A method for calculating elevation using total station EDM distance measurement

Abstract

This invention discloses a method for calculating elevation using a total station EDM (Electronic Direct Measurement) system. The method includes: setting up a first centering rod with a first reflecting prism at the point P to be measured; burying three observation piers around the building where the point P is located as measurement points A, B, and C for the total station to observe the point P; setting up ground leveling points BM1, BM2, and BM3 around each measurement point A, B, and C; measuring the coordinates of the measurement points A, B, and C and the elevations BM1, BM2, and BM3 of the leveling points BM1, BM2, and BM3; calculating the coordinates and elevation of the point P based on the coordinates of the measurement points A, B, and C, the "line-of-sight elevations" A, B, and C, and the slope distance between the center of the first reflecting prism at the point P observed by the total station at the measurement points A, B, and C; and subtracting the height of the first centering rod from the obtained elevation of the point P to obtain the actual elevation of the point P. This method has the advantages of being fast and accurate.

Description

Technical Field

[0001] This invention relates to a method suitable for measuring the elevation of the reference cable of a suspension bridge, the top elevation of the pylon of a super-large bridge, and the top elevation of a high-rise building. Specifically, it involves a method for calculating elevation using a total station EDM (Electronic Distance Measuring) for distance measurement. Background Technology

[0002] Currently, the main methods for determining the elevation of measurement points in engineering surveying are leveling and trigonometric leveling.

[0003] Leveling is a method of measuring the elevation of points by using the principle that the line of sight of an instrument is horizontal. It is one of the most important methods of elevation measurement. Its advantage is high measurement accuracy, but its disadvantage is that it cannot measure points with large elevation differences, such as the elevation of the reference cable of a suspension bridge, the elevation of the top of the suspension bridge tower, and the elevation of the roof of a high-rise building, all of which cannot be measured due to the large elevation difference.

[0004] The basic principle of trigonometric leveling is to use a total station to measure the vertical angle and slope distance of points to calculate the elevation of the point to be determined. It is one of the most important methods of elevation measurement. Its advantages include less restriction by terrain conditions, and the ability to conduct measurements even at night when combined with a surveying robot. Disadvantages include the need for forward and backward observations to reduce the impact of atmospheric refraction on accuracy. However, in tasks such as measuring the reference cables of suspension bridges, it is impossible to set up a station on the reference cables, making backward measurements difficult. Furthermore, the vertical angle measurement is significantly affected by near-surface atmospheric refraction and cannot be precisely measured, resulting in large angle measurement errors and difficulty in improving accuracy. Summary of the Invention

[0005] The purpose of this invention is to provide a fast and accurate method for calculating elevation using total station EDM distance measurement.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] The method for calculating elevation using total station EDM distance measurement provided by this invention includes:

[0008] A first centering rod with a first reflecting prism is installed at the point P to be measured; three observation piers are buried in the ground around the building where the point P is located as measurement points A, B, and C for setting up a total station to observe the point P. The three measurement points A, B, and C form a triangle that should include the building. Ground leveling points BM1, BM2, and BM3 are set up around each measurement point A, B, and C respectively. The coordinates of the measurement points A, B, and C and the elevations BM1, BM2, and BM3 of the leveling points BM1, BM2, and BM3 are measured.

[0009] Follow these steps:

[0010] Step 1: Set up a second centering rod with a second reflecting prism at a ground level BM1 near measurement point A. Use the total station at measurement point A to observe the slope distance BM1 and vertical angle BM1 of the center of the second reflecting prism at ground level BM1. Calculate the "line of sight elevation" A of the center of the total station telescope at measurement point A from the slope distance BM1, vertical angle BM1, and elevation BM1. Also, observe the slope distance A of the center of the first reflecting prism at the point to be measured P using the total station at measurement point A.

[0011] Step 2: Move the total station and the second centering rod to the observation pier of measurement point B and the ground leveling point BM2 near measurement point B, respectively. Keep the first centering rod of the point to be measured P station station stationary. Rotate the first reflecting prism to align with the total station of measurement point B. Observe the slope distance BM2 and vertical angle BM2 of the center of the second reflecting prism at the ground leveling point BM2 through the total station of measurement point B. Calculate the "line of sight elevation" B of the telescope center of the total station of measurement point B from the slope distance BM2, vertical angle BM2, and elevation BM2. Observe the slope distance B of the center of the first reflecting prism at the point to be measured P through the total station of measurement point B.

