Reflector, surveying system, and control point surveying method

Abstract

The present invention provides a reflector, a surveying system, and a control point surveying method that enable detection of the direction of incidence of light rays to the reflector, regardless of the direction of incidence of the light rays. [Solution] The prism section 2 comprises a prism that constitutes a wide-angle prism by a plurality of prisms 4 arranged in at least a part of the circumferential direction, and a direction angle detector 3 is positioned such that the principal optical axis passes through a reference point 1a located in a space 5 formed within the prism section. The prism is configured such that a portion of the incident light ray 12 enters the prism section and the remainder enters the direction angle detector. The direction angle detector includes a deflection optical member 6 that deflects the light ray, an imaging lens 8, and a light receiving sensor 11. The light ray deflected by the deflection optical member enters the imaging lens, is imaged by the imaging lens and projected onto the light receiving sensor, and is configured to output position information including the angle of incidence of the light ray to the deflection optical member based on the light receiving position of the light receiving sensor.

Description

Technical Field

[0001] The present invention relates to a reflector that retroreflects a light beam such as a laser beam, a surveying system, and a reference point surveying method.

Background Art

[0002] In laser surveying, a reflector that retroreflects the distance measuring light is used as a measurement target. The reflector is provided on a pole that indicates the measurement point. Usually, as the reflector, an all-round prism that retroreflects a wide range of laser beams is used.

[0003] The all-round prism is composed of a combination of a plurality of corner cube prisms, has a complicated structure, and the retroreflecting point (measurement reference point) may be slightly displaced corresponding to the incident direction of the light beam, which has been a factor causing measurement errors in distance, vertical angle, and horizontal angle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention provides a reflector, a surveying system, and a reference point surveying method capable of detecting the incident direction of a light beam to the reflector regardless of the incident direction of the light beam.

Means for Solving the Problems

[0006] The present invention relates to a reflector comprising a prism section comprising a plurality of prisms arranged in at least a portion of the circumferential direction to constitute a wide-angle prism, and a direction angle detector positioned such that the principal optical axis passes through a reference point located in a space formed within the prism section, wherein a portion of the incident light ray enters the prism section and the remainder enters the direction angle detector, the direction angle detector comprising a deflection optical member for deflecting the light ray, an imaging lens, and a light receiving sensor, wherein the light ray deflected by the deflection optical member enters the imaging lens, is imaged by the imaging lens on the light receiving sensor, and outputs position information including the angle of incidence of the light ray to the deflection optical member based on the light receiving position of the light receiving sensor.

[0007] Furthermore, the present invention relates to a reflector configured such that the light rays incident on the deflecting optical member are received within a specific region on the light receiving sensor corresponding to the angle of incidence to the deflecting optical member.

[0008] Furthermore, the present invention relates to a reflector, which is a lens that internally reflects the light rays incident from the side multiple times as a deflecting optical member.

[0009] Furthermore, the present invention relates to a reflector in which the deflection optical member is a fisheye lens with a field of view of 180° or more.

[0010] Furthermore, the present invention relates to a reflector in which the deflection optical member is a deflection prism having a reflective surface that internally reflects the light rays incident from the incident surface, and the reflective surface is an axisymmetric free-form surface.

[0011] Furthermore, the present invention relates to a reflector configured such that the prisms are alternately arranged in upper or lower sections with different corner vertices.

[0012] Furthermore, the present invention relates to a reflector in which the prism is a square pyramidal prism with a trapezoidal base, and the prism portion is configured such that the prisms are arranged alternately in the circumferential direction while their lower bases are inverted vertically.

[0013] Furthermore, the present invention relates to a reflector in which the prism is a generally conical prism having a circular base and three inclined surfaces, and the prism section is configured such that each prism is arranged in a state where it is rotated around its axis relative to adjacent prisms.

