Multi-satellite-based enhanced ionosphere correction mixed use method and system

Abstract

The invention discloses a multi-satellite-based enhanced ionosphere correction mixed use method and system, and relates to the satellite navigation positioning technology, and the method comprises the following steps: calculating the position of a puncture point; determining the used ionosphere grid points according to the calculated positions of the puncture points; calculating an interpolation coefficient according to the used ionosphere grid points; and according to the obtained interpolation coefficient and the used ionosphere grid point, determining the ionosphere correction number at the puncture point. According to the method provided by the invention, the ionosphere correction broadcasted by each SBAS is weighted in the overlapping area covered by each SBAS service, so that the mixed use of the ionosphere correction is realized, the ionosphere monitoring effect of the monitoring station layout boundary area is improved, and the positioning precision of users in the area is improved.

Description

Technical Field

[0001] The present application relates to the field of satellite technology, and in particular to a method and system for hybrid use of multi-satellite-based enhanced ionospheric correction numbers. Background Art

[0002] The Satellite Based Augmentation System (SBAS) monitors the ionosphere within the coverage area through a certain number of ground monitoring stations, and improves the positioning accuracy of single-frequency users by broadcasting ionospheric correction numbers at grid points.

[0003] SBAS are independently built by each country or region. Since monitoring stations are only deployed in limited areas and the monitoring station data of each SBAS cannot interact, they can only monitor the ionosphere above the area covered by each monitoring station, resulting in poor ionosphere monitoring effect in the boundary area where the monitoring station is deployed. Since the SBAS systems of various countries are designed and built in accordance with ICAO standards, the ionospheric correction numbers are also broadcast according to the same space signal interface file. There is a large overlap in the service range of each SBAS. In the overlapping area at the boundary, the ionospheric correction numbers broadcast by multiple satellite-based augmentation systems can be mixed and used to improve the positioning accuracy of users in the area.

[0004] At present, the ionospheric correction numbers of each SBAS are used independently, and there is still a lack of methods to mix and use multiple SBAS ionospheric correction numbers in areas where SBAS service coverage overlaps.

[0005] Currently, SBAS ionosphere monitoring depends on the distribution of ground monitoring stations. The monitoring station data of each SBAS system cannot interact, and can only monitor the ionosphere above the coverage area of ​​each monitoring station, resulting in poor ionosphere monitoring effect in the boundary area where the monitoring stations are deployed. Summary of the invention

[0006] The embodiment of the present application provides a method and system for mixed use of multi-satellite-based enhanced ionospheric correction numbers, which are used to weight the ionospheric correction numbers broadcast by each SBAS in the overlapping area covered by each SBAS service, realize the mixed use of ionospheric correction numbers, improve the ionospheric monitoring effect in the boundary area where the monitoring station is deployed, and improve the positioning accuracy of users in the area.

[0007] The present application provides a method for hybrid use of multi-satellite-based enhanced ionospheric correction numbers, comprising the following steps:

[0008] Calculate the puncture point location;

[0009] Determine the ionospheric grid point to be used based on the calculated puncture point position;

[0010] Calculate interpolation coefficients based on the ionospheric grid points used;

[0011] The ionospheric correction at the puncture point is determined based on the interpolation coefficients obtained and the ionospheric grid points used.

[0012] Optionally, calculating the puncture point location includes:

[0013] Calculate the latitude of the puncture point φ pp :

[0014] φ pp =sin -1 (sinφ u cosψ pp +cosφ u sinψ pp cos A) (1)

[0015]

[0016] Among them, A is the azimuth; E is the elevation; R e is the radius of the Earth; h I is the height of the maximum electron density layer; φ u is the user ellipsoid latitude;

[0017] Calculate the longitude λ of the puncture point pp :

[0018] In φ u >70° and tanψ pp cos A>tan(π / 2-φ u ) or φ u <-70° and tanψ pp cos(A+π)>tan(π / 2+φ u ), λ pp satisfy:

[0019]

[0020] In other cases, λ pp satisfy:

[0021]

[0022] λ pp represents the longitude of the puncture point, λ u Represents the user ellipsoid longitude.