[0012] Step 3: Move the total station and the second centering rod to the observation pier at measurement point C and the ground leveling point BM3 near measurement point C, respectively. Keep the first centering rod at point P station stationary. Rotate the first reflecting prism to align with the total station at measurement point C. Observe the slope distance BM3 and vertical angle BM3 of the center of the second reflecting prism at ground leveling point BM3 through the total station at measurement point C. Calculate the "line of sight elevation" C of the telescope center of the total station at measurement point C from the slope distance BM3, vertical angle BM3, and elevation BM3. Observe the slope distance C of the center of the first reflecting prism at point P station from the total station at measurement point C.

[0013] Step 4: Calculate the coordinates and elevation of the point P to be measured based on the coordinates of measurement points A, B, and C, the "line of sight elevation" A, B, and C, and the slope distance of the center of the first reflecting prism at the point P to be measured as observed by the total station at measurement points A, B, and C respectively.

[0014] Step 5: Subtract the height of the first centering rod from the obtained elevation of the point P to be measured to obtain the actual elevation of the point P to be measured.

[0015] The test point P is made of stainless steel and has a hemispherical top surface.

[0016] The measurement points A, B, and C are constructed using forced centering observation piers, with stainless steel centering plates for mounting the total station installed on the top of each of the three observation piers.

[0017] The coordinates of the measurement points A, B, and C were obtained by measuring and adjusting using a total station using the angle measurement method. The error of the plane point position can be controlled within ±1mm.

[0018] The "line-of-sight elevation" error of the total station at each measurement point A, B, and C, calculated by observing the vertical angle and slant distance, is less than 0.1 mm, indicating high measurement accuracy. The error when using a steel tape measure is generally within 2 mm.

[0019] When the total station performs slope distance observation, the meteorological parameters such as temperature, air pressure, and humidity of the measurement points A, B, C and the point to be measured at the top of the tower P are input into each total station for automatic distance correction. The distance is then corrected by adding distance constants and multiplying constants to accurately obtain the optimal value of each observation slope distance.

[0020] Beneficial effects

[0021] The method of this invention is not affected by the angle measurement error of the total station near the ground layer, nor by the inability to ensure that the upper and lower measuring points are on the same plumb line when the total station is measuring vertically. It takes advantage of the stable and reliable slope distance accuracy of the total station EDM measurement. The elevation can be calculated by measuring the slope distance from different measuring points to the point to be measured. The measurement accuracy is not affected by the error of the vertical angle measurement, so as to achieve the purpose of fast and accurate elevation measurement.

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the measurement point buried on the top of the tower.

[0024] Figure 2 This is a schematic diagram of the measurement point layout.

[0025] Figure 3 This is a schematic diagram of the method for measuring slope distance using a total station EDM. Specific implementation plan

[0026] like Figure 1 — Figure 3 As shown, the method for calculating elevation using total station EDM distance measurement provided by this invention includes:

[0027] A first centering rod with a first reflecting prism is installed at the point P to be measured. The point P to be measured should be made of stainless steel, with a hemispherical top surface and a unique highest point. Three observation piers are buried in the ground around the building where the point P is located, such as a cable tower, as measurement points A, B, and C for setting up a total station to observe the point P. The three measurement points A, B, and C form a triangle that should include the cable tower. The measurement points are in the form of forced centering observation piers. A stainless steel centering plate for installing the total station is set on the top of each of the three observation piers. Ground leveling points BM1, BM2, and BM3 are set within 5-15m of each measurement point A, B, and C. The coordinates of the measurement points A, B, and C and the elevations of the leveling points BM1, BM2, and BM3 are measured. The material of the observation piers is not limited; cement or steel can be used.

[0028] Step 1: Set up a second centering rod with a second reflecting prism at a ground level BM1 near measurement point A. Use the total station at measurement point A to observe the slope distance BM1 and vertical angle BM1 of the center of the second reflecting prism at ground level BM1. Calculate the "line of sight elevation" A of the center of the total station telescope at measurement point A from the slope distance BM1, vertical angle BM1, and elevation BM1. Also, observe the slope distance A of the center of the first reflecting prism at the point to be measured P using the total station at measurement point A.

[0029] Step 2: Move the total station and the second centering rod to the observation pier of measurement point B and the ground leveling point BM2 near measurement point B, respectively. Keep the first centering rod of the point to be measured P station station stationary. Rotate the first reflecting prism to align with the total station of measurement point B. Observe the slope distance BM2 and vertical angle BM2 of the center of the second reflecting prism at the ground leveling point BM2 through the total station of measurement point B. Calculate the "line of sight elevation" B of the telescope center of the total station of measurement point B from the slope distance BM2, vertical angle BM2, and elevation BM2. Observe the slope distance B of the center of the first reflecting prism at the point to be measured P through the total station of measurement point B.

[0030] Step 3: Move the total station and the second centering rod to the observation pier at measurement point C and the ground leveling point BM3 near measurement point C, respectively. Keep the first centering rod at point P station stationary. Rotate the first reflecting prism to align with the total station at measurement point C. Observe the slope distance BM3 and vertical angle BM3 of the center of the second reflecting prism at ground leveling point BM3 through the total station at measurement point C. Calculate the "line of sight elevation" C of the telescope center of the total station at measurement point C from the slope distance BM3, vertical angle BM3, and elevation BM3. Observe the slope distance C of the center of the first reflecting prism at point P station from the total station at measurement point C.

[0031] Step 4: Based on the coordinates of measurement points A, B, and C, the "line-of-sight elevations" A, B, and C, and the slope distance of the center of the first reflecting prism at the point to be measured P as observed by the total station at measurement points A, B, and C, calculate the coordinates and elevation of the point to be measured P using the conventional method as follows:

[0032] According to the formula for calculating three-dimensional coordinates:

[0033]

[0034] In the formula:

[0035] x1, y1, and z1 are the coordinates and "line of sight elevation" of the known measurement point A;

[0036] x2, y2, and z2 are the coordinates and "line of sight elevation" of the known measurement point B;

[0037] x3, y3, and z3 are the coordinates and "line-of-sight elevation" of the known point C.

[0038] x, y, and z are the coordinates and elevation of the point P to be measured;

[0039] L1, L2, and L3 are the slope distances from the center of the total station telescope at measurement points A, B, and C to the center of the first reflecting prism at the point to be measured P, respectively.

[0040] Subtracting equation (1) from equation (2) and subtracting equation (1) from equation (3), we get:

[0041] (x2-x1)·x+(y2-y1)·y+(z2-z1)·z=-(A2-A1) / 2 (4)

[0042] (x3-x1)·x+(y3-y1)·y+(z3-z1)·z=-(A3-A1) / 2 (5)

[0043] in,

[0044] For ease of subsequent analysis, let:

[0045]

[0046] [i = 1, 2, 3]

[0047] [j = 1, 2, 3]

[0048] A il =-(A i -A1) / 2

[0049] [i = 2, 3]

[0050] Then equations (4) and (5) can be simplified to:

[0051] X 21 ·x+Y 21 ·y+Z 21 ·z=A 21

[0052] X 31 ·x+Y 31 ·y+Z 31 ·z=A 31

[0053] Solving for:

[0054]

[0055]

[0056] B0 = (A 21 ·Y 31 -A 31 ·Y 21 ) / D

[0057] B1 = (Y 21 ·Z 31 -Y 31 ·Z 21 ) / D

[0058] C0 = (A 31 ·X 21 -A 21 ·X 31 ) / D

[0059] C1=(X 31 ·Z 21 -X 21 ·Z 31 ) / D

[0060] Substituting equations (6) and (7) into equation (1), we get:

[0061] E·z 2 +2·F·z+G=0 (8)

[0062] in:

[0063]

[0064] F=B1·(B0-x1)+C1·(C0-y1)-z1,

[0065]

[0066] Solving equation (8) yields:

[0067]

[0068] Combining equations (6), (7), and (9), we can obtain:

[0069] X = B0 + B1·z

[0070] y = C0 + C1·z

[0071]

[0072] The actual elevation of point P is obtained by subtracting the height of the first centering rod from the obtained elevation z of point P.

[0073] The coordinates of the measurement points A, B, and C were obtained by measuring and adjusting using a total station using the angle measurement method. The error of the plane point position can be controlled within ±1mm.

[0074] The "line-of-sight elevation" error of the total station at each measurement point A, B, and C, calculated by observing the vertical angle and slant distance, is less than 0.1 mm, indicating high measurement accuracy. The error when using a steel tape measure is generally within 2 mm.

[0075] When the total station performs slope distance observation, the meteorological parameters such as temperature, air pressure, and humidity of the measurement points A, B, C and the point to be measured at the top of the tower P are input into each total station for automatic distance correction. The distance is then corrected by adding distance constants and multiplying constants to accurately obtain the optimal value of each observation slope distance.

[0076] The method of this invention is economical, adaptable, and highly accurate. It is suitable for measuring the reference cable of a suspension bridge across a canyon, the top elevation of the pylons of suspension bridges and cable-stayed bridges, the top elevation of buildings, or other environments where leveling or trigonometric leveling is not feasible. It has extremely high measurement accuracy and operability.

Claims

1. A method for calculating elevation using total station EDM distance measurement, characterized in that: include: A first centering rod with a first reflecting prism is installed at the point P to be measured. Three observation piers are buried in the ground around the building where the measurement point P is located. These piers serve as measurement points A, B, and C for setting up a total station to observe the building from point P. The three measurement points A, B, and C form a triangle that includes the building. Ground leveling points BM1, BM2, and BM3 are set up around each measurement point A, B, and C. The coordinates of the measurement points A, B, and C and the elevations of the leveling points BM1, BM2, and BM3 are measured. Follow these steps: Step 1: Set up a second centering rod with a second reflecting prism at a ground leveling point BM1 near measurement point A. Use the total station at measurement point A to observe the slope distance BM1 and vertical angle BM1 of the center of the second reflecting prism at ground leveling point BM1. Calculate the "line of sight elevation" A of the center of the total station telescope at measurement point A from the slope distance BM1, vertical angle BM1, and elevation BM1. Then, use the total station at measurement point A to observe the slope distance A of the center of the first reflecting prism at the point to be measured P. Step 2: Move the total station and the second centering rod to the observation pier of measurement point B and the ground leveling point BM2 near measurement point B, respectively. Keep the first centering rod of the point to be measured P station station stationary. Rotate the first reflecting prism to align with the total station of measurement point B. Observe the slope distance BM2 and vertical angle BM2 of the center of the second reflecting prism at the ground leveling point BM2 through the total station of measurement point B. Calculate the "line of sight elevation" B of the telescope center of the total station of measurement point B from the slope distance BM2, vertical angle BM2 and elevation BM2. Observe the slope distance B of the center of the first reflecting prism at the point to be measured P through the total station of measurement point B. Step 3: Move the total station and the second centering rod to the observation pier at measurement point C and the ground leveling point BM3 near measurement point C, respectively. Keep the first centering rod at point P station stationary. Rotate the first reflecting prism to align with the total station at measurement point C. Observe the slope distance BM3 and vertical angle BM3 of the center of the second reflecting prism at ground leveling point BM3 through the total station at measurement point C. Calculate the "line of sight elevation" C of the telescope center of the total station at measurement point C from the slope distance BM3, vertical angle BM3, and elevation BM3. Observe the slope distance C of the center of the first reflecting prism at point P station from the total station at measurement point C. Step 4: Based on the coordinates of measurement points A, B, and C, the "line of sight elevation" A, B, and C, and the slope distance of the center of the first reflecting prism at the point to be measured P observed by the total station at measurement points A, B, and C respectively, calculate the coordinates and elevation of the point to be measured P. Step 5: Subtract the height of the first centering rod from the obtained elevation of the point P to be measured to obtain the actual elevation of the point P to be measured.

2. The method for calculating elevation using total station EDM distance measurement according to claim 1, characterized in that: The test point P is made of stainless steel and has a hemispherical top surface.

3. The method for calculating elevation using total station EDM distance measurement according to claim 1, characterized in that: The measurement points A, B, and C are constructed using forced centering observation piers, with stainless steel centering plates for mounting the total station installed on the top of each of the three observation piers.

4. The method for calculating elevation using total station EDM distance measurement according to claim 1, characterized in that: The coordinates of the measurement points A, B, and C were obtained by measuring and adjusting using the total station's angle measurement method.

5. The method for calculating elevation using total station EDM distance measurement according to claim 1, characterized in that: When the total station performs slope distance observation, the meteorological parameters such as temperature, air pressure, and humidity of the measurement points A, B, C and the point to be measured at the top of the tower P are input into each total station for automatic distance correction. The distance is then corrected by adding distance constants and multiplying constants to accurately obtain the optimal value of each observation slope distance.

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