[0014] The present invention also relates to a surveying system comprising a target device provided with the above-mentioned reflector and a surveying device capable of measuring the reflector, wherein the target device has a communication unit for transmitting light reception position information emitted by the light receiving sensor to the surveying device, the surveying device has pre-existing table data relating the angle of incidence to the prism and the amount of correction of the measurement result, and is configured to detect the incident prism and the angle of incidence to the prism based on the position information received from the target device, and to correct the measurement result of the reflector based on the angle of incidence.

[0015] The present invention also relates to a surveying system in which the target device further comprises a pole installed at a measurement point and configured such that its axis passes through the reference point of the reflector, and a tilt detector capable of detecting the verticality of the pole, and the surveying device is configured to measure the measurement point based on the measurement result of the reflector and a known distance from the reference point to the lower end of the pole, and to correct the measurement result of the measurement point based on the angle of incidence to the prism.

[0016] The present invention further relates to a surveying system in which the target device comprises a pole installed at a measurement point and configured such that its axis passes through a reference point of the reflector, and a tilt detector capable of detecting the two-axis tilt of the pole with respect to the horizontal, and the surveying device is configured to measure the measurement point based on the measurement result of the reflector, the detection result of the tilt detector, and a known distance from the reference point to the lower end of the pole, and to correct the measurement result of the measurement point based on the angle of incidence to the prism.

[0017] The present invention also relates to a surveying system in which the target device further comprises a pole installed at the measurement point, configured such that its axis passes through the reference point of the reflector, the direction angle detector functions as a polarizing camera capable of detecting the left-right tilt relative to the surveying device, the surveying device emits distance measuring light of a predetermined polarization, measures the measurement point based on the measurement result of the reflector, the left-right tilt angle obtained by the polarizing camera, the front-back tilt angle and direction angle detected based on the angle of incidence to the prism, and a known distance from the reference point to the lower end of the pole, and corrects the measurement result of the measurement point based on the angle of incidence to the prism.

[0018] The present invention also relates to a surveying system in which the target device is a handheld scanner capable of acquiring point cloud data of an object to be measured, the handheld scanner further includes a tilt detector capable of detecting two-axis tilts with respect to the horizontal, and the surveying device is configured to convert the point cloud data acquired by the handheld scanner into point cloud data based on the installation position of the surveying device, based on the measurement result of the reflector and the detection result of the tilt detector, and to correct the point cloud data of the object to be measured based on the angle of incidence to the prism.

[0019] Furthermore, the present invention relates to a method for surveying a reference point using the above-described reflector, wherein the reflector of claim 1 is installed at least at known point 2 of known points 1 and 2, a surveying device is installed at new point 1, the known points 1 and 2 are measured by the surveying device, new point 1 is made known by the resection method, the direction angle of new point 1 is detected with the reflector of known point 2, then the surveying device is installed at new point 2, the known point 2 is measured from new point 2, the direction angle of new point 2 is detected with the reflector of known point 2, and new point 2 is made known based on the direction angle of new point 1 detected by the reflector, the direction angle of new point 2, and the measurement result obtained by measuring the known point 2 from new point 2. [Effects of the Invention]

[0020] According to the present invention, there is provided a prism unit that constitutes a wide-angle prism by a plurality of prisms arranged at least in part in the circumferential direction, and a direction angle detector disposed in a space formed within the prism unit such that the principal optical axis passes through a reference point located therein. A part of the incident light beam is configured to enter the prism unit, and the remaining part is configured to enter the direction angle detector. The direction angle detector includes a deflection optical member that deflects the light beam, an imaging lens, and a light receiving sensor. The light beam deflected by the deflection optical member enters the imaging lens, forms an image on the light receiving sensor by the imaging lens, and is configured to output position information including the incident angle of the light beam with respect to the deflection optical member based on the light receiving position of the light receiving sensor. Therefore, regardless of the incident direction to the reflector, the tilt angle with respect to the deflection optical member can be detected.

