KR102166976B1 - Unlimited network-realtime kinematic method and virtual reference station using thereof - Google Patents

Abstract

A real-time positioning method according to an embodiment of the present invention includes the steps of dividing an area into a plurality of areas; Setting one virtual reference station for each of the plurality of regions, and estimating phase information at the positions of each virtual reference station; Determining in which of the plurality of areas the first mobile station is located based on location information from the first mobile station; And transmitting, to the first mobile station, phase information of a virtual reference station set in an area where the first mobile station is located.

Description

Unlimited network-RTK method and virtual reference station server using it {UNLIMITED NETWORK-REALTIME KINEMATIC METHOD AND VIRTUAL REFERENCE STATION USING THEREOF}

The present invention relates to an unlimited network-RTK method and a virtual reference station server using a GNSS (Global Navigation Satellite System) satellite, and in particular, a network-RTK method capable of supporting a plurality of users by using one virtual reference station in a certain area, and It relates to a virtual reference station server.

GNSS is a collective term for a location-finding system or its device using an artificial satellite, and is a system developed to inform one's exact current location at any point on the earth. Russia's GLONASS (GLObal NAvibation Satellite System), including GPS (Global Positioning System), developed for the purpose of providing accurate current position information to aircraft and vessels in flight by supplementing the naval navigation satellite system used by the US Department of Defense for military purposes. And European Galileo et al. correspond to this GNSS.

Due to the advantage that the GNSS can know relatively accurate location information with only a simple receiver, the range of use of GNSS is expanding not only to navigation systems such as aircraft and ships, but also to construction equipment, personal laptop computers, and mobile phones.

However, in the above GNSS, after the signal is transmitted from the transmitter of the GNSS satellite, it is received by the receiver to obtain a position result. Various factors (satellite clock error, satellite orbit error, ionospheric delay error, convective layer error, Multipath errors, etc.) exist, and the user may obtain inaccurate location results due to these error factors. Accordingly, various methods for obtaining more accurate location information have been developed, and among them, the Real-Time Kinematic (RTK) method, which is a relative positioning method using phase information, is emerging as the most widely used method.

The RTK method determines the position based on the double difference between the phase information of the carrier wave observed by the reference station and the mobile station. The double difference method enables accurate positioning by eliminating the common error including the amount of time deviation of the satellites and receivers, and is a method of linearly combining (differentiating) four observation data with two receivers and two satellites. The double difference is a method of re-differentiating the two single differences, and it is possible to eliminate the amount of visual deviation and orbital error of the satellite through the single difference. However, due to the single difference, the ambiguity constant becomes real, and there is a disadvantage in that errors related to the receiver cannot be eliminated. Accordingly, this is a method of removing the amount of visual bias of the receiver and the phase error of the internal carrier of the receiver by differentiating them again, and making the real number of ambiguous constants integer so that the constraint that the ambiguous constant is an integer can be used.

The carrier phase double difference equation is related to the distance between the receiver and the satellite, the ionosphere error and convective layer delay error, ambiguous constant, multipath and observation error, and can be expressed as the following equation.

When the two receivers form a short baseline, since the correlation between the common error increases, the parameter related to the common error can be canceled in the above equation. This is called SRTK, and it is generally known that positioning accuracy of several centimeters can be secured within 10 to 20 kilometers of the baseline distance. However, in order to expand the service nationwide, there is a disadvantage that the deployment of the reference station must be very dense.

Therefore, in order to compensate for the shortcomings of SRTK, an RTK method of estimating and erasing a common error at the location of a mobile station using a plurality of reference stations was developed (NRTK), and it is known that stable positioning is generally possible within tens of kilometers. have.

There is a Virtual Reference Station (VRS) method as a method of estimating and correcting an error that varies depending on a distance between a reference station and an arbitrary point in a network using a plurality of reference stations. The VRS method generates virtual carrier phase observation information (phase information) including an error correction value depending on the distance to the corresponding location using the approximate location information of the mobile station, and transmits it to the mobile station through a protocol promised. to be. In other words, the VRS method has the same effect as placing an actual reference station next to a virtual reference station by creating a virtual reference station close to the location of a general user.

However, in order to support the virtual reference station for each user's request, since phase information must be generated for each location of each mobile station, a high-performance server is required, and the number of users that can be supported at the same time is limited according to the performance of the server.

An embodiment of the present invention is to provide a virtual reference station-based real-time positioning method capable of supporting a plurality of users and a virtual reference station server using the same.

