Method for applying GPS static measurement result conversion parameters to RTK measurement

Abstract

The invention discloses a method for applying GPS static measurement result conversion parameters to RTK measurement, and belongs to the technical field of engineering measurement. The method comprises the following steps: S1, carrying out synchronous static observation on a CPII control network in a measurement area by adopting a plurality of double-frequency GPS receivers, constructing a network in an edge-connected manner, calculating a baseline vector grid-connected adjustment, and obtaining a three-dimensional coordinate of a control point WGS-84; s2, the digital level gauge carries out fourth level measurement, height difference is rechecked and adjusted, and normal height is obtained; s3, performing segmented area measurement, solving plane conversion parameters based on WGS-84 coordinates and engineering coordinates, and solving elevation conversion parameters by combining geodetic height and normal height; s4, calculating an inspection plane residual error and an elevation residual error; and S5, importing the parameters into RTK equipment, erecting the base station at any control point, and performing real-time dynamic measurement by the moving station. According to the method for applying the GPS static measurement result conversion parameters to RTK measurement, the base station can be flexibly erected, site point correction is not needed, and efficiency and precision are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering surveying, and in particular relates to a method for converting parameters of GPS static survey results for RTK surveying. Background Art

[0002] In the roadbed construction of linear projects such as railways and highways, the surveying work runs through key links such as cross-section measurement of the original mud surface, stake layout in the line, backfill or excavation edge layout and layered elevation control, which plays a decisive role in the control of construction progress and quality.

[0003] In the existing technology, engineering surveying needs to solve the problem of coordinate system conversion, that is, converting the WGS-84 coordinate system coordinates into the engineering coordinate system coordinates to meet the needs of layout and control. The traditional operation method relies on surveyors to use on-site point correction to obtain conversion parameters. This process requires full-time operation, which has the problems of high work intensity and low efficiency. At the same time, on-site correction is significantly affected by observation conditions, which can easily lead to uneven measurement accuracy, and the accuracy loss is relatively fast during the extrapolation process. There is a risk of quality accidents such as inconsistent roadbed structure dimensions and out-of-control elevation due to positioning deviations.

[0004] How to improve the efficiency of linear engineering roadbed construction measurement and reduce the risk of human operation while ensuring the uniformity and reliability of measurement accuracy is a technical problem that needs to be solved urgently in this field. Summary of the invention

[0005] In view of the deficiencies existing in the related art, the purpose of the present invention is to provide a method for converting parameters of GPS static measurement results for RTK measurement, so as to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions: A method for converting parameters of GPS static measurement results for use in RTK measurement, comprising: S1. Static measurement data collection and processing Multiple dual-frequency GPS receivers are used to conduct synchronous static observations of the CPII control network in the survey area. The edge-connected network is used to form a strip control network. The baseline vector is solved and the network adjustment is performed through data processing software to obtain the three-dimensional coordinates of the control points in the WGS-84 coordinate system, including latitude, longitude and geodetic height. S2. Leveling data collection and processing Use a digital level to conduct fourth-order leveling of the leveling points in the survey area, check the height difference and adjust it to obtain the normal height of the control points; S3. Conversion parameter solution The survey area is segmented into multiple survey sections, and the plane transformation parameters of each survey section are solved based on the WGS-84 coordinates of step S1 and the coordinates of the known points in the engineering coordinate system of the survey area; the elevation transformation parameters of each survey section are solved by combining the geoid height of step S1 and the normal height of step S2; S4. Parameter validity test Calculate the plane residual and elevation residual of known control points in each measuring section to ensure that the plane residual is less than 15mm and the elevation residual is not more than 20mm; S5, RTK measurement application The verified conversion parameters of each survey section are imported into the RTK equipment. The base station is set up at any control point in the control network of the corresponding survey section. The mobile station does not need on-site point correction and can directly perform real-time dynamic measurement.

[0007] In some of the embodiments, in step S1, six GEOMAX dual-frequency GPS receivers are used for synchronous static observation, and a strip control network with geodetic quadrilaterals as basic units is formed through edge-connected networking, covering a survey area with a length of not less than 90 kilometers. Baseline solution and network adjustment are performed through Leica LGO software to obtain three-dimensional coordinates of the WGS-84 coordinate system containing not less than 156 control points.

[0008] In some of the embodiments, in step S2, the GEOMAX ZDL700 digital level is used for leveling measurement, the operation is carried out according to the national fourth-class leveling specifications, the leveling network is adjusted through the KOSHA ground control measurement data processing system, the height difference between adjacent leveling points is checked point by point, and the accuracy of the control points is verified.