[0023] Optionally, based on the calculated puncture point position, the ionospheric grid points used are determined to include:

[0024] According to the shape of the area formed by the grid points around the puncture point and the IGP mask, a corresponding number of grid points are selected.

[0025] Optionally, according to the calculated puncture point position, determining the ionospheric grid point to be used also includes:

[0026] For the puncture points at 85°N and 85°S, multiple grid points on the fixed meridians are selected, otherwise the ionospheric corrections are unavailable.

[0027] Optionally, the interpolation coefficients are calculated based on the ionospheric grid points used, including:

[0028] When the puncture point is between 85°N and 85°S, the interpolation coefficient x pp and pp satisfy:

[0029]

[0030]

[0031] Δλ pp =λ pp -λ1 (7)

[0032] Δφ pp =φ pp -φ1 (8)

[0033] Among them, λ1 is the longitude of the grid point to the west of the puncture point; λ2 is the longitude of the grid point to the east of the puncture point; φ1 is the latitude of the grid point to the south of the puncture point; φ2 is the latitude of the grid point to the north of the puncture point;

[0034] When the puncture point is located at 85° north latitude or 85° south latitude, the interpolation coefficient x pp and pp satisfy:

[0035]

[0036]

[0037] Among them, λ3 is the longitude of the nearest grid point to the west of the puncture point.

[0038] Optionally, determining the ionospheric correction number at the puncture point based on the obtained interpolation coefficient and the ionospheric grid point used includes:

[0039] For the same grid point i, the ionospheric corrections of multiple satellite-based augmentation systems at the grid point are weighted and fused. The ionospheric correction number τ after fusion at grid point i is vi satisfy:

[0040]

[0041] Among them, GIVEI i，n is the GIVEI value broadcast by the satellite-based augmentation system n at grid point i; τ vi，n is the number of ionospheric corrections broadcast by SBAS n at grid point i; N is the number of SBAS providing effective augmentation services in the user area.

[0042] Optionally, determining the ionospheric correction number at the puncture point based on the obtained interpolation coefficient and the used ionospheric grid point also includes:

[0043] When there are 4 grid points around the puncture point, the ionospheric correction factor τ at the puncture point is vpp (φ pp ,λ pp )satisfy:

[0044]

[0045] W1(x pp ,y pp )=x pp y pp (13)

[0046] W2(x pp ,y pp )=(1-x pp )y pp (14)

[0047] W3(x pp ,y pp )=(1-x pp )(1-y pp ) (15)

[0048] W4(x pp ,y pp )=x pp (1-y pp ) (16)

[0049] When there are three grid points around the puncture point, the ionospheric correction factor τ at the puncture point is vpp (φ pp ,λ pp )satisfy:

[0050]

[0051] W1(x pp ,y pp )=y pp (18)

[0052] W2(x pp ,y pp )=1-x pp -y pp (19)

[0053] W3(x pp ,y pp )=x pp (20)

[0055] An embodiment of the present application further proposes a system for hybrid use of multi-satellite-based enhanced ionospheric correction numbers, comprising a processor and a memory, wherein a computer program is stored on the memory, and when the computer program is executed by the processor, the steps of the hybrid use method of multi-satellite-based enhanced ionospheric correction numbers are implemented as described above.

[0056] The method of the embodiment of the present application weights the ionospheric correction numbers broadcast by each SBAS in the overlapping area covered by each SBAS service, realizes the mixed use of ionospheric correction numbers, improves the ionospheric monitoring effect in the boundary area where the monitoring station is deployed, and improves the positioning accuracy of users in this area.

[0057] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0059] Figure 1 The following is a schematic diagram of the basic process of the method for mixed use of multi-satellite-based enhanced ionospheric correction numbers according to an embodiment of the present application. DETAILED DESCRIPTION

[0060] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0061] The present application embodiment provides a method for hybrid use of multiple satellite-based enhanced ionospheric correction numbers, such as Figure 1As shown, the following steps are included:

[0062] In step S101, the puncture point position is calculated. In some embodiments, calculating the puncture point position includes:

[0063] Calculate the latitude of the puncture point φ pp (Unit: radians):

[0064] φ pp =sin -1 (sinφ u cosψ pp +cosφ u sinψ pp cos A) (1)

[0065]

[0066] Among them, A is the azimuth; E is the elevation; R e is the radius of the earth, 6378.1363km; h I is the height of the maximum electron density layer, 350km; φ u is the user ellipsoid latitude.