[0021] According to the present invention, there is also provided a surveying system having a target device provided with the above-described reflector and a surveying device capable of measuring the reflector. The target device has a communication unit for transmitting the light receiving position information emitted by the light receiving sensor to the surveying device. The surveying device preliminarily has table data associating the incident angle with respect to the prism and the correction amount of the measurement result. Based on the position information received from the target device, the incident prism and the incident angle with respect to the prism are detected, and the measurement result of the reflector is corrected based on the incident angle. Therefore, regardless of the incident direction to the reflector, a measurement result with errors removed can be obtained, and an excellent effect of improving the measurement accuracy can be exhibited.

Brief Description of the Drawings

[0022] [Figure 1] It is a cross-sectional view showing an optical system of a reflector according to a first embodiment. [Figure 2] (A) is a top view of a reflector according to a first embodiment, (B) is a cross-sectional view of a prism unit, and (C) is an explanatory diagram for explaining a light receiving region formed on a light receiving sensor. [Figure 3] It is an explanatory diagram showing a first surveying method using the reflector. [Figure 4]It is a graph associating the correction value of the incident angle with respect to the prism of the reflector and the distance. [Figure 5] It is an explanatory diagram showing a second surveying method using the reflector. [Figure 6] (A) is an explanatory diagram showing a third surveying method using the reflector, and (B) is an explanatory diagram for explaining a polarization camera. [Figure 7] It is an explanatory diagram showing a fourth surveying method using the reflector. [Figure 8] (A) and (B) are explanatory diagrams of the resection method for measuring a conventional new point. [Figure 9] (A) and (B) are explanatory diagrams showing a fifth surveying method for measuring a new point using the reflector. [Figure 10] (A) is a cross-sectional view showing the optical system of the reflector according to the second embodiment, and (B) is an explanatory diagram for explaining the light-receiving region formed on the light-receiving sensor. [Figure 11] It is a cross-sectional view showing the optical system of the reflector according to the third embodiment. [Figure 12] It is a cross-sectional view showing the optical system of the reflector according to the fourth embodiment. [Figure 13] (A) is a top view showing a first modified example of the prism part to which the direction angle detector according to the embodiment of the present invention is applicable, (B) is a perspective view of the prism part, and (C) is a cross-sectional view of the prism part. [Figure 14] (A) is a top view showing a second modified example of the prism part to which the direction angle detector according to the embodiment of the present invention is applicable, (B) is a perspective view of the prism part, and (C) is a cross-sectional view of the prism part.

Mode for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present invention will be described while referring to the drawings.

[0024] In FIGS. 1, 2(A) to 2(C), the reflector 1 according to the first embodiment of the present invention will be described.

[0025] The reflector 1 consists of a prism section 2 made up of multiple prisms and a direction angle detector 3 for detecting the direction of light incidence on the reflector 1.

[0026] The prism section 2 is a full-circumference prism acting as a retroreflector, and is composed of multiple prisms 4 as corner cubes arranged in the circumferential direction, for example, six prisms 4a to 4f. Each prism is, for example, in the shape of a regular triangular pyramid.

[0027] The prisms 4a to 4f are arranged alternately in the circumferential direction with their bottom surfaces inverted vertically. That is, the prism section 2 causes light from all 360° in the horizontal direction to be incident on one of the six prisms 4a to 4f and retroreflected. Therefore, the prism section 2 is capable of retroreflecting light from all 360° in the horizontal direction and from a range of approximately ±60° excluding the zenith and downwards, when the principal optical axis O of the direction angle detector 3, which will be described later, is vertical.

[0028] Of the six prisms 4a to 4f arranged in the circumferential direction, adjacent prisms 4a and 4b have different heights at the vertices of their triangular pyramids, i.e., the corner vertices, with the corner vertex of prism 4b being located below the corner vertex of prism 4a.

