method for calculating the pseudo-range error can be, for example, calculating the pseudo-range error according to the error model disclosed in the ICD files of GPS and BDS, the satellite clock error is calculated and obtained by, for example, a polynomial model, and the ionospheric delay is calculated and obtained by, for example, a Klobuchar 8 parameter model, The tropospheric delay is calculated, for example, using the Hopfield model.

S2062. Obtain a simulated true distance according to the position coordinates of the GNSS signal simulation node and the position coordinates of the navigation satellite.

In this embodiment, for any visible star, the data processing server transmits the processed ephemeris corresponding to the visible star to each GNSS signal simulation node. After the GNSS signal simulation node receives the processed ephemeris, since the time of the visible star is synchronized with the time of the GNSS signal simulation node, and the processed ephemeris also includes the time when the visible star broadcasts the satellite signal. . Therefore, each GNSS signal simulation node can calculate the time between the broadcast of the satellite signal from the visible satellite and the receipt of the processed ephemeris by each GNSS signal simulation node according to the current epoch and the time when the visible satellite broadcasts the satellite signal. , and then calculate the simulated true distance between each GNSS signal simulation node and the visible star according to the transmission rate of the satellite signal and ephemeris. The simulated true distance is the true distance between each GNSS signal simulated node and the visible star obtained by calculation.

S2063. Obtain the simulated pseudorange according to the simulated true distance and the simulated pseudorange error.

In this embodiment, the simulated pseudorange is obtained according to the simulated true distance and the pseudorange error. Since the simulated pseudorange includes a pseudorange error, the navigation terminal performs positioning calculation according to the simulated satellite signal generated by the simulated pseudorange. , the calculated distance between each GNSS signal simulation node and the visible star is closer to the real distance between each GNSS signal simulation node and the visible star, so that the positioning is more accurate.

In this embodiment, when the simulated pseudorange is calculated, the pseudorange error is calculated according to the processed ephemeris, and the simulated true distance is obtained according to the position coordinates of the simulated node and the position coordinates of the navigation satellite according to the GNSS signal. True range obtains simulated pseudorange. Considering the pseudorange error in the simulated pseudorange, the distance between each GNSS signal simulation node and the visible star calculated by the navigation terminal can be closer to the real distance between each GNSS signal simulation node and the visible star, so that the more accurate positioning.

In some embodiments, a possible implementation of S207 is:

S2071. Generate an intermediate frequency digital signal according to the analog pseudorange and the control parameter.

S2072. Perform digital-to-analog conversion and radio frequency modulation on the intermediate frequency digital signal to obtain and broadcast the analog satellite signal.

In this embodiment, pseudocode modulation and carrier modulation are performed according to the analog pseudorange to generate an intermediate frequency digital signal, and then digital-to-analog conversion is performed on the analog intermediate frequency digital signal to convert the intermediate frequency digital signal into an intermediate frequency analog signal. After frequency conversion, the radio frequency signal is obtained, that is, the analog satellite signal, and the GNSS signal analog node broadcasts the analog satellite signal.

In this embodiment, after the GNSS signal simulation node obtains the processed ephemeris, the position coordinates of the navigation satellite are determined according to the processed ephemeris and the current epoch, and the position coordinates of the GNSS signal simulation node; The processed ephemeris and the position coordinates of the GNSS signal simulation node and the position coordinates of the navigation satellite are calculated, and the simulated pseudorange of the GNSS signal simulation node and the navigation satellite is calculated; according to the processed ephemeris , the current epoch, and the simulated pseudorange to generate and broadcast simulated satellite signals. The GNSS signal simulation node generates and broadcasts the simulated satellite signal according to the processed ephemeris corresponding to the visible star, the current epoch, and the position coordinates of the GNSS signal simulation node, so that the simulated satellite signal is closer to the satellite signal broadcast by the navigation satellite, thereby improving the positioning accuracy.

FIG. 3 is a schematic structural diagram of a positioning system based on GNSS signal simulation nodes provided by an embodiment of the present invention. As shown in FIG. 3 , the positioning system of this embodiment includes: a GNSS timing receiver 31 , a data processing server 32 and a plurality of GNSS Signal simulation node 33 . in,

The GNSS timing receiver 31 is used to receive satellite signals of a plurality of navigation satellites, transmit ephemeris to the data processing server 32, and perform real-time time transfer to the data processing server 32, so that the time of the data processing server 32 is the same as that of the data processing server 32. Time synchronization of satellite clocks, wherein the navigation satellites include at least one of the following: GPS satellites, Beidou satellites;

The data processing server 32 is configured to receive and process the ephemeris, transmit the processed ephemeris to the GNSS signal simulation node 33, and perform timing on the GNSS signal simulation node 33 through an optical fiber, so that all Time synchronization between the multiple GNSS signal simulation nodes 33;

The GNSS signal simulation node 33 is configured to receive the processed ephemeris, generate and broadcast simulated satellite signals according to the processed ephemeris and the current epoch, and the position coordinates of the GNSS signal simulation node 33, The current epoch is the time currently indicated by the satellite clock on the navigation satellite, and the analog satellite signal is used to position the device for positioning by the satellite signal of the navigation satellite.

In some embodiments, after receiving the ephemeris, the data processing server 32 is further configured to:

The ephemeris is stored in a total ephemeris, which includes the ephemeris of all navigation satellites.

In some embodiments, when the data processing server 32 saves the ephemeris into the total ephemeris, it is specifically used for:

The data processing server 32 updates the ephemeris of the navigation satellite corresponding to the ephemeris in the total ephemeris according to the ephemeris.

In some embodiments, when the GNSS signal simulation node 33 generates and broadcasts the simulated satellite signal according to the processed ephemeris, the epoch time of the current simulation node, and the position coordinates of the GNSS signal simulation node 33, the specific Used for:

According to the processed ephemeris, the current epoch, and the position coordinates of the GNSS signal simulation node 33, determine the position coordinates of the navigation satellite and the broadcast time of the simulated satellite signal;

According to the processed ephemeris, the position coordinates of the simulated nodes, the position coordinates of the navigation satellites, and the broadcast time of the simulated satellite signals, the simulated pseudo-ranges between the GNSS signal simulation nodes 33 and the navigation satellites and the control parameter;

Based on the simulated pseudoranges and the control parameters, simulated satellite signals are generated and broadcast.

In some embodiments, when the data processing server does not receive the ephemeris, the data processing server 32 processes the ephemeris, specifically for:

According to the ephemeris of any navigation satellite in the total ephemeris and the position coordinates of the data processing server 32, it is determined that the navigation satellite is in the station center coordinate system with the data processing server 32 as the origin at the current epoch the elevation angle;

If the elevation angle is greater than or equal to a preset altitude cutoff angle, obtain the ephemeris of the navigation satellite.

In some embodiments, the GNSS signal simulation node 33 calculates the When the GNSS signal simulates the pseudo-range between the node 33 and the navigation satellite, it is specifically used for:

According to the processed ephemeris, calculate the simulated pseudorange error;

Obtain the simulated true distance according to the position coordinates of the GNSS signal simulation node 33 and the position coordinates of the navigation satellites;

The simulated pseudorange is obtained from the simulated true range and the simulated pseudorange error.

In some embodiments, when the GNSS signal simulation node 33 generates and broadcasts the simulated satellite signal according to the simulated pseudorange and the control parameter, it is specifically used for:

generating an intermediate frequency digital signal according to the analog pseudorange and the control parameter;

Digital-to-analog conversion and radio frequency modulation are performed on the intermediate frequency digital signal to obtain and broadcast the analog satellite signal.

The positioning apparatus in this embodiment can be used to implement the technical solutions of the above method embodiments, and the implementation principles and technical effects thereof are similar, and details are not described herein again.

In some embodiments, as shown in FIG. 3 , the distances between the plurality of GNSS signal simulation nodes 33 are equal.

In this embodiment, when setting the distance between adjacent GNSS signal simulation nodes, it is necessary to consider the positioning accuracy index and the interference between simulated satellite signals broadcast by multiple GNSS signal simulation nodes. For example, in a tunnel, due to the multipath effect in the tunnel Seriously, the multipath effect error of the vehicle navigation terminal to the signal interference between each node is relatively large. Therefore, it is necessary to maintain a certain distance between adjacent GNSS signal simulation nodes. In addition, since the positioning accuracy index is generally at the meter level, the layout distance of GNSS signal simulation nodes is generally about 10 meters to 50 meters. Generally, in the tunnel, the reasonable layout distance is generally about 30 meters.

FIG. 4 is a schematic diagram of a hardware structure of a GNSS signal simulation node provided by an embodiment of the present invention. As shown in FIG. 4 , the hardware of the GNSS signal simulation node includes: a digital signal simulation module 41 , a digital-to-analog conversion module 42 , a radio frequency (Radio Frequency, RF) conversion module 43 and an antenna module 44 . in,

The digital signal simulation module 41 is used to generate an intermediate frequency digital signal according to the analog pseudorange, wherein the digital signal simulation module 41 can be based on, for example, a digital signal simulation module of an ARM development board. The digital-to-analog conversion module 42 is used for converting an intermediate frequency digital signal into an intermediate frequency analog signal. The RF conversion module 43 is used to up-convert the intermediate frequency analog signal to a radio frequency signal, that is, an analog satellite signal. The antenna module 44 is used for broadcasting frequency signals.

In some embodiments, continuing as shown in FIG. 4 , the hardware of the GNSS signal simulation node may further include: a transmission rate control module 45 . In some embodiments, continuing as shown in FIG. 4 , the hardware of the GNSS signal simulation node may further include: a temperature compensated crystal oscillator module 46 .

The transmission rate control module 45 is used to control the amount of the intermediate frequency digital signal generated by the digital signal simulation module 41 and the sampling rate of the digital-to-analog conversion module 42 . The transmission rate control module 45 may be, for example, an FPGA-based transmission rate control module. The temperature-compensated crystal oscillator module 46 acts as an external clock to precisely control the synchronous transmission of the data volume of the intermediate frequency digital signal generated by the digital signal analog module 41 and the data volume of the intermediate frequency digital signal converted by the digital-to-analog conversion module 42, and can also solve the problem of temperature drift and temperature drift. Stability issues. The transmission rate control module 45 and the temperature compensated crystal oscillator module 46 realize the matching of the intermediate frequency digital signal generation rate and the intermediate frequency analog signal sampling rate, so that the generated analog satellite signal is closer to the satellite signal broadcast by the navigation satellite, thereby improving the positioning accuracy.

FIG. 5 is a schematic diagram of an application scenario provided by an embodiment of the present invention. This embodiment is described by taking the application of a positioning system based on GNSS signal simulation nodes in a tunnel as an example. As shown in FIG. 5 , multiple GNSS signal simulation nodes are arranged at equal distances along the tunnel, and each GNSS signal simulation node generates and broadcasts simulation Satellite signal, the vehicle driving in the tunnel receives the GNSS signal closest to it in real time. The analog node generates and broadcasts the analog satellite signal, and performs positioning according to the received analog satellite signal.

Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by program instructions related to hardware. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps including the above method embodiments are executed; and the foregoing storage medium includes: a read-only memory (Read-Only Memory, ROM), a random access memory (random access memory, RAM), a magnetic disk or Various media that can store program codes, such as optical discs.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims (10)

1. A positioning method based on a GNSS signal simulation node is applied to a positioning system for positioning the GNSS signal simulation node based on a global navigation satellite system, and the positioning system comprises: the GNSS time service system comprises a GNSS time service receiver, a data processing server and a plurality of GNSS signal simulation nodes; wherein,

the GNSS time service receiver receives satellite signals of a plurality of navigation satellites, transmits ephemeris to the data processing server, and transmits real-time to the data processing server so as to synchronize the time of the data processing server with the time of a satellite clock, wherein the navigation satellites comprise at least one of the following: GPS satellites, Beidou satellites;

the data processing server receives and processes the ephemeris, transmits the processed ephemeris to the GNSS signal simulation nodes, and carries out time service on the GNSS signal simulation nodes through optical fibers so as to synchronize time among the plurality of GNSS signal simulation nodes;

and the GNSS signal simulation node receives the processed ephemeris, generates and broadcasts a simulation satellite signal according to the processed ephemeris, a current epoch and the position coordinates of the GNSS signal simulation node, wherein the current epoch is the current indicated time of a satellite clock on the navigation satellite, and the simulation satellite signal is used for positioning equipment for positioning through the satellite signal of the navigation satellite.

2. The method of claim 1, wherein after the data processing server receives the ephemeris, further comprising:

and storing the ephemeris into a general ephemeris, wherein the general ephemeris comprises the ephemeris of all navigation satellites.

3. The method of claim 2, wherein the data processing server saving the ephemeris into a general ephemeris comprises:

and updating the ephemeris of the navigation satellite corresponding to the ephemeris in the general ephemeris according to the ephemeris.

4. The method of claim 3, wherein if the data processing server does not receive the ephemeris, the method comprises:

determining an elevation angle of the navigation satellite in a station center coordinate system with the data processing server as an origin when the navigation satellite is in the current epoch according to the ephemeris of any one of the navigation satellites in the total ephemeris and the position coordinate of the data processing server;

and if the elevation angle is larger than or equal to a preset altitude cut-off angle, acquiring ephemeris of the navigation satellite.

5. The method of claim 1 or 4, wherein the generating and broadcasting by the GNSS signal simulation node simulated satellite signals according to the processed ephemeris and the epoch time of the current simulation node and the position coordinates of the GNSS signal simulation node comprises:

determining the position coordinates of the navigation satellite and the broadcasting time of the simulated satellite signals according to the processed ephemeris, the current epoch and the position coordinates of the GNSS signal simulation node;

calculating a simulated pseudo range and a control parameter of the GNSS signal simulation node and the navigation satellite according to the processed ephemeris, the position coordinate of the simulation node, the position coordinate of the navigation satellite and the signal broadcasting time of the simulated satellite;

and generating and broadcasting a simulated satellite signal according to the simulated pseudo range and the control parameter.

6. The method of claim 5, wherein calculating the simulated pseudoranges of the GNSS signal simulating node and the navigation satellites according to the processed ephemeris and the position coordinates of the GNSS signal simulating node, the position coordinates of the navigation satellites and the simulated satellite signal broadcast time comprises:

calculating a simulated pseudo-range error according to the processed ephemeris;

acquiring a simulation true distance according to the position coordinate of the GNSS signal simulation node and the position coordinate of the navigation satellite;

and obtaining the simulated pseudorange according to the simulated true range and the simulated pseudorange error.

7. The method of claim 5, wherein generating and broadcasting analog satellite signals based on the analog pseudoranges and the control parameters comprises:

generating an intermediate frequency digital signal according to the analog pseudo range and the control parameter;

and D/A conversion and radio frequency modulation are carried out on the intermediate frequency digital signal, and the analog satellite signal is obtained and broadcast.

8. A positioning system based on GNSS signal simulation nodes, comprising: a GNSS time service receiver, a data processing server and a plurality of GNSS signal simulation nodes for performing the method of any of the preceding claims 1 to 7.

9. The position determination system of claim 8, wherein the plurality of GNSS signal simulation nodes are equidistant from each other.

10. A readable storage medium, characterized in that the readable storage medium has stored thereon a computer program; the computer program, when executed, implements a method for GNSS signal simulation node based positioning according to any of claims 1-7.

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