[0067] Calculate the longitude λ of the puncture point pp (Unit: radians):

[0068] In φ u >70° and tanψ pp cos A>tan(π / 2-φ u ) or φ u <-70° and tanψ pp cos(A+π)>tan(π / 2+φ u ), λ pp satisfy:

[0069]

[0070] In other cases, λ pp satisfy:

[0071]

[0072] λ pp represents the longitude of the puncture point, λ u Represents the user ellipsoid longitude.

[0073] In step S102, the ionospheric grid point to be used is determined according to the calculated puncture point position.

[0074] In step S103, interpolation coefficients are calculated according to the used ionospheric grid points.

[0075] In step S104, the ionospheric correction number at the puncture point is determined according to the obtained interpolation coefficient and the used ionospheric grid point. Specifically, according to the obtained interpolation coefficient and the used ionospheric grid point, the ionospheric correction number at the puncture point is determined, which includes:

[0076] For the same grid point i, the ionospheric corrections of multiple satellite-based augmentation systems at the grid point are weighted and fused. The ionospheric correction number τ after fusion at grid point i is vi satisfy:

[0077]

[0078] Among them, GIVEI i，n is the GIVEI value broadcast by the satellite-based augmentation system n at grid point i; τ vi，n is the number of ionospheric corrections broadcast by SBAS n at grid point i; N is the number of SBAS providing effective augmentation services in the user area.

[0079] In some embodiments, determining the ionospheric grid point to be used according to the calculated puncture point position includes:

[0080] According to the shape of the area formed by the grid points around the puncture point and the IGP mask, a corresponding number of grid points are selected. The selection of ionospheric grid points is related to the latitude of the penetration point. An exemplary selection strategy is as follows:

[0081] a) The puncture point is between 60° north and south latitude

[0082] 1) If there are 4 grid points around the puncture point forming a 5°×5° quadrilateral area and the corresponding IGP mask is 1, then these 4 grid points are selected, otherwise the following selection is adopted;

[0083] 2) If there are three grid points around the puncture point forming a 5°×5° triangle area and the corresponding IGP mask is 1, then these three grid points are selected, otherwise the following selection is adopted;

[0084] 3) If there are 4 grid points around the puncture point forming a quadrilateral area of ​​10°×10° and the corresponding IGP mask is 1, then these 4 grid points are selected, otherwise the following selection is adopted;

[0085] 4) If there are three grid points around the puncture point forming a 10°×10° triangle area and the corresponding IGP mask is 1, these three grid points are selected, otherwise the ionospheric correction is considered unavailable.

[0086] b) The puncture point is between 60° and 75° north latitude or between 60° and 75° south latitude

[0087] 1) If there are 4 grid points around the puncture point forming a quadrilateral area of ​​5° (latitude) × 10° (longitude) and the corresponding IGP mask is 1, then these 4 grid points are selected, otherwise the following selection is adopted;

[0088] 2) If there are three grid points around the puncture point forming a triangular area of ​​5° (latitude) × 10° (longitude) and the corresponding IGP mask is 1, then these three grid points are selected, otherwise the following selection is adopted;

[0089] 3) If there are 4 grid points around the puncture point forming a quadrilateral area of ​​10°×10° and the corresponding IGP mask is 1, then these 4 grid points are selected, otherwise the following selection is adopted;

[0090] 4) If there are three grid points around the puncture point forming a 10°×10° triangle area and the corresponding IGP mask is 1, these three grid points are selected, otherwise the ionospheric correction is considered unavailable.

[0091] c) The puncture point is between 75° and 85° north latitude or between 75° and 85° south latitude

[0092] If the two nearest grid points are at 75° latitude and the other two nearest grid points are at 85° latitude (30° longitude apart if band 9 or 10 is used, 90° longitude apart otherwise) and the corresponding IGP mask is 1, a 10°×10° quadrilateral area is constructed by linear interpolation of virtual grid points. These four grid points (virtual grid points) are selected, otherwise the ionospheric correction is considered unavailable.

[0093] In some embodiments, determining the ionospheric grid point to be used according to the calculated puncture point position further includes:

[0094] For the puncture points at 85°N and 85°S, multiple grid points on the fixed meridians are selected, otherwise the ionospheric corrections are unavailable.

[0095] d) The puncture point is at 85°N

[0096] If the four grid points are located at 85°N, 180°W, 90°W, 0°, and 90°E, and the corresponding IGP mask is 1, then these four grid points are selected, otherwise the ionospheric correction is considered unavailable.

[0097] e) The puncture point is at 85° South latitude

[0098] If the four grid points are located at 85°S, 140°W, 50°W, 40°E, and 130°E, and the corresponding IGP mask is 1, then these four grid points are selected, otherwise the ionospheric correction is considered unavailable.

[0099] In some embodiments, calculating interpolation coefficients based on the used ionospheric grid points includes:

[0100] When the puncture point is between 85°N and 85°S, the interpolation coefficient x pp and pp satisfy:

[0101]

[0102]

[0103] Δλ pp =λ pp -λ1 (7)

[0104] Δφ pp =φ pp -φ1 (8)

[0105] Among them, λ1 is the longitude of the grid point to the west of the puncture point; λ2 is the longitude of the grid point to the east of the puncture point; φ1 is the latitude of the grid point to the south of the puncture point; φ2 is the latitude of the grid point to the north of the puncture point;

[0106] When the puncture point is located at 85° north latitude or 85° south latitude, the interpolation coefficient x pp and pp satisfy:

[0107]

[0108]

[0109] Among them, λ3 is the longitude of the nearest grid point to the west of the puncture point.

[0110] In some embodiments, determining the ionospheric correction number at the puncture point according to the obtained interpolation coefficient and the used ionospheric grid point further includes:

[0111] When there are 4 grid points around the puncture point, the ionospheric correction factor τ at the puncture point is vpp (φ pp ,λ pp )satisfy:

[0112]

[0113] W1(x pp ,y pp )=x pp y pp (13)

[0114] W2(x pp ,ypp )=(1-x pp )y pp (14)

[0115] W3(x pp ,y pp )=(1-x pp )(1-y pp ) (15)

[0116] W4(x pp ,y pp )=x pp (1-y pp ) (16)

[0117] When there are three grid points around the puncture point, the ionospheric correction factor τ at the puncture point is vpp (φ pp ,λ pp )satisfy:

[0118]

[0119] W1(x pp ,y pp )=y pp (18)

[0120] W2(x pp ,y pp )=1-x pp -y pp (19)

[0121] W3(x pp ,y pp )=x pp (20)

[0123] The method of the embodiment of the present application solves the problem of poor ionospheric monitoring effect in the boundary area where the monitoring station is deployed, and can effectively integrate the ionospheric correction numbers of the multi-satellite-based augmentation system. The method of the present application is simple and easy to implement in engineering.

[0124] An embodiment of the present application further proposes a system for hybrid use of multi-satellite-based enhanced ionospheric correction numbers, comprising a processor and a memory, wherein a computer program is stored on the memory, and when the computer program is executed by the processor, the steps of the hybrid use method of multi-satellite-based enhanced ionospheric correction numbers are implemented as described above.

[0125] It should be noted that in the various embodiments of the present application, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0126] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0127] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0128] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A method for mixed use of multi-satellite-based enhanced ionospheric correction numbers, characterized in that: The steps include: Calculate the puncture point location; According to the calculated puncture point position, the ionospheric grid point to be used is determined; Calculate interpolation coefficients based on the ionospheric grid points used; The ionospheric correction at the puncture point is determined based on the interpolation coefficients obtained and the ionospheric grid points used.

2. The method for mixed use of multi-satellite-based enhanced ionospheric correction numbers according to claim 1, characterized in that: Calculation of the puncture point location includes: Calculate the latitude of the puncture point φ pp : f pp =sin -1 (sinφ u cosψ pp +cosφ u sinψ pp cosA) (1) Among them, A is the azimuth; E is the elevation; R e is the radius of the Earth; h I is the height of the maximum electron density layer; φ u is the user ellipsoid latitude; Calculate the longitude λ of the puncture point pp : In φ u >70° and tanφ pp cosA>tan(π / 2-φ u ) or φ u <-70° and tanψ pp cos(A+π)>tan(π / 2+φ u ), λ pp satisfy: In other cases, λ pp satisfy: λ pp represents the longitude of the puncture point, λ u Indicates the user ellipsoid longitude.

3. The method for mixed use of multi-satellite-based enhanced ionospheric correction numbers as claimed in claim 2, characterized in that: Based on the calculated puncture point location, the ionospheric grid points used are determined to include: According to the shape of the area formed by the grid points around the puncture point and the IGP mask, a corresponding number of grid points are selected.

4. The method for mixed use of multi-satellite-based enhanced ionospheric correction numbers as claimed in claim 3, characterized in that: Based on the calculated puncture point position, the ionospheric grid points used are determined to include: For the puncture points at 85°N and 85°S, multiple grid points on the fixed meridians are selected, otherwise the ionospheric corrections are unavailable.

5. The method for mixed use of multi-satellite-based enhanced ionospheric correction numbers as claimed in claim 2, characterized in that: The calculation of the interpolation coefficients based on the ionospheric grid points used includes: When the puncture point is between 85°N and 85°S, the interpolation coefficient x pp and pp satisfy: Dl pp =λ pp -λ1 (7) Df pp =φ pp -φ1 (8) Among them, λ1 is the longitude of the grid point to the west of the puncture point; λ2 is the longitude of the grid point to the east of the puncture point; φ1 is the latitude of the grid point to the south of the puncture point; φ2 is the latitude of the grid point to the north of the puncture point; When the puncture point is located at 85° north latitude or 85° south latitude, the interpolation coefficient x pp and pp satisfy: Among them, λ3 is the longitude of the nearest grid point to the west of the puncture point.

6. The method for mixed use of multi-satellite-based enhanced ionospheric correction numbers as claimed in claim 5, characterized in that: Based on the obtained interpolation coefficients and the ionospheric grid points used, the ionospheric correction number at the puncture point is determined as follows: For the same grid point i, the ionospheric corrections of multiple satellite-based augmentation systems at the grid point are weighted and fused. The ionospheric correction number τ after fusion at grid point i is vi satisfy: Among them, GIVEI i,n is the GIVEI value broadcast by the satellite-based augmentation system n at grid point i; τ vi,n is the number of ionospheric corrections broadcast by SBAS n at grid point i; N is the number of SBAS providing effective augmentation services in the user area.

7. The method for mixed use of multi-satellite-based enhanced ionospheric correction numbers according to claim 6, characterized in that: Based on the interpolation coefficients obtained and the ionospheric grid points used, the ionospheric correction number at the puncture point is determined to include: When there are 4 grid points around the puncture point, the ionospheric correction factor τ at the puncture point is vpp (φ pp ,λ pp )satisfy: W1(x pp ,y pp )=x pp y pp (13) W2(x pp ,and pp )=(1-x pp )and pp (14) W3(x pp ,y pp )=(1-x pp )(1-y pp ) (15) W4(x pp ,y pp )=x pp (1-y pp ) (16) When there are three grid points around the puncture point, the ionospheric correction factor τ at the puncture point is vpp (φ pp ,λ pp )satisfy: W1(x pp ,y pp )=y pp (18) W2(x pp ,and pp )=1-x pp -and pp (19) W3(x pp ,y pp )=x pp (20)。 8. A system for hybrid use of multi-satellite-based enhanced ionospheric correction numbers, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the steps of the method for mixed use of multi-satellite-based enhanced ionospheric correction numbers as described in any one of claims 1 to 7 are implemented.

Images