[0029] Furthermore, regarding the relative positions of other adjacent prisms 4, the corner vertex of prism 4c is located above the corner vertex of prism 4b, the corner vertex of prism 4d is located below the corner vertex of prism 4c, the corner vertex of prism 4e is located above the corner vertex of prism 4d, the corner vertex of prism 4f is located below the corner vertex of prism 4e, and the corner vertex of prism 4a is located above the corner vertex of prism 4f. In this case, the heights of the corner vertices of prisms 4a, 4c, and 4e are the same, and the heights of the corner vertices of prisms 4b, 4d, and 4f are the same.

[0030] Therefore, if we define a prism 4 whose corner vertex is located above an adjacent prism 4 as the upper prism 4, and a prism 4 whose corner vertex is located below an adjacent prism 4 as the lower prism 4, then prisms 4a, 4c, and 4e become the upper prism 4, and prisms 4b, 4d, and 4f become the lower prism 4. In other words, the corner vertices of prisms 4a to 4f are alternately positioned in the upper or lower prisms in order to align the height of the optical centers horizontally. Here, the optical center refers to the measurement reference point located inside each corner cube prism.

[0031] Furthermore, the upper side of the bottom surface of the upper prisms 4a, 4c, and 4e, and the lower side of the bottom surface of the lower prisms 4b, 4d, and 4f may be chamfered. Chamfering can reduce the vertical size of the prism section 2.

[0032] As described above, adjacent prisms 4 are arranged so that their bottom surfaces are inverted, and their inclination directions relative to the horizontal are also reversed. As a result, the direction of refraction of light incident on the prisms 4 is also reversed, and the horizontal height of the optical centers A of the upper prisms 4a, 4c, and 4e and the optical centers B of the lower prisms 4b, 4d, and 4f can be aligned. Furthermore, the center of the circle passing through each optical center at this time, or the center of the circle approximating each optical center, is the reference point 1a of the reflector 1. The distance between the reference point 1a and the optical centers of each prism 4a to 4f is known.

[0033] In this embodiment, the positions of the corner vertices of adjacent prisms 4, for example, prism 4a and prism 4b, are shifted vertically so that the vertical heights of the retroreflected light match, especially near the horizontal where the reflector 1 is frequently used. Therefore, the reflector 1 is configured so that there is no error in the measured vertical angle near the horizontal, regardless of which of the prisms 4a to 4f the light is incident on.

[0034] Furthermore, a space 5 is formed in the center of the prism section 2, and the reference point 1a is located within this space 5. In addition, recesses are formed in the zenith direction and downward direction of the prism section 2, and the direction angle detector 3 is positioned in these recesses.

[0035] Next, the details of the direction angle detector 3 will be described. In Figure 1, the upper side relative to the plane of the paper is referred to as "up," the lower side relative to the plane of the paper is referred to as "down," the right side relative to the plane of the paper is referred to as "right," and the left side relative to the plane of the paper is referred to as "left."

[0036] The direction angle detector 3 has a principal optical axis O, and is positioned such that the principal optical axis O passes through the reference point 1a. The direction angle detector 3 also includes a front lens group 6 as a deflection optical member provided on the principal optical axis O, an aperture plate 7, an imaging lens group 8 consisting of a group of convex lenses as an imaging lens, an ambient light cut filter 9, and a light receiving sensor 11.

[0037] The front lens group 6 is, for example, a single concave lens, and has a side surface 6a into which a portion of the light rays 12 incident on the prism 4 enters, an upper surface 6b, and a lower surface 6c in which a recess is formed. The front lens group 6 may be a cemented concave lens made up of multiple lenses, or a group of concave lenses made up of multiple lenses.

[0038] The side surface 6a is, for example, a cylindrical surface coated with an Anti-Reflection (AR) coating, and is configured to cause the incident light ray 12 to be incident on the lower surface 6c at an angle greater than or equal to a critical angle. Note that the side surface 6a is not limited to a cylindrical surface, but may also be a toric surface or an axisymmetric free-form surface.

[0039] The upper surface 6b is, for example, an axisymmetric free-form surface including a sphere or an aspