Surveying system, surveying method, and surveying program

Abstract

To provide a surveying system, a surveying method, and a surveying program capable of accurately measuring a measurement object.SOLUTION: A surveying system 1 comprises a reflector having a reflective surface and a surveying device 2 capable of measuring three-dimensional coordinates of a measurement object 15. The surveying device includes: a distance measuring unit that emits distance measuring light 11 and performs distance measurement based on reflected distance measuring light from the measurement object; an angle measuring unit that detects an emission direction of the distance measuring light; and a calculation control unit that controls operation of the distance measuring unit. The calculation control unit sets a normal line of the reflective surface, sets a distance in a normal direction to the reflective surface, measures a position in the normal direction of the measurement object relative to the reflective surface, and determines whether the measurement object is a real image or a virtual image reflected on the reflective surface on the basis of the measurement result of the measurement object.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a surveying system, a surveying method, and a surveying program that are capable of measuring the three-dimensional coordinates of a desired measurement point. [Background technology]

[0002] When surveying a desired measurement point at a construction site or the like, the survey is generally carried out using a measurement object having retroreflection, such as a prism. In prism surveying using a prism, for example, a pole with a prism attached is installed at a known position (measurement point), and the prism is leveled so that it is positioned vertically above the measurement point using a vial or the like, and then the prism is measured using a surveying device such as a total station.

[0003] Furthermore, when measuring multiple measurement points, the prism is tracked by the surveying instrument, and the prism is moved to each measurement point in sequence, and the prism is measured at each measurement point. At this time, in order for the surveying instrument to track the prism, it is first necessary to collimate the prism to the surveying instrument and have it recognize the prism. One method for collimating the prism is to have the surveying instrument search for the prism, automatically detect it, and collimate it.

[0004] However, if there is a reflective object such as a puddle at the construction site where the measurement point is located, the prism may be reflected on the water surface, and the surveying device may mistakenly detect the virtual image of the reflected prism as a prism. In this case, the surveying device may track and measure the virtual image, which may result in inaccurate measurements. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-125099 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-151423 [Patent Document 3] Japanese Patent Publication No. 2020-20747 [Patent Document 4] Japanese Patent Publication No. 2022-110635 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a surveying system, a surveying method, and a surveying program that are capable of accurately measuring an object to be measured. [Means for solving the problem]

[0007] The present invention relates to a surveying system having a reflecting object with a reflecting surface and a surveying instrument capable of measuring the three-dimensional coordinates of a measurement object, wherein the surveying instrument comprises a distance measuring unit that emits distance measuring light and measures distance based on the distance measuring light reflected from the measurement object, an angle measuring unit that detects the emission direction of the distance measuring light, and an arithmetic and control unit that controls the operation of the distance measuring unit, wherein the arithmetic and control unit sets a normal to the reflecting surface, sets a distance to the reflecting surface in the normal direction, measures the position of the measurement object in the normal direction relative to the reflecting surface, and, based on the measurement results of the measurement object, determines whether the measurement object is a real image or a virtual image reflected on the reflecting surface.

[0008] The present invention also relates to a surveying system in which the surveying instrument further comprises a horizontally rotatable surveying instrument main body, a telescope unit that is vertically rotatable relative to the surveying instrument main body and emits the distance measuring light, a detection unit that irradiates detection light having a predetermined detection range coaxially with the distance measuring light and detects the object to be measured based on reflected light from the object to be measured, a horizontal rotation drive unit that rotates the surveying instrument main body horizontally, and a vertical rotation drive unit that rotates the telescope unit vertically, and the arithmetic and control unit controls the operations of the distance measuring unit, the detection unit, the horizontal rotation drive unit, and the vertical rotation drive unit to irradiate the detection light, move the detection range along a predetermined path, detect the object to be measured based on the reflected light detected within the detection range during the movement, collimate and measure the detected object to be measured, and determine whether the object to be measured is a real image or a virtual image based on the position of the object to be measured in the normal direction to the reflecting surface.

[0009] The present invention also relates to a surveying system in which the surveying instrument further comprises a detection unit that irradiates detection light coaxially with the distance measurement light and detects the object to be measured based on the light reflected from the object to be measured, and an optical axis deflection unit that deflects the optical axes of the distance measurement light and the detection light, and the calculation control unit controls the operation of the distance measurement unit, the detection unit, and the optical axis deflection unit, scans the distance measurement light and the detection light via the optical axis deflection unit to obtain three-dimensional point cloud data of the object to be measured, and determines whether each point cloud data is a real image or a virtual image based on the position of the point cloud data in the normal direction to the reflection surface.

[0010] The present invention also relates to a surveying system in which the reflecting surface is a puddle with a horizontal water surface, the calculation control unit sets the height of the water surface, and based on the measurement results of the object to be measured, compares the height of the object to be measured with the height of the water surface, and judges the object to be measured that is determined to be higher than the water surface as a real image, and judges the object to be measured that is determined to be lower than the water surface as a virtual image.

[0011] The present invention also relates to a surveying system in which the calculation control unit is configured to continue moving the detection range along the predetermined path when the object to be measured is determined to be a virtual image.

[0012] The present invention also relates to a surveying system in which the detection unit also serves as a tracking unit, and the calculation control unit controls the horizontal rotation drive unit and the vertical rotation drive unit so that the reflected light from the object to be measured, which has been determined to be a real image, is positioned at the center of the detection range, thereby tracking the object to be measured.

[0013] The present invention also relates to a surveying system in which the calculation control unit sets a predetermined range centered on a virtual image of the object to be measured that is determined to be lower than the water surface as a mask range, and is configured so as not to perform measurements within the mask range.

[0014] The present invention also relates to a surveying system in which the calculation control unit is configured such that, when the measurement object is detected within the detection range, it moves the detection range a predetermined angle along a preset path, and if no new measurement object is detected, it judges the detected measurement object to be a real image, and if a new measurement object is detected, it judges the newly detected measurement object to be a real image, and judges the previously detected measurement object to be a virtual image, and discards the measurement results of the virtual image.

[0015] The present invention also relates to a surveying system in which the calculation control unit determines whether there is a measurement object that is symmetrical with respect to the water surface to the measurement object that has been determined to be a virtual image, and if such a symmetrical measurement object exists, it determines the measurement object that is lower than the water surface to be a virtual image, and if there is no symmetrical measurement object, it determines the measurement object that is lower than the water surface to be a real image, and discards the measurement results of the virtual image.

[0016] The present invention also relates to a surveying system configured such that the reflecting object has a reflecting surface provided at a position where the surveying instrument can aim, and the calculation control unit sets the distance in the normal direction between the surveying instrument and the reflecting surface, and based on the measurement results of the object to be measured, judges the object to be measured that is on the surveying instrument side of the boundary made by the reflecting surface to be a real image, and judges the object to be measured that is not on the surveying instrument side of the boundary made by the reflecting surface to be a virtual image.

[0017] The present invention also relates to a surveying system in which the calculation control unit is configured to identify the reflecting surface based on the amount of received light of the acquired measurement result.

[0018] The present invention also relates to a surveying system in which the surveying instrument further comprises a camera capable of acquiring images, and the calculation and control unit is configured to identify the reflective surface based on the images acquired by the camera.

[0019] The present invention also relates to a surveying system that is capable of switching between two measurement modes: a virtual image determination mode in which the calculation control unit determines, based on the measurement results of the measurement object, whether there is a measurement object whose position difference on the horizontal plane with the measurement object is less than a predetermined threshold, and if so, determines that the measurement object located below is a virtual image; and a reflective surface avoidance mode in which an area below the height of the measurement object determined to be a virtual image in the virtual image determination mode is set as a measurement avoidance area and measurement of the measurement avoidance area is not performed, and is configured to switch the measurement mode to the reflective surface avoidance mode when a virtual image is detected in the virtual image determination mode.

[0020] The present invention also relates to a surveying system in which the calculation control unit determines, based on the measurement results of the object to be measured, whether there is an object to be measured whose position difference on the horizontal plane with the object to be measured is less than a predetermined threshold, and if so, determines that the object to be measured located below is a virtual image, and sets a plane at a height midway between the virtual image and the real image corresponding to the virtual image as the reflecting surface.

[0021] The present invention also relates to a surveying method including the steps of: acquiring the normal of a predetermined reflecting surface by a surveying instrument; irradiating detection light so as to obtain a detection range of a predetermined size and moving the detection range along a predetermined path; detecting a measurement object based on reflected light detected within the detection range during the movement; collimating and measuring the detected measurement object; and determining whether the measurement object is a real image or a virtual image reflected on the reflection surface based on the position of the measurement object in the normal direction to the reflection surface.

[0022] Furthermore, the present invention relates to a surveying program that causes a surveying instrument to execute the following processes: a process of acquiring the normal of a predetermined reflecting surface; a process of irradiating detection light so as to obtain a detection range of a predetermined size and moving the detection range along a predetermined path; a process of detecting a measurement object based on reflected light detected within the detection range during the movement; a process of collimating and measuring the detected measurement object; and a process of determining whether the measurement object is a real image or a virtual image reflected on the reflecting surface based on the position of the measurement object in the normal direction to the reflecting surface. [Effects of the Invention]

[0023] According to the present invention, a surveying system is provided which has a reflecting object having a reflective surface and a surveying instrument capable of measuring the three-dimensional coordinates of a measured object, and the surveying instrument is equipped with a distance measuring unit which emits distance measuring light and measures distance based on the distance measuring light reflected from the measured object, an angle measuring unit which detects the emission direction of the distance measuring light, and an arithmetic control unit which controls the operation of the distance measuring unit, and the arithmetic control unit is configured to set a normal to the reflecting surface, set a distance to the reflecting surface in the normal direction, measure the position of the measured object in the normal direction relative to the reflecting surface, and based on the measurement results of the measured object, determine whether the measured object is a real image or a virtual image reflected on the reflecting surface, so that the measured object can be accurately measured without mistakenly detecting the virtual image of the measured object as a real image.

[0024] Furthermore, according to the present invention, the surveying instrument has the steps of acquiring the normal to a predetermined reflecting surface, irradiating detection light so as to obtain a detection range of a predetermined size and moving the detection range along a predetermined path, detecting the object to be measured based on the reflected light detected within the detection range during the movement, aiming and measuring the detected object to be measured, and determining whether the object to be measured is a real image or a virtual image reflected on the reflecting surface based on the position of the object to be measured in the normal direction to the reflecting surface, so that the virtual image of the object to be measured is not mistakenly detected as a real image, and the object to be measured can be measured accurately.

[0025] Furthermore, according to the present invention, the surveying instrument performs the following processes: acquiring the normal of a predetermined reflecting surface; irradiating detection light so as to obtain a detection range of a predetermined size and moving the detection range along a predetermined path; detecting the object to be measured based on the reflected light detected within the detection range during the movement; collimating and measuring the detected object to be measured; and determining whether the object to be measured is a real image or a virtual image reflected on the reflecting surface based on the position of the object to be measured in the normal direction to the reflecting surface. This provides the excellent effect of preventing the virtual image of the object to be measured from being mistaken for a real image and enabling accurate measurement of the object to be measured. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a perspective view of a surveying system according to a first embodiment. [Figure 2] 1 is a schematic configuration diagram of a surveying instrument according to a first embodiment. [Figure 3] FIG. 4 is an explanatory diagram illustrating a prism detection process according to the first embodiment. [Figure 4] 4 is a flowchart illustrating a prism detection process according to the first embodiment. [Figure 5] FIG. 10(A) is an explanatory diagram illustrating a prism detection process according to a second embodiment, and FIG. 10(B) is an explanatory diagram illustrating the relationship between a real image and a virtual image. [Figure 6]10 is a flowchart illustrating a prism detection process according to a second embodiment. [Figure 7] 10A and 10B are explanatory diagrams illustrating modifications of the first and second embodiments. [Figure 8] FIG. 10 is a perspective view of a surveying system according to a third embodiment. [Figure 9] FIG. 10 is an explanatory diagram illustrating a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0028] First, referring to FIG. 1, a surveying system according to a first embodiment of the present invention will be described.

[0029] The surveying system 1 has a surveying device 2 installed at a construction site, and a target device 3. The surveying device 2 is, for example, a total station with a tracking function, and is composed of a leveling unit 5 attached to a tripod 4, and a surveying device main body 6 attached to the leveling unit 5 and rotatable laterally relative to the leveling unit 5. The surveying device 2 is installed, for example, at a reference point having known three-dimensional coordinates.

[0030] The leveling unit 5 has a sensor (not shown) for detecting the inclination of the leveling unit 5 and a motor (not shown) for driving a leveling screw that levels the leveling unit 5, and is configured to automatically level the leveling unit 5 based on the detection results of the sensor.

[0031] The surveying instrument main body 6 has a telescope unit 7 that can rotate vertically relative to the surveying instrument main body 6. The telescope unit 7 also incorporates a distance measuring unit 8 (described later) and a tracking unit 9 (described later). The distance measuring unit 8 is configured to emit distance measuring light 11 on a distance measuring optical axis, and measure (measure) the distance to the object to be measured based on the distance measuring light reflected by the object to be measured. The tracking unit 9 is configured to emit tracking light 12 on a tracking optical axis, and perform tracking based on the reflected tracking light reflected by the object to be measured. The tracking optical axis is coaxial with the distance measuring optical axis, and the tracking light 12 is emitted coaxially with the distance measuring light 11.

[0032] The target device 3 has a rod-shaped pole 14 installed at the measurement point 13 and a prism 15 as a target (measurement object) attached to the upper end of the pole 14. The lower end of the pole 14 is conical, tapering downward and terminating in a sharp point. The prism 15 is, for example, a 360° full-circumference prism made up of a combination of multiple retroreflecting prisms, and has retroreflectivity. The center of the prism 15 is located on the axis of the pole 14, and the distance from the lower end of the pole 14 to the optical center of the prism 15 is known. The target device 3 also has a tilt detector such as a bubble tube (not shown), and the pole 14 can be positioned vertically based on the tilt detector.

[0033] 1, reference numeral 16 denotes a reflective object present at the construction site where the surveying device 2 is installed, for example, a puddle having a water surface that is a horizontal reflective surface. In this embodiment, as shown in FIG. 1, the measurement point 13 is present in the puddle 16, and the pole 14 and the prism 15 are installed in the puddle 16. At this time, when viewed from the installation position of the surveying device 2, the pole 14 and the prism 15 are reflected on the water surface of the puddle 16, i.e., the horizontal reflective surface, as a pole virtual image 17 and a prism virtual image 18.

[0034] Although the measurement point 13 is shown in the puddle 16 in FIG. 1, it may be located outside the puddle 16 as long as the prism virtual image 18 is reflected in the puddle 16 .

[0035] The axis of the pole 14 and the axis of the pole virtual image 17 coincide with each other, and each axis is continuous with the measurement point 13 as the center. The optical center of the prism virtual image 18 is located on the axis of the pole virtual image 17. That is, the positions of the prism 15 and the prism virtual image 18 are symmetrical with respect to the horizontal water surface of the puddle 16. Therefore, the three-dimensional coordinates of the prism 15 and the prism virtual image 18 are the same in terms of positions in the horizontal plane (XY coordinates), and only the height positions (Z coordinates) differ.

[0036] The distance from the measurement point 13 to the optical center of the prism 15 is the same as the distance from the measurement point 13 to the optical center of the prism virtual image 18. Therefore, when the height of the water surface of the puddle 16 is set to 0, the three-dimensional coordinates of the optical center of the prism 15 and the three-dimensional coordinates of the prism virtual image 18 are coordinates in which the signs of the heights (Z coordinates) are swapped.

[0037] When measuring the prism 15 with the surveying instrument 2, there is a case where the prism virtual image 18 is mistakenly detected as the prism 15 and measurement is performed. In this case, the distance measuring light 11 emitted from the surveying instrument 2 is reflected by the puddle 16 and then incident on the prism 15, and measurement is performed based on the distance measuring light 11 (reflected distance measuring light) reflected by the prism 15. However, since the prism virtual image 18 is located in the emission direction of the distance measuring light 11, i.e., on the emission optical axis, the obtained measurement result is the three-dimensional coordinates of the prism virtual image 18, not the three-dimensional coordinates of the prism 15.

[0038] Next, the configuration of the surveying instrument 2 will be described with reference to FIG.

[0039] The surveying instrument 2 has a horizontal rotation drive unit 19 for rotating the surveying instrument main body 6 horizontally relative to the leveling unit 5, a horizontal angle detector 21 for detecting the rotation angle (horizontal angle) of the surveying instrument main body 6, a vertical rotation drive unit 22 for rotating the telescope unit 7 vertically relative to the surveying instrument main body 6, and a vertical angle detector 23 for detecting the elevation angle (vertical angle) of the telescope unit 7. The surveying instrument 2 also has an arithmetic and control unit 24, a memory unit 25, a display unit 26, and an operation unit 27.

[0040] The horizontal rotation drive unit 19 and the vertical rotation drive unit 22 constitute the drive unit of the surveying instrument 2, and the horizontal angle detector 21 and the vertical angle detector 23 constitute the angle measurement unit for detecting the emission direction of the distance measuring light 11.

[0041] The distance measuring unit 8 performs distance measurement based on the time difference between the emission timing of the distance measuring light 11 and the reception timing of the reflected distance measuring light reflected by the object to be measured, and the speed of light, and calculates the distance to the object to be measured.

[0042] The tracking unit 9 emits the tracking light 12 on a tracking optical axis coaxial with the distance measurement optical axis and receives the reflected tracking light reflected from the object to be measured. The tracking unit 9 has a field of view (detection range) equivalent to the angle of view of the telescope unit 7, for example, about 1.5°, and is configured to track the object to be measured by driving the horizontal rotation drive unit 19 and the vertical rotation drive unit 22 so that, when the reflected tracking light is detected within the field of view, the receiving position of the reflected tracking light is positioned at the center of the field of view. In other words, the tracking unit 9 also functions as a reflected light detection unit that detects reflected light from the object to be measured, such as the prism 15, and the tracking light 12 also functions as detection light that detects the object to be measured.

[0043] The calculation control unit 24 may be a CPU specialized for this embodiment, or a general-purpose CPU, an embedded CPU, a microprocessor, etc. The storage unit 25 may be a semiconductor storage memory such as RAM, ROM, Flash ROM, or DRAM, a magnetic storage memory such as HDD, or an optical storage memory such as CD-ROM.

[0044] The storage unit 25 stores a sequence program for controlling the measurement operation (the distance measuring unit 8), a distance measuring program for calculating the distance by the distance measuring operation, an angle measuring program for calculating the irradiation direction (angle) of the distance measuring light 11 and the tracking light 12 based on the detection results of the horizontal angle detector 21 and the vertical angle detector 23, a measurement program for calculating the three-dimensional coordinates of the prism 15 based on the instrument height of the surveying device 2 and the distance from the bottom end of the pole 14 to the optical center of the prism 15, and Various programs are stored, such as a calculation program for calculating the original coordinates, a leveling program for causing the leveling unit 5 to perform leveling, a search program for automatically searching for and detecting the prism 15, a judgment program for judging whether the detected prism 15 is a real image or a virtual image, a tracking program for making the tracking unit 9 track the prism 15 that has been judged to be a real image, a drive control program for controlling the horizontal rotation drive unit 19, the vertical rotation drive unit 22, etc., and a display program for displaying measurement results, etc. on the display unit 26.

[0045] The storage unit 25 also stores data such as a path 28 (described later) of a detection range 29 for detecting the prism 15, a search range 31 (described later) indicating the range in which the detection process for the prism 15 is executed, measurement data (distance measurement data and angle measurement data) obtained when the prism 15 is measured, and three-dimensional coordinate data of the measurement point 13 calculated based on the measurement data. The calculation control unit 24 deploys and executes various programs stored in the storage unit 25 to perform various processes.

[0046] Next, a description will be given of measurement using the surveying system 1 with reference to the flowcharts of Figures 3 and 4. In the first embodiment, one target device 3 is used to measure one or more measurement points 13.

[0047] STEP 01 First, the surveying device 2 is installed at a reference point having known three-dimensional coordinates, and horizontal leveling is performed by the leveling unit 5. Also, the target device 3 is installed at the measurement point 13 in a vertical position.

[0048] STEP 02 Once the surveying device 2 is installed, the water surface height of the puddle 16 is then set. The height can be set, for example, by measuring the instrument height with a staff or the like and directly inputting it into the surveying device 2 via the operation unit 27, thereby obtaining and setting the water surface height relative to the machine center. Here, the water surface height is the height of the machine center below the machine center, and for example, the water surface height is set as Z0. Furthermore, since the water surface is a horizontal reflecting surface, the vertical direction can be considered the normal direction to the water surface, and the normal line can be considered to have been set automatically. Furthermore, the height is the vertical distance of the machine center of the surveying device 2 from the water surface, and can be considered the distance in the normal direction to the reflecting surface.

[0049] Alternatively, the water surface height Z0 can be set by various methods, such as by performing a non-prism survey of an arbitrary point on the installation surface of the surveying device 2 where the puddle 16 does not exist, and determining the height of the installation surface relative to the mechanical center of the surveying device 2, i.e., the height of the water surface. The target device 3 can be installed at an arbitrary point with the surveying device 2 tracking the prism 15, and the height of the installation surface can be calculated based on the measurement results of the prism 15.

[0050] STEP: 03 Once the water surface height Z0 is set, the detection process of the prism 15 is then started via the operation unit 27. That is, the calculation control unit 24 causes the tracking unit 9 to irradiate the tracking light 12, and also drives the horizontal rotation drive unit 19 and the vertical rotation drive unit 22 so that the detection range (field of view) 29 of the tracking unit 9 moves along a preset path 28.

[0051] 3, the path 28 is set so that the detection range 29 is moved vertically downward by a predetermined angle, moved horizontally to the right by a predetermined angle, further moved vertically upward by a predetermined angle, and moved horizontally to the right by a predetermined angle. These movements of the detection range 29 are repeated until the prism 15 is detected, that is, until the tracking light 12 reflected by the prism 15 (reflected tracking light) is detected. At this time, the paths 28 are set so that the detection ranges 29 of adjacent vertical paths 28 on the left and right overlap by a predetermined range.

[0052] The path 28 of the detection range 29 is not limited to the above path. For example, the path 28 may be set so that the detection ranges 29 of adjacent left and right paths 28 in the vertical direction overlap each other by a predetermined range, or the path 28 may be set so that the detection range 29 moves in a spiral shape. In other words, any path 28 may be used as long as the search range 31 set in advance in the prism detection process is searched without omission in the detection range 29.

[0053] STEP: 04 When the reflected light (reflected tracking light) of the tracking light 12 is detected by the prism 15 within the detection range 29, the arithmetic and control unit 24 drives the horizontal rotation drive unit 19 and the vertical rotation drive unit 22 so that the reflected tracking light is positioned at the center of the detection range 29. Since the detection range 29 is equivalent to the field of view of the telescope unit 7, when the reflected tracking light is positioned at the center of the detection range 29, the collimation of the prism 15 by the telescope unit 7 is also completed.

[0054] STEP 05 When the collimation of the prism 15 is completed, the calculation control unit 24 measures the distance and angle of the prism 15 and calculates the three-dimensional coordinates of the prism 15.

[0055] STEP 06: Once the three-dimensional coordinates of the prism 15 are measured, the calculation control unit 24 determines whether the height Z of the prism 15 is higher or lower than the water surface Z0 of the puddle 16. In other words, it determines the position in the normal direction of the reflecting surface.

[0056] As shown in FIG. 3, when it is determined that the height of the prism 15 is Z1 and is lower than the water surface Z0 (Z1 < Z0), the arithmetic control unit 24 determines that the detected prism 15 is the virtual image 18 of the prism, discards the measurement result of the virtual image 18 of the prism, and continues the detection process of the prism 15.

[0057] STEP:07 When it is determined that the height of the prism 15 detected in STEP:06 is Z2 and is higher than the water surface Z0 (Z2 > Z0), the arithmetic control unit 24 determines that the prism 15 is an actual prism (real image). The arithmetic control unit 24 calculates the three-dimensional coordinates of the measurement point 13 where the target device 3 is installed based on the three-dimensional coordinates of the prism 15 determined to be a real image and the distance from the optical center of the prism 15 to the lower end of the pole 14.

[0058] If there is no other measurement point 13 to be measured, the measurement process is terminated. If there is another measurement point 13 to be measured, the target device 3 is moved to the next measurement point 13, and the measurement of the measurement point 13 is executed. At this time, the reflected tracking light is detected within the detection range 29, and the horizontal rotation drive unit 19 and the vertical rotation drive unit 22 are driven so that the reflected tracking light is located at the center of the detection range 29. That is, since the tracking of the actual prism 15 is being executed, there is no need to perform the prism detection process again.

[0059] As described above, in the first embodiment, the height of the water surface of the water reservoir 16 is set, the prism 15 is searched for and detected, and when the prism 15 is detected, based on whether the height of the prism 15 is higher or lower than the water surface, it is determined whether the prism 15 is a real image or a virtual image.

[0060] Also, by discarding the measurement result of the prism 15 determined to be a virtual image and continuing the detection process of the prism 15 until the prism 15 determined to be a real image is detected, it is possible to track and measure only the prism 15.

[0061] Therefore, even if a reflective object such as the puddle 16 exists at the construction site and the prism virtual image 18 is reflected in the puddle 16, the surveying device 2 will not erroneously detect the prism virtual image 18 as the prism 15.

[0062] Furthermore, since the prism virtual image 18 is not erroneously detected as the prism 15, the real image of the prism 15 can be accurately collimated, and the prism 15 can be accurately tracked and measured.

[0063] Furthermore, in a process in which the number of measurement points 13 and the number of measurements are preset, the number of measurements is consumed by measuring the prism virtual image 18, and there is a risk that the actual prism 15 will not be measured. On the other hand, in this embodiment, the measurement results of the prism virtual image 18 are discarded, so that it is possible to prevent the prism 15 from being overlooked in measurement.

[0064] In the first embodiment, only the reflected tracking light detected at a position lower than the water surface is determined to be the prism virtual image 18. However, when reflected tracking light is detected at a position lower than the water surface, the detection range 29 may be moved vertically upward by a predetermined angle, and whether the image is a real image or a virtual image may be determined based on whether new reflected tracking light is detected. The angle for detecting reflected tracking light at a position symmetrical with respect to the water surface in the detection range 29 is determined by the horizontal distance to the prism 15 and the vertical distance from the horizontal to the prism 15. Therefore, the three-dimensional coordinates (x, y, z) of the prism 15 detected at a position lower than the water surface are obtained, and the horizontal distance to the prism 15 and the vertical distance between the prism 15 and the water surface are calculated based on the three-dimensional coordinates. The angle at which the detection range 29 is moved upward by a distance twice the calculated vertical distance can be determined as the angle for detecting reflected tracking light. That is, the detection range 29 can be moved a predetermined angle to the end of a preset path.

[0065] Furthermore, since the real image and virtual image exist in positions symmetrical with respect to the water surface, and a real image always exists vertically above a real image, if no new reflected tracking light is detected vertically above the detection position of the reflected tracking light, it can be determined that the detected reflected tracking light is a real image. Furthermore, if new reflected tracking light is detected vertically above the detection position, it can be determined that the previously detected reflected tracking light is a virtual image, and the newly detected reflected tracking light is a real image. In this case, the water surface setting can be omitted.

[0066] In the first embodiment, the prism detection process is performed after the surveying instrument 2 is leveled by the leveling unit 5, but the leveling unit 5 is not necessarily required. For example, if the surveying instrument 2 has an inclination detector such as a tilt sensor or the inclination detector disclosed in Patent Document 2, the inclination of the surveying instrument 2 can be detected in real time.

[0067] Therefore, by cooperating the horizontal rotation drive unit 19 and the vertical rotation drive unit 22 based on the detection results, it is possible to horizontally rotate the surveying instrument main body 6 and vertically rotate the telescope unit 7, and also to correct the measurement results. In this case, the leveling unit 5 can be omitted.

[0068] Next, a second embodiment of the present invention will be described with reference to Figures 2, 5(A), and 5(B). In Figure 5(A), the same components as those in Figure 3 are designated by the same reference numerals, and their description will be omitted.

[0069] In the second embodiment, a configuration is adopted in which a plurality of target devices 3 (see FIG. 1) are used to calculate three-dimensional coordinates of a plurality of measurement points 13 (see FIG. 1).

[0070] Furthermore, in the prism detection process of the second embodiment, when a prism 15 is detected, that is, when the tracking light 12 (reflected tracking light) reflected by the prism 15 is detected within the detection range 29, a decision is not made as to whether to stop or continue the detection process. That is, in the second embodiment, a path 28 is set so that the entire search range 31 is searched, and the prism detection process is continued until the search of the entire search range 31 is completed.

[0071] For example, in the second embodiment, the path 28 is set in a spiral shape from the center to the periphery of the search range 31. Specifically, as shown in Fig. 5(A), the path 28 is set so that the detection range 29 moves vertically upward, horizontally to the right, vertically downward, and horizontally to the left from the center in that order, and the detection ranges 29 of adjacent paths 28 overlap each other by a predetermined amount.

[0072] At this time, in the process of moving the detection range 29, the same prism 15 may be detected multiple times at different positions in the detection range 29. In particular, when the virtual image of the prism 15 (prism virtual image 18) is detected multiple times, the prism virtual image 18 is collimated and measured each time it is detected, and the measurement results are discarded, which increases the processing time.

[0073] Therefore, in the second embodiment, when it is determined that the detected prism 15 is the prism virtual image 18, a mask range 32 is set in a predetermined range centered on the optical center of the prism virtual image 18, and measurement of the prism 15 detected within the mask range 32 is not performed. The mask range 32 is, for example, equal to or approximately equal to the field of view of the telescope unit 7.

[0074] In the above, the prism 15 detected within the mask range 32 is not measured, but it may be configured to ignore the reflected tracking light within the mask range 32. Furthermore, after the entire search of the search range 31 is completed, the created mask range 32 may be used for another search, etc.

[0075] The measurement process in the second embodiment will be described below with reference to the flowchart in Fig. 6. Note that a description of the same steps as those in the flowchart in Fig. 4 will be omitted.

[0076] STEP: 11 to STEP: 13 As in the first embodiment, the surveying device 2 is installed at a reference point having known three-dimensional coordinates, and the height of the water surface of the puddle 16 is set, after which the calculation control unit 24 is made to start the prism detection process.

[0077] When performing the detection process of the prism 15, the calculation control unit 24 drives the horizontal rotation drive unit 19 and the vertical rotation drive unit 22 to rotate the telescope unit 7 in the horizontal and vertical directions so that the detection range 29 moves along the preset path 28. In addition, in parallel with the movement of the detection range 29, the tracking unit 9 emits the tracking light 12.

[0078] STEP 14: While the detection range 29 is moving, it is constantly determined whether or not the search of the entire search range 31 has been completed, and the process continues until it is determined that the search is completed. When the search is completed and it is determined that the measurement of all the prisms 15 and the measurement points 13 within the search range 31 has been completed, the measurement process ends.

[0079] STEP 15, STEP 16 During the prism detection process, when the reflected tracking light is detected as the prism 15 within the detection range 29, the calculation control unit 24 determines whether the position where the reflected tracking light is detected is within the mask range 32. If it is determined to be within the mask range 32, the measurement of the prism 15 is not performed, and the search continues.

[0080] STEP: 17, STEP: 18 If the detected reflected tracking light (the prism 15) is determined to be outside the mask range 32, the calculation control unit 24 collimates and measures the prism 15, and determines whether it is higher than the water surface of the puddle 16 based on the measurement results.

[0081] STEP 19: If it is determined that the position of the prism 15 is lower than the water surface, it is determined that the prism 15 is the prism virtual image 18, and the mask range 32 is set to be centered on the prism virtual image 18.

[0082] STEP 20: If it is determined that the position of the prism 15 is higher than the water surface, it is determined that the prism 15 is a real image, and the three-dimensional coordinates of the measurement point 13 are calculated based on the measurement result of the prism 15.

[0083] The processing of STEP: 14 to STEP: 20 continues until the entire search range 31 has been searched with the detection range 29, and the measurement processing is completed.

[0084] In the second embodiment, the calculation control unit 24 sets a predetermined range centered on the prism 15, i.e., the prism virtual image 18, that is determined to be lower than the water surface height of the puddle 16 as a mask range 32, and is configured to consider the prism 15 detected within the mask range 32 to be the prism virtual image 18, and not perform collimation or measurement.

[0085] Therefore, it is not necessary to detect the same prism virtual image 18 multiple times, perform collimation and distance measurement each time, and determine whether it is a real image or a virtual image, thereby reducing work time and improving workability.

[0086] In the second embodiment, whether an image is real or virtual is determined based on the height of the prism 15 relative to the water surface of the puddle 16. On the other hand, since real and virtual images are symmetrical with respect to the water surface, if there are two measurement results that are the same in position on the horizontal plane but differ only in height, the two measurement results may be compared and the higher one may be determined to be a real image and the lower one a virtual image.

[0087] In the first and second embodiments, a total station is used as the surveying instrument 2, but even if other surveying instruments are used, as in the following modified examples, it is possible to distinguish between real and virtual images according to the present invention.

[0088] For example, Fig. 7(A) shows a laser scanner capable of acquiring 360° full-circle point cloud data as shown in Patent Document 3. This laser scanner can be used as the surveying device 2. Note that in Fig. 7(A), a part of the point cloud data 33 in which three-dimensional coordinates are measured for each point is shown.

[0089] Even when using a laser scanner, similar to the first and second embodiments, by setting the height Z0 of the water surface of the puddle 16, the measurement results determined to be lower than the water surface (Z1 < Z0) can be discarded as the measurement results of the virtual image point cloud data 30 of the virtual image reflected in the puddle 16. As a result, only the measurement results of the real image at a position higher than the water surface (Z2 > Z0) can be obtained, and accurate three-dimensional point cloud data 33 can be obtained.

[0090] Also, Fig. 7(B) shows a laser scanner configured with an optical axis deflection unit composed of two disk prisms as shown in Patent Document 4, which deflects the optical axes of the distance measurement light 11 and the tracking light 12 two-dimensionally and enables scanning (raster scan) of the distance measurement light 11. By using this laser scanner, not only the acquisition of the point cloud data 33 but also the detection and tracking of the prism 15 can be performed.

[0091] In the case of the above laser scanner as well, by setting the height Z0 of the water surface and discarding the prism 15 detected at a position lower than the water surface or the measurement results at a position lower than the water surface as the virtual image point cloud data 30 and adopting only the measurement results of the real image higher than the water surface, accurate detection of the prism 15 and acquisition of the point cloud data 33 can be performed.

[0092] Also, in the first embodiment, the second embodiment, and their modified examples, all measurement results lower than the water surface are determined to be measurement results of virtual images based on the height of the water surface. On the other hand, as shown in Fig. 5(B), the real image and the virtual image have the same position (XY coordinates) in the horizontal plane and the same distance from the water surface. That is, the real image and the virtual image exist at symmetric positions with respect to the water surface. Furthermore, when a virtual image exists, a real image corresponding to the virtual image always exists.

[0093] Therefore, in addition to determining whether the measurement result of the prism 15 or the point cloud data 33 is lower than the water surface, the calculation control unit 24 may also determine, for a measurement result determined to be lower than the water surface, whether a measurement result exists at a position symmetrical with respect to the water surface, i.e., whether a real image exists, and may determine that the measurement result is a virtual image only if a corresponding real image exists.

[0094] As a result, even if the object to be measured is located lower than the water surface, such as when measuring the bottom of the puddle 16, it will not be judged as a virtual image. Therefore, it becomes possible to measure a real image located lower than the water surface, improving the versatility of the processing.

[0095] Although the above description has been given of the case where the positions (X and Y coordinates) of the real image and virtual image in the horizontal plane match, it is also possible to set a threshold in advance in the X and Y directions, and determine whether a measurement result below the water surface is a virtual image based on whether there is a measurement result where the distance to the water surface is the same as that of the measurement result below the water surface and the difference in position in the X and Y directions is less than the threshold. For example, if the threshold is about 5 mm, it is possible to distinguish a virtual image.

[0096] By setting thresholds in the X and Y directions, it is possible to determine that measurement results that do not completely match the horizontal position of measurement results below the water surface correspond to the measurement results, so that virtual images can be detected even if the water surface is rippling due to wind, for example.

[0097] Next, a third embodiment of the present invention will be described with reference to Fig. 8. In Fig. 8, the same components as those in Fig. 7(A) are given the same reference numerals, and their description will be omitted.

[0098] In the first embodiment, the second embodiment, and their modifications, the discrimination of a virtual image caused by a puddle 16 (see FIG. 1) existing on the construction surface of a construction site has been described. On the other hand, if a reflective surface that reflects the ranging light 11 and the tracking light 12 can be set, even if the reflective surface is not a water surface, the virtual image can be discriminated by processing substantially the same as that for a water surface.

[0099] 8, reference numeral 34 denotes a window as an example of a reflecting object provided with a reflecting surface. The window 34 has a predetermined reflectance and is configured to reflect the distance measuring light 11 and the tracking light 12.

[0100] In the third embodiment, for example, a laser scanner is used as the surveying device 2. The window 34 and parts other than the window 34, such as a wall surface 35, have different reflectances. Therefore, when point cloud data 33 including the window 34 is acquired, the window 34 and the wall surface 35 can be distinguished based on the amount of reflected distance measuring light received by the surveying device 2.

[0101] Once the window 34 is identified, the calculation control unit 24 (see FIG. 2) calculates the inclination of the window 34 (the inclination of the reflecting surface) based on the measurement results around the outline of the window 34, and also calculates a normal 36 of the window 34 and sets the normal 36. The direction of the normal 36 corresponds to the vertical direction in the virtual image discrimination of the water surface.

[0102] Furthermore, the calculation control unit 24 calculates the distance to the window 34 in the direction of the normal line 36 based on, for example, the measurement results of the wall surface 35 other than the window 34 and the normal line 36, and sets the distance and also sets the position of the window 34. Once the position of the window 34 has been set, the calculation control unit 24 causes the surveying instrument 2 to perform a scan. Note that the distance H in the normal line direction to the window 34 corresponds to the height of the water surface in the virtual image discrimination of the water surface.

[0103] When a scan is performed, point cloud data 33 that is closer to the surveying instrument 2 than the window 34 and point cloud data 33 that is farther from the surveying instrument 2 than the window 34 are acquired, with the direction of the normal line 36 as the reference. That is, with respect to the boundary surface formed by the reflective surface of the window 34, point cloud data 33 (measurement object) that is on the surveying instrument 2 side and point cloud data 33 (measurement object) that is not on the surveying instrument 2 side are acquired. The calculation control unit 24 discards the point cloud data 33 that is farther from the surveying instrument 2 than the window 34 as the measurement result of virtual image point cloud data 30, and can acquire only the point cloud data 33 that is closer to the surveying instrument 2 than the window 34 as a real image.

[0104] Therefore, since the measurement results of the virtual image are not mixed into the acquired point cloud data 33, it is possible to acquire highly reliable and highly accurate point cloud data 33.

[0105] In the third embodiment, the case where the surveying instrument 2 is a laser scanner has been described, but virtual images can also be discriminated in the same way when a total station is used.

[0106] Furthermore, for the point cloud data 33 that has been determined to be virtual image point cloud data 30, it may be determined whether a real image symmetrical with respect to the window 34 exists. This makes it possible to obtain measurement results for the object to be measured that is beyond the window 34.

[0107] In the third embodiment, the position of the window 34 is determined based on the point cloud data 33 of the window 34 and the wall surface 35, but the determination method is not limited to this. For example, a camera may be provided in the surveying device 2, and the position of the window 34 may be determined based on an image acquired by the camera.

[0108] Furthermore, in the first and second embodiments, a puddle 16 having a water surface is exemplified as a reflective object having a reflective surface, and in the third embodiment, the window 34 provided on the wall surface 35 is exemplified, but reflective objects having a reflective surface are not limited to these. For example, the window 34 may be located not only on the wall surface 35 but also on the ceiling or floor. Furthermore, the reflective object may be a mirror or signboard installed on the edge surface of a building such as a wall surface or at a position other than the edge surface, and may be inclined at any angle relative to the horizontal. In other words, any reflective object may be used as long as it is located at a position that can be collimated by the surveying instrument 2 and has a reflective surface that can reflect the distance measuring light 11 and the tracking light 12.

[0109] Furthermore, if there is a BIM (Building Information Modeling) of the construction site, the window 34 may be determined based on the BIM data. By using BIM, it is also possible to check whether the construction is being carried out correctly.

[0110] In the first to third embodiments, the object to be measured is exemplified by a target, for example, a prism 15, attached to a pole 14. However, it goes without saying that the object to be measured may be a reflective object such as a retroreflective sheet or a printed target, and the reflective object may be directly placed at the measurement point 13.

[0111] Furthermore, in the first to third embodiments, the surveying device 2 is installed at a construction site having reflecting objects, but the surveying device 2 may be installed at a location other than a construction site. For example, the surveying device 2 may be installed at a site where no construction work is being carried out, and the surveying device 2 may be used to check the site.

[0112] Next, a fourth embodiment of the present invention will be described with reference to Fig. 9. In Fig. 9, the same components as those in Fig. 6 are given the same reference numerals, and their description will be omitted.

[0113] In the fourth embodiment, the surveying instrument 2 can measure the object to be measured in two measurement modes: a virtual image determination mode and a reflective surface avoidance mode. The calculation control unit 24 (see FIG. 2) can perform prism detection processing based on each measurement mode and can automatically switch between each measurement mode.

[0114] As in the second embodiment, the virtual image determination mode is a measurement mode in which a path 28 (see FIG. 5) is set so that the entire search range 31 (see FIG. 5) is searched, and the prism detection process continues until the search of the entire search range 31 is completed. In addition, in the virtual image determination mode, the calculation control unit 24 detects the reflected tracking light, and when collimating and measuring the prism 15, which is the measurement object, determines whether or not there is a measurement result in which the difference in position in the X and Y directions is equal to or less than a predetermined threshold on the horizontal X and Y plane.

[0115] If there is a measurement result that is equal to or less than the predetermined threshold, the calculation control unit 24 determines that the lower of the two measurement results is the measurement result of the prism virtual image 18. In addition, the calculation control unit 24 switches the measurement mode from the virtual image determination mode to the reflective surface avoidance mode.

[0116] In the reflective surface avoidance mode, a measurement avoidance area is set based on the measurement result. For example, based on the measurement result in which the prism virtual image 18 is determined to be the prism virtual image 18 in the virtual image determination mode, the arithmetic and control unit 24 sets an area below the height (Z1) of the prism virtual image 18 as a measurement avoidance area 37. In addition, the arithmetic and control unit 24 executes a prism detection process so as not to perform collimation and measurement in the measurement avoidance area 37. Alternatively, the arithmetic and control unit 24 reduces the search range 31 and changes the path 28 so that the measurement avoidance area 37 is not included in a detection range 29 (see FIG. 5) that moves along the path 28.

[0117] In the reflective surface avoidance mode, the prism detection process continues even after the measurement avoidance area 37 is set, and when the calculation control unit 24 determines that the newly detected measurement object is the prism virtual image 18, it determines whether the prism virtual image 18 is located higher than the measurement avoidance area 37. When it is determined that the prism virtual image 18 is located higher than the measurement avoidance area 37, it sets an area below the newly detected prism virtual image 18 as the new measurement avoidance area 37 and resumes the prism detection process. When it is determined that the prism virtual image 18 is located lower than the measurement avoidance area 37, it continues the prism detection process without newly setting the measurement avoidance area 37.

[0118] In the fourth embodiment, the surveying instrument 2 can automatically switch between two measurement modes, a virtual image determination mode and a reflective surface avoidance mode, and when it is determined based on the measurement result that the object is the prism virtual image 18, the measurement mode is automatically changed to the reflective surface avoidance mode. In addition, in the reflective surface avoidance mode, the measurement object detected within the measurement avoidance area 37 is determined to be the prism virtual image 18, and collimation and measurement are not performed.

[0119] Therefore, every time the prism virtual image 18 is detected within the measurement avoidance area 37, it is not necessary to perform collimation and measurement and determine whether it is a real image or a virtual image, thereby reducing the working time.

[0120] Furthermore, when the measurement avoidance area 37 is set, if the search range 31 and the path 28 are re-set so that the measurement avoidance area 37 is not included in the detection range 29, the search range 31 becomes narrower and the path 28 becomes shorter, thereby shortening the processing time for the prism detection process and enabling the reduction of work time.

[0121] In the fourth embodiment, based on the measurement result determined to be the prism virtual image 18, the area below the prism virtual image 18 is set as the measurement avoidance area 37. On the other hand, based on the measurement result determined to be the prism virtual image 18 and the measurement result of the real image of the prism 15 corresponding to the prism virtual image 18, a plane located at an intermediate height (Z0) between the prism 15 and the prism virtual image 18 may be automatically set as the water surface (reflecting surface), and the area below the water surface may be set as the measurement avoidance area 37. The automatic setting process of the water surface height can also be applied to the first and second embodiments.

[0122] Furthermore, in the fourth embodiment, the puddle 16 is the reflective object, and the water surface is the reflective surface. However, it goes without saying that the above-described automatic switching of measurement modes and automatic setting of the reflective surface can be applied to any reflective object other than the water surface, such as the window 34 in the third embodiment (see FIG. 8), as long as it has a reflective surface.

[0123] For example, the automatic setting of the water surface height is the automatic setting of the normal distance to the window 34, and the measurement avoidance area 37 is the area on the opposite side of the surveying device 2 as a plane (reflecting surface) reference passing through the measurement results (three-dimensional coordinates) that are determined to be virtual images. [Explanation of symbols]

[0124] 1. Surveying System 2 Surveying equipment 6 Surveying device body 8 Ranging section 9 Tracking part 11 Ranging light 12 Tracking light 15 Prism 16 Puddle 18 Prism Virtual Image 24 Calculation control unit 28 routes 29 Detection Range 31 Search Range 32 Mask range

Claims

1. A surveying system having a reflecting object with a reflective surface and a surveying instrument capable of measuring the three-dimensional coordinates of a measurement object, wherein the surveying instrument is equipped with a distance measuring unit that emits distance measuring light and measures distance based on the distance measuring light reflected from the measurement object, an angle measuring unit that detects the emission direction of the distance measuring light, and an arithmetic and control unit that controls the operation of the distance measuring unit, wherein the arithmetic and control unit sets a normal to the reflecting surface, sets a distance to the reflecting surface in the normal direction, measures the position of the measurement object in the normal direction relative to the reflecting surface, and determines whether the measurement object is a real image or a virtual image reflected on the reflecting surface based on the measurement results of the measurement object.

2. 2. The surveying system according to claim 1, wherein the surveying instrument further comprises: a surveying instrument main body that can rotate horizontally; a telescope unit that can rotate vertically relative to the surveying instrument main body and that emits the distance measuring light; a detection unit that irradiates detection light having a detection range that is coaxial with the distance measuring light and that detects the object to be measured based on reflected light from the object to be measured; a horizontal rotation drive unit that rotates the surveying instrument main body horizontally; and a vertical rotation drive unit that rotates the telescope unit vertically, wherein the arithmetic and control unit is configured to control the operations of the distance measuring unit, the detection unit, the horizontal rotation drive unit, and the vertical rotation drive unit to irradiate the detection light, move the detection range along a predetermined path, detect the object to be measured based on the reflected light detected within the detection range during the movement, collimate and measure the detected object to be measured, and determine whether the object to be measured is a real image or a virtual image based on the position of the object to be measured in the normal direction to the reflecting surface.

3. The surveying system of claim 1, wherein the surveying device further comprises a detection unit that irradiates detection light coaxially with the distance measurement light and detects the object to be measured based on reflected light from the object to be measured, and an optical axis deflection unit that deflects the optical axes of the distance measurement light and the detection light, and the calculation control unit controls the operation of the distance measurement unit, the detection unit, and the optical axis deflection unit, scans the distance measurement light and the detection light via the optical axis deflection unit to obtain three-dimensional point cloud data of the object to be measured, and determines whether each point cloud data is a real image or a virtual image based on the position of the point cloud data in the normal direction to the reflection surface.

4. 4. The surveying system according to claim 2 or claim 3, wherein the reflecting surface is a puddle having a horizontal water surface, and the calculation control unit is configured to set the height of the water surface, compare the height of the measurement object with the height of the water surface based on the measurement results of the measurement object, and judge the measurement object determined to be higher than the water surface to be a real image, and judge the measurement object determined to be lower than the water surface to be a virtual image.

5. The surveying system according to claim 2 , wherein the calculation control unit is configured to continue moving the detection range along the preset path when the object to be measured is determined to be a virtual image.

6. The surveying system according to claim 2, wherein the detection unit also serves as a tracking unit, and the calculation control unit is configured to control the horizontal rotation drive unit and the vertical rotation drive unit so that the reflected light from the measurement object, which has been determined to be a real image, is positioned at the center of the detection range, thereby tracking the measurement object.

7. The surveying system according to claim 4, wherein the calculation control unit is configured to set a predetermined range centered on a virtual image of the object to be measured that is determined to be lower than the water surface as a mask range, and not perform measurements within the mask range.

8. The surveying system according to claim 2, wherein the calculation control unit is configured to, when the measurement object is detected within the detection range, move the detection range a predetermined angle along a preset path, and if no new measurement object is detected, judge the detected measurement object to be a real image, and if a new measurement object is detected, judge the newly detected measurement object to be a real image, and judge the previously detected measurement object to be a virtual image, and discard the measurement results of the virtual image.

9. The surveying system according to claim 4, wherein the calculation control unit is configured to determine whether there is a measurement object that is symmetrical with respect to the water surface to the measurement object that has been determined to be a virtual image, and if such a symmetrical measurement object exists, to determine that the measurement object that is lower than the water surface is a virtual image, and if such a symmetrical measurement object does not exist, to determine that the measurement object that is lower than the water surface is a real image, and to discard the measurement results of the virtual image.

10. 4. The surveying system according to claim 2 or 3, wherein the reflecting object has the reflecting surface provided at a position where the surveying instrument can aim at it, and the calculation control unit is configured to set a distance in the normal direction between the surveying instrument and the reflecting surface, and to determine, based on the measurement results of the measured object, the measured object that is on the surveying instrument side of the boundary formed by the reflecting surface as a real image, and to determine the measured object that is not on the surveying instrument side of the boundary formed by the reflecting surface as a virtual image.

11. The surveying system according to claim 10, wherein the calculation control unit is configured to identify the reflecting surface based on the amount of received light of the acquired measurement result.

12. The surveying system according to claim 10, wherein the surveying instrument further comprises a camera capable of acquiring an image, and the arithmetic and control unit is configured to identify the reflective surface based on the image acquired by the camera.

13. The calculation control unit is capable of switching between two measurement modes: a virtual image determination mode configured to determine, based on the measurement results of the measurement object, whether there is a measurement object whose position difference on a horizontal plane with the measurement object is less than a predetermined threshold, and if so, to determine that the measurement object located below is a virtual image; and a reflective surface avoidance mode configured to set a measurement avoidance area below the height of the measurement object determined to be a virtual image in the virtual image determination mode and not measure the measurement avoidance area, and is configured to switch the measurement mode to the reflective surface avoidance mode when a virtual image is detected in the virtual image determination mode.

14. The surveying system according to claim 2 or claim 3, wherein the calculation control unit is configured to determine, based on the measurement results of the measurement object, whether there is a measurement object whose position difference on a horizontal plane with the measurement object is less than a predetermined threshold, and if there is, to determine that the measurement object located below is a virtual image, and to set a plane at a height intermediate between the virtual image and the real image corresponding to the virtual image as the reflecting surface.

15. A surveying method comprising the steps of: acquiring the normal of a predetermined reflecting surface using a surveying instrument; irradiating detection light so as to obtain a detection range of a predetermined size and moving the detection range along a predetermined path; detecting a measurement object based on reflected light detected within the detection range during the movement; collimating and measuring the detected measurement object; and determining whether the measurement object is a real image or a virtual image reflected on the reflecting surface based on the position of the measurement object in the normal direction to the reflecting surface.

16. A surveying program that causes a surveying device to execute the following processes: a process of acquiring the normal of a predetermined reflecting surface; a process of irradiating detection light so as to obtain a detection range of a predetermined size and moving the detection range along a predetermined path; a process of detecting a measurement object based on reflected light detected within the detection range during the movement; a process of collimating and measuring the detected measurement object; and a process of determining whether the measurement object is a real image or a virtual image reflected on the reflecting surface based on the position of the measurement object in the normal direction to the reflecting surface.

Images