A real-time positioning method according to an embodiment of the present invention includes the steps of dividing an area into a plurality of areas; Setting one virtual reference station for each of the plurality of regions, and estimating phase information at the positions of each virtual reference station; Determining in which of the plurality of areas the first mobile station is located based on location information from the first mobile station; And transmitting, to the first mobile station, phase information of a virtual reference station set in an area where the first mobile station is located.

The virtual reference station server according to an embodiment of the present invention divides an area into a plurality of areas based on the positions of the plurality of reference stations, sets one virtual reference station for each of the plurality of areas, and A virtual reference station setting unit estimating phase information at the position of the reference station; An area determination unit that determines in which of the plurality of areas the first mobile station is located based on location information from the first mobile station; And a transmission unit for transmitting phase information of a virtual reference station set in an area in which the first mobile station is located to the first mobile station.

A real-time positioning system according to an embodiment of the present invention includes: a plurality of reference stations having a known location and receiving satellite data from a GNSS satellite; A virtual reference for dividing an area into a plurality of areas based on the positions of the plurality of reference stations, setting one virtual reference station for each of the plurality of areas, and estimating phase information at the locations of each virtual reference station Bureau server; And a mobile station providing location information to the virtual reference station, wherein the virtual reference station server determines in which area of the plurality of areas the mobile station is located based on the location information from the mobile station, and the mobile station The phase information of the virtual reference station set in the location area is transmitted to the mobile station, and the mobile station performs real-time positioning based on the phase information transmitted from the virtual reference station server and satellite data from the GNSS satellite.

According to an embodiment of the present invention, it is possible to support a plurality of users (mobile stations) for one virtual reference station.

1 is a diagram showing a real-time positioning system according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining a plurality of reference stations of FIG. 1.
3 is a flowchart illustrating a real-time positioning method performed in the real-time positioning system of FIG. 1.
4(a), 4(b), and 4(c) are diagrams for explaining a region division step of FIG. 3, a virtual reference station setting and phase information estimation step.
FIG. 5 is a diagram for describing a phase information estimation step of FIG. 3.
6(a) is a view for explaining a virtual reference station according to the prior art, and FIG. 6(b) is a view for explaining a virtual reference station according to an embodiment of the present invention.
7 is a diagram showing the structure of a VRS server according to an embodiment of the present invention.

Based on the principle that the inventor can appropriately define the concept of terms in order to describe his own invention in the best way, terms or words used in the present specification and claims are consistent with the technical idea of the present invention. It should be interpreted as meaning and concept.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary. In addition, terms such as "...unit", "...group", "module", and "device" described in the specification mean units that process at least one function or operation, which is a combination of hardware or software or hardware and software. It can be implemented as

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram showing a real-time positioning system 10 according to an embodiment of the present invention.

Referring to FIG. 1, the real-time positioning system 10 includes a GNSS satellite 100 for transmitting satellite data, a plurality of reference stations 210 and 220 for receiving satellite data from the GNSS satellite 100 with known actual locations. 230), a VRS server 300 that generates error information for the mobile station 400 based on satellite data, and a mobile station 400 that performs real-time positioning using the error information received from the VRS server 300 do.

The GNSS satellite 100 is a satellite on Earth orbit that transmits satellite data to determine a user's location in a Global Navigation Satellite System (GNSS). Theoretically, the position of the mobile station 400 can be accurately calculated with only satellite data transmitted from the GNSS satellite 100, but in reality, various factors such as satellite clock error, satellite orbit error, ionospheric delay error, convective layer error, and multipath error This causes an error. Therefore, work is required to correct this error.

The plurality of reference stations 210, 220, and 230 receive satellite data from the GNSS satellite 100 and transmit the data to the VRS server 300, and their positions are known in advance. The plurality of reference stations 210, 220, and 230 may be, for example, a GPS station operated by the National Geographic Information Institute.

The VRS server 300 divides the region into a plurality of regions based on the locations of the plurality of reference stations 210, 220, 230, sets one virtual reference station for each of the plurality of regions, and sets each virtual reference station. The phase information at the position of the reference station is estimated. Further, the VRS server 300 determines which of the plurality of areas the mobile station belongs to based on the location of the mobile station 400, and transmits the phase information of the virtual reference station set in the corresponding area to the mobile station 400.

The mobile station 400 performs real-time positioning based on the phase information of the mobile station 400 transmitted from the VRS server 300 and satellite data received from the GNSS satellite 100.

FIG. 2 is a diagram for explaining a plurality of reference stations of FIG. 1.

The plurality of reference stations 200 are, for example, GPS observation stations operated by the National Geographic Information Institute, and may be located at locations indicated by dots in FIG. 2. Since it costs a lot to install the reference stations 200, a limited number of reference stations 120 are installed. The plurality of reference stations 210, 220, and 230 of FIG. 1 may be three adjacent reference stations 200 of FIG. 2.

3 is a flow chart showing a real-time positioning method performed by the VRS server 300 of FIG. 1.

Referring to FIG. 3, first, the VRS server 300 divides a serviceable area into a plurality of areas (S100). For example, the serviceable area may be all over Korea. The plurality of regions may have the same shape, such as a circle, a square, or a hexagon. Also, a plurality of areas may be set to have the same area. The radius of each area may be several kilometers, i.e., 1 to 9 kilometers.

Next, the VRS server 300 sets one virtual reference station for each of the plurality of areas, and generates phase information at the locations of the virtual reference stations in each area (S200). For example, the virtual reference station may be located at the center of each area. Here, the phase information may include error information.

Next, the VRS server 300 determines which of the plurality of areas set in step S200 is located in the mobile station 400 based on the location information from the mobile station 400 (S300).

Next, the VRS server 300 transmits the phase information of the virtual reference station in the region to which the mobile station 400 belongs to the mobile station 400 (S400).

Finally, the mobile station 400 performs real-time positioning based on the phase information transmitted from the VRS server 300 (S500).

4(a), 4(b), and 4(c) are diagrams for explaining a region division step (S100) of FIG. 3 and a virtual reference station setting and phase information estimation step (S200).

The VRS server 300 divides a serviceable area into a plurality of areas. Each region can have the same shape and size. Each region may have a hexagonal shape as shown in FIG. 4(a), may have a circular shape as shown in FIG. 4(b), or have a rectangular shape as shown in FIG. 4(c). It can also have a shape. However, this is only an example, and a plurality of regions may have different shapes. As illustrated in FIGS. 4A and 4C, each region may be set so as not to overlap, or two or more regions may be set to overlap as illustrated in FIG. 4B. The radius of the plurality of regions may be, for example, 1 to 9 kilometers. In FIGS. 4(b) and 4(c), the distance from the center of each area to the vertex may be 1 to 9 kilometers.

The VRS server 300 sets one virtual reference station for each area. In Figs. 4(a), 4(b), and 4(c), triangle marks indicate virtual reference stations. For example, the virtual reference station may be located at the center of each area.

In the embodiment of the present invention, the location of the virtual reference station has a preset location regardless of the location of the mobile station 400. The location of the virtual reference station may be set based on the location of the reference station in FIG. 2. Accordingly, since the VRS server 300 only needs to generate phase information for a virtual reference station at a preset location, it is possible to quickly generate phase information.

FIG. 5 is a diagram for describing a phase information estimation step S200 of FIG. 3. In Fig. 5, the triangle marks indicate virtual reference stations.

Referring to FIG. 5, the VRS server 300 estimates error information at the location of the virtual reference station by using the error information at the location of the reference stations 210, 220, and 230. At this time, the VRS server 300 generates a linear interpolation plane (Dillowney triangle) using the error information at the location of the reference stations 210, 220, and 230, thereby estimating the error information at the location of the virtual reference station. I can. Then, phase information including such error information is generated for each virtual reference station.

6(a) is a view for explaining a virtual reference station according to the prior art, and FIG. 6(b) is a view for explaining a virtual reference station according to an embodiment of the present invention. In Figs. 6(a) and 6(b), a circle indicates a location of a mobile station, and a triangle indicates a location of a virtual reference station.

Referring to FIG. 6A, in the related art, a VRS server sets a virtual reference station for each location of the mobile station 400, and generates error information based on the set location of the virtual reference station. That is, the virtual reference station and the mobile station were matched 1:1. Therefore, since the VRS server must set virtual reference stations for all mobile stations 400 and calculate phase information according to the positions of the set virtual reference stations, high performance is required for the VRS server and the mobile stations that can serve at the same time The number was limited.

However, according to the embodiment of the present invention, phase information generated based on the position of the same virtual reference station is transmitted to the mobile station 400 belonging to the same area. That is, as shown in FIG. 6(b), even if a plurality of mobile stations 400 exist in the same area indicated by a dotted line, the phase information generated based on the position of one virtual reference station is transmitted to the plurality of mobile stations 400. ). In other words, the virtual reference station and the mobile station are matched in 1:N. Therefore, according to the embodiment of the present invention, the VRS server 300 does not need to be of high performance, and it is possible to service many mobile stations 400 at once.