[0009] In some of the embodiments, in step S3, when solving the plane transformation parameters, for each measurement segment, no less than 3 high-level starting points that are evenly distributed and can control the area of ​​the measurement segment are selected, and a mathematical model is selected to calculate the starting points using a combination of multiple points.

[0010] In some embodiments, in step S3, when solving the elevation conversion parameter, the formula H γ = H 84 - f (x, y) calculates the normal height, where, H 84 is the earth height obtained in step S1, H γ The target is normal high, f (x, y) is the elevation anomaly function of any point (x, y), f (x, y) Select the translation model, plane fitting model or quadratic surface fitting model according to the range of each measuring section.

[0011] In some of the embodiments, in step S3, the basis for segmenting the survey area is the difference in projection parameters of the engineering coordinate system of the survey area, including the central meridian, projection height or construction coordinate system division. When the survey area spans different construction coordinate systems, the survey sections are divided according to the segment mileage provided by the design unit.

[0012] In some of the embodiments, according to the transformation parameters of each measuring section solved in step S3, the WGS-84 coordinate system coordinates of the known control points in each measuring section are substituted into the transformation parameters, the engineering coordinate system coordinates are calculated by the four-parameter method or the seven-parameter method, and then the plane residuals and the elevation residuals are calculated.

[0013] In some embodiments, when the four-parameter method is used, the conversion parameters include the translation parameter △x 1 , translation parameter △y 2 , rotation parameter α and scale parameter m 1 , let WGS-84 coordinates be (x 1 ,y 1 ), convert the engineering coordinates to (x 2 ,y 2 ),but , .

[0014] In some embodiments, when the seven-parameter method is used, the transformation parameters include the translation parameter △x 2 , translation parameter △y 2 , translation parameter △z 2 , rotation parameter ε x , rotation parameter ε y , rotation parameter ε z and scale parameter m 2 , let WGS-84 coordinates be (X 1 ,Y 1 ,Z 1 ), convert the engineering coordinates to (X 2 ,Y 2 ,Z 2 ),but , , .

[0015] In some of the embodiments, in step S5, the RTK measurement application adopts a single base station RTK mode, the base station is set up to meet the requirements of being located at any control point in the corresponding measurement section control network, and the data link communication distance between the base station and the mobile station can ensure the stability of differential data transmission; the mobile station receives the WGS-84 differential observation data of the base station in real time, combines the measurement section conversion parameters, and solves the plane coordinates (x 2 ,y 2 ) and normal high H γ .

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The method for using the GPS static measurement result conversion parameter for RTK measurement provided by the present invention solves the conversion parameter with the help of static measurement control network data. The base station can be set up at any control point in the survey area, and the mobile station does not need to collect data point correction on site, which simplifies the operation process, improves the flexibility of base station setting and the stability of data link signal, ensures uniform measurement accuracy, and avoids the inefficiency and extrapolation accuracy risk of traditional point correction.

[0017] 2. The method for converting GPS static measurement results parameters for RTK measurement provided by the present invention performs segmented adjustment according to the characteristics of different construction coordinate systems, reasonably combines the starting points and optimizes the fitting model, breaks through the limitations of traditional adjustment rules, effectively solves the problem of uneven elevation fitting accuracy in the survey area, and is matched with a lightweight digital level to reduce the intensity of field labor, realize efficient and high-precision measurement of long-distance linear engineering survey areas, and provide technical support for construction progress and quality control. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 The present invention is a flowchart of an embodiment of a method for converting GPS static measurement results into parameters for RTK measurement. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] See attached Figure 1 , gives a schematic embodiment of the method for using the GPS static measurement result conversion parameter for RTK measurement proposed in the present invention. This embodiment is based on a 90-kilometer railway engineering survey area, which spans the third and fourth construction coordinate systems. The central meridian of the third coordinate system is 38°57′ and the projection height is 410 meters. The central meridian of the fourth coordinate system is 38°36′ and the projection height is 550 meters. The elevation system uses the KRC elevation benchmark. The specific steps are as follows: S1. Static measurement data collection and processing Multiple dual-frequency GPS receivers are used to conduct synchronous static observations of the CPII control network in the survey area. The edge-connected network is used to form a strip control network. The baseline vector is solved and the network adjustment is performed through data processing software to obtain the three-dimensional coordinates of the control points in the WGS-84 coordinate system, including latitude, longitude and geodetic height. S2. Leveling data collection and processing Use a digital level to conduct fourth-order leveling of the leveling points in the survey area, check the height difference and adjust it to obtain the normal height of the control points; S3. Conversion parameter solution The survey area is segmented into multiple survey sections, and the plane transformation parameters of each survey section are solved based on the WGS-84 coordinates of step S1 and the coordinates of the known points in the engineering coordinate system of the survey area; the elevation transformation parameters of each survey section are solved by combining the geoid height of step S1 and the normal height of step S2; S4. Parameter validity test Calculate the plane residual and elevation residual of known control points in each measuring section to ensure that the plane residual is less than 15mm and the elevation residual is not more than 20mm; S5, RTK measurement application The verified conversion parameters of each survey section are imported into the RTK equipment. The base station is set up at any control point in the control network of the corresponding survey section. The mobile station does not need on-site point correction and can directly perform real-time dynamic measurement.