7 is a diagram showing the structure of a VRS server 300 according to an embodiment of the present invention.

Referring to FIG. 7, the VRS server 300 divides an area into a plurality of areas based on the positions of the plurality of reference stations, sets one virtual reference station for each of the plurality of areas, and sets each virtual reference station. A virtual reference station setting unit 310 for estimating phase information at the location of the station; An area determination unit (320) for determining which of the plurality of areas the first mobile station is located based on location information from the first mobile station; And a transmission unit 330 that transmits phase information of a virtual reference station set in an area in which the first mobile station is located to the first mobile station.

The virtual reference station setting unit 310 performs the region classification step (S100) of FIG. 3 and the virtual reference station setting and phase information estimation step (S200), and the region determination unit 320 includes the region determination step ( S300), and the transmission unit 330 performs a phase information transmission step (S400). Since the operations of each of the steps S100 to S400 have already been described with reference to FIG. 3, duplicate descriptions are omitted.

As described above, the present invention has been described in detail through preferred embodiments, but the present invention is not limited thereto, and various modifications and applications can be made within the scope of the technical spirit of the present invention. It is self-explanatory to the technician. Therefore, the true scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

For example, in FIG. 4B, it is illustrated that a plurality of regions overlap each other only when a plurality of regions have a circular shape. However, even if a plurality of regions have different shapes, they may overlap each other.

In addition, the plurality of regions may have different shapes as well as the shapes of FIGS. 4(a), 4(b), or 4(c), and the sizes of the plurality of regions may be different from each other.

Claims (9)

Setting a plurality of regions such that each maximum length is less than a distance between two adjacent reference stations;
Setting one virtual reference station at each fixed location of the plurality of regions and estimating phase information at the location of each virtual reference station;
Determining in which of the plurality of areas the first mobile station is located based on location information from the first mobile station; And
Transmitting phase information of a virtual reference station set in an area where the first mobile station is located to the first mobile station
Real-time positioning method comprising a. The method of claim 1,
Determining in which of the plurality of areas the second mobile station is located based on location information from the second mobile station; And
When it is determined that the second mobile station is located in the same area as the area in which the first mobile station is located, phase information estimated based on the position of the virtual reference station corresponding to the first mobile station is transmitted to the second mobile station. Steps to
Real-time positioning method further comprising a. The method of claim 1,
The real-time positioning method, characterized in that the plurality of areas have the same area. The method of claim 1,
The real-time positioning method, characterized in that each of the plurality of regions are circular, hexagonal or rectangular. The method of claim 1,
The plurality of regions are circular,
Adjacent areas overlap each other,
When the first mobile station is located in the overlapping area, the error information of the first mobile station is calculated based on the position of any one of the virtual reference stations set in the areas corresponding to the overlapping area. Positioning method. A plurality of areas are set so that each maximum length is less than the distance between two adjacent reference stations, one virtual reference station is set at each fixed position of the plurality of areas, and at the position of each virtual reference station A virtual reference station setting unit that estimates phase information;
An area determination unit that determines in which of the plurality of areas the first mobile station is located based on location information from the first mobile station; And
A transmission unit for transmitting phase information of a virtual reference station set in an area in which the first mobile station is located to the first mobile station
Virtual reference station server comprising a. The method of claim 6,
The area determination unit,
Determining in which of the plurality of areas the second mobile station is located based on the location information from the second mobile station,
The transmission unit,
When it is determined that the second mobile station is located in the same area as the area in which the first mobile station is located, phase information estimated based on the position of the virtual reference station corresponding to the first mobile station is transmitted to the second mobile station. Virtual reference station server, characterized in that. A plurality of reference stations of known location and receiving satellite data from GNSS satellites;
A plurality of areas are set so that the maximum length of each is less than the distance between two adjacent reference stations among the plurality of reference stations, and one virtual reference station is set at each fixed position of the plurality of areas, and each A virtual reference station server for estimating phase information at the location of the virtual reference station; And
Mobile station providing location information to the virtual reference station
Including,
The virtual reference station server determines which of the plurality of areas the mobile station is located in based on the location information from the mobile station, and sends the phase information of the virtual reference station set in the area where the mobile station is located to the mobile station. Transfer,
The mobile station, a real-time positioning system for performing real-time positioning based on the phase information received from the virtual reference station server and satellite data from the GNSS satellite. The method of claim 8,
The virtual reference station server, when two mobile stations located at different locations belong to the same area, transmits phase information estimated based on the positions of the same virtual reference stations to the two mobile stations.

Images