[0023] In step S1, six GEOMAX dual-frequency GPS receivers are used for synchronous static observation, and a strip control network with geodetic quadrilaterals as basic units is formed through edge-connected networking, covering a survey area of ​​not less than 90 kilometers in length, and baseline solution is performed through Leica LGO software, and preliminary solution is performed using broadcast ephemeris, observation data with cycle slip ratio>10 is eliminated, and then secondary solution is performed through precise ephemeris, and finally unconstrained adjustment of the entire network is performed to obtain three-dimensional coordinates of the WGS-84 coordinate system containing not less than 156 control points. In this embodiment, when constructing the network, the number of overlapping edges of adjacent geodetic quadrilaterals is ≥2, ensuring that the control network strength factor (PDOP) is ≤4, and the reliability of baseline solution is improved through redundant observation.

[0024] In some of the embodiments, in step S2, a GEOMAX ZDL700 digital level (nominal accuracy: 0.7mm / km height difference error) and a matching barcode leveling ruler are used to implement round-trip measurement in accordance with the "National Third and Fourth Class Leveling Specifications", with the sight length of the measuring station ≤80 meters and the front and rear sight difference ≤3 meters. The leveling network is adjusted through the Kesha ground control measurement data processing system, and the height difference of adjacent leveling points is checked point by point to verify the accuracy of the control points. First, the 20 first-level leveling points transferred by the design unit are re-measured, and the abnormal points with height difference closure error >±12√L (L is the route length, km) are eliminated, and then the 89-kilometer leveling route in the entire survey area is strictly adjusted to obtain the normal height of the control point (accuracy: ±15mm). Among them, the dynamic differential measurement mode is used for leveling observation, and the ambient temperature and air pressure data of the measuring station are automatically recorded, and the atmospheric refraction difference is corrected in real time through the built-in model of the software.

[0025] In step S3, the basis for segmenting the survey area is the difference in projection parameters of the survey area engineering coordinate system, including the central meridian, projection height or construction coordinate system division. When the survey area spans different construction coordinate systems, the survey sections are divided according to the segment mileage provided by the design unit. In this embodiment, the survey area is divided into two main sections according to the difference in projection parameters of the construction coordinate system: the third coordinate system (62 control points) and the fourth coordinate system (49 control points). In view of the problem of insufficient elevation accuracy of the third coordinate system, it is further divided into 3 sub-sections (each section is about 15 kilometers), and each sub-section is evenly distributed with 4 CPI starting points (including plane + elevation coordinates) and 3 encrypted elevation starting points verified by leveling.

[0026] In step S3, when solving the plane transformation parameters, for each measurement section, select no less than 3 high-level starting points (including two sets of coordinate results of the WGS-84 coordinate system and the engineering coordinate system) that are evenly distributed and can control the area of ​​the measurement section, select a mathematical model to calculate the starting points in a variety of point combinations, and optimize the calculated starting points. In this embodiment, for each measurement section, select ≥3 high-level starting points (such as CPI control points, which have both WGS-84 coordinates and engineering coordinate system coordinates), and use the least squares method to compare and calculate the four-parameter method with the seven-parameter method.

[0027] Using the four-parameter method, the conversion parameters include the translation parameter △x 1 , translation parameter △y 2 , rotation parameter α and scale parameter m 1 , suitable for small-scale plane conversion (<50km²), first, the preset WGS-84 coordinates are (x 1 ,y 1 ), and the preset conversion engineering coordinates are (x 2 ,y 2 ),So , .

[0028] The seven-parameter method is used, and the conversion parameters include the translation parameter △x 2 , translation parameter △y 2 , translation parameter △z 2 , rotation parameter ε x , rotation parameter ε y , rotation parameter ε z and scale parameter m 2 , let WGS-84 coordinates be (X 1 ,Y 1 ,Z 1 ), convert the engineering coordinates to (X 2 ,Y 2 ,Z 2 ), based on the Bursa model, additionally solve the three-dimensional rotation parameters and translation parameters △z 2 , applicable to cross-projection zone conversion, the conversion formula is as follows: , , Among them, the covariance matrix constraint is introduced into the seven-parameter method to limit the range of variation of the scale parameter m (|m|≤1×10 -6 ), to avoid parameter divergence.

[0029] According to the conversion parameters of each measuring section solved in step S3, the WGS-84 coordinates of the known control points in each measuring section are substituted into the conversion parameters, and the engineering coordinate system coordinates are calculated by the four-parameter method or the seven-parameter method, and then the plane residual and elevation residual are calculated. For each known control point in the measuring section, the WGS-84 coordinates are substituted into the corresponding conversion parameters, and the engineering coordinate system coordinates are calculated and compared with the known values. The plane residual is: |x 2 -x 2 '|<15mm,|y 2 -y 2 '|<15mm; elevation residual: |Hγ-Hγ'|≤20mm. The 3σ rule is used to eliminate gross error points, and the starting points with excessive residuals are re-measured and verified to ensure that the residuals of the control points involved in the parameter solution are better than ±10mm in plane and ±15mm in elevation.

[0030] In step S3, when solving the elevation conversion parameters, the formula H γ = H 84 - f (x, y) calculates the normal height, where, H 84 is the earth height obtained in step S1, H γ The target is normal high, f (x, y) is the elevation anomaly function of any point (x, y), f (x, y) Select the translation model or plane fitting model or quadratic surface fitting model according to the area range of each measurement section. In this embodiment, for the elevation anomaly model of each measurement area, the fourth coordinate system adopts the plane fitting model: ζ=a+bx+cy, which is suitable for areas with terrain undulation ≤50 meters, while the third coordinate system sub-section adopts the quadratic surface fitting model: ζ=a+bx+cy+dx²+exy+fy² due to the complex terrain, and the fitting accuracy under complex terrain is improved by adding the quadratic term.

[0031] In step S5, the RTK measurement application adopts the single-base RTK mode. The base station is set up to meet the requirements of being located at any control point in the corresponding survey section control network, and the data link communication distance between the base station and the mobile station can ensure the stability of differential data transmission; the mobile station receives the WGS-84 differential observation data of the base station in real time, and combines the survey section conversion parameters to solve the plane coordinates (x 2 ,y 2 ) and normal high H γ .

[0032] First, select any CPII control point (such as CPI032) within the survey section to set up the base station, install an omnidirectional antenna with an elevation angle ≥15°, set the data link transmission frequency (450MHz), and the communication distance coverage radius ≤10 kilometers (adjusted according to the terrain) to ensure that the differential signal is stable and uninterrupted. Then, after the mobile station is turned on, it automatically obtains the differential data of the base station, combines the survey section conversion parameters, and solves the engineering coordinate system coordinates in real time: for plane coordinate conversion, the WGS-84 plane / space rectangular coordinates are converted to the construction coordinate system coordinates through the four-parameter method or the seven-parameter method; for elevation conversion, according to the elevation anomaly model of the survey section, the geodetic height H 84 Calculate normal high H γ The mobile station has a built-in anti-multipath antenna, combined with the narrowband filtering technology of the RTK equipment, to suppress signal interference in urban canyon or mountainous environments, ensuring that the fixed solution convergence time is ≤30 seconds. Finally, two known control points are randomly selected for each survey section for accuracy verification. The deviation between the measured coordinates and the designed coordinates must meet the requirements of ≤15mm in plane and ≤20mm in elevation. Large-scale stakeout operations can only be carried out after the verification is passed.

[0033] In the above-mentioned schematic embodiment, the method of converting GPS static measurement results into parameters for RTK measurement uses static measurement control network data to solve the conversion parameters. The base station can be set up at any control point in the survey area, and the mobile station does not need to collect data on-site for point correction, which simplifies the operation process, improves the flexibility of base station installation and data link signal stability, ensures uniform measurement accuracy, and avoids the inefficiency and extrapolation accuracy risks of traditional point correction.

[0034] Finally, it should be noted that: the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0035] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A method for converting GPS static measurement results into parameters for RTK measurement, characterized in that: include: S1. Static measurement data collection and processing Multiple dual-frequency GPS receivers are used to conduct synchronous static observations of the CPII control network in the survey area. The edge-connected network is used to form a strip control network. The baseline vector is solved and the network adjustment is performed through data processing software to obtain the three-dimensional coordinates of the control points in the WGS-84 coordinate system, including latitude, longitude and geodetic height. S2. Leveling data collection and processing Use a digital level to conduct fourth-order leveling of the leveling points in the survey area, check the height difference and adjust it to obtain the normal height of the control points; S3. Conversion parameter solution The survey area is segmented into multiple survey sections, and the plane transformation parameters of each survey section are solved based on the WGS-84 coordinates of step S1 and the coordinates of the known points in the engineering coordinate system of the survey area; the elevation transformation parameters of each survey section are solved by combining the geoid height of step S1 and the normal height of step S2; S4. Parameter validity test Calculate the plane residual and elevation residual of known control points in each measuring section to ensure that the plane residual is less than 15mm and the elevation residual is not more than 20mm; S5, RTK measurement application The verified conversion parameters of each survey section are imported into the RTK equipment. The base station is set up at any control point in the control network of the corresponding survey section. The mobile station does not need on-site point correction and can directly perform real-time dynamic measurement.

2. The method for using the GPS static measurement result conversion parameters for RTK measurement according to claim 1, characterized in that: In step S1, six GEOMAX dual-frequency GPS receivers are used for synchronous static observation. A strip control network with geodetic quadrilaterals as basic units is formed through edge-connected network construction, covering a survey area of ​​no less than 90 kilometers in length. Baseline solution and network adjustment are performed through Leica LGO software to obtain three-dimensional coordinates of the WGS-84 coordinate system containing no less than 156 control points.

3. The method for using the GPS static measurement result conversion parameters for RTK measurement according to claim 1, characterized in that: In step S2, GEOMAX ZDL700 digital level is used for leveling measurement according to the national fourth-class leveling specifications. The leveling network is adjusted through the KOSHA ground control measurement data processing system, and the height difference between adjacent leveling points is checked point by point to verify the accuracy of the control points.

4. The method for using the GPS static measurement result conversion parameter for RTK measurement according to claim 1, characterized in that: In step S3, when solving the plane transformation parameters, for each measurement section, no less than 3 high-level starting points that are evenly distributed and can control the area of ​​the measurement section are selected, and a mathematical model is selected to calculate the starting points using a combination of multiple points.

5. The method for using the GPS static measurement result conversion parameters for RTK measurement according to claim 1, characterized in that: In step S3, when solving the elevation conversion parameters, the formula H γ = H 84 - f (x, y) calculates the normal height, where, H 84 is the earth height obtained in step S1, H γ The target is normal high, f (x, y) is the elevation anomaly function of any point (x, y), f (x, y) Select the translation model, plane fitting model or quadratic surface fitting model according to the range of each measuring section.

6. The method for using the GPS static measurement result conversion parameters for RTK measurement according to claim 1, characterized in that: In step S3, the survey area is segmented based on the differences in projection parameters of the survey area engineering coordinate system, including the central meridian, projection height or construction coordinate system division. When the survey area spans different construction coordinate systems, the survey sections are divided according to the segment mileage provided by the design unit.

7. The method for using the GPS static measurement result conversion parameters for RTK measurement according to claim 1, characterized in that: According to the conversion parameters of each measuring section solved in step S3, the WGS-84 coordinate system coordinates of the known control points in each measuring section are substituted into the conversion parameters, the engineering coordinate system coordinates are calculated by the four-parameter method or the seven-parameter method, and then the plane residual and the elevation residual are calculated.

8. The method for using the GPS static measurement result conversion parameters for RTK measurement according to claim 7, characterized in that: When the four-parameter method is used, the conversion parameters include translation parameter △x1, translation parameter △y2, rotation parameter α and scale parameter m1. Suppose the WGS-84 coordinate is (x1, y1) and the conversion engineering coordinate is (x2, y2), then , .

9. The method for using the GPS static measurement result conversion parameters for RTK measurement according to claim 7, characterized in that: When the seven-parameter method is used, the transformation parameters include translation parameter △x2, translation parameter △y2, translation parameter △z2, rotation parameter ε x , rotation parameter ε y , rotation parameter ε z and scale parameter m2, assuming the WGS-84 coordinates are (X1, Y1, Z1) and the converted engineering coordinates are (X2, Y2, Z2), then , , .

10. The method for using GPS static measurement result conversion parameters for RTK measurement according to claim 1, characterized in that: In step S5, the RTK measurement application adopts the single base station RTK mode. The base station is set up to meet the requirements of being located at any control point in the corresponding survey section control network, and the data link communication distance between the base station and the mobile station can ensure the stability of differential data transmission; the mobile station receives the WGS-84 differential observation data of the base station in real time, and combines the survey section conversion parameters to solve the plane coordinates (x2, y2) and normal height of the engineering coordinate system in real time. H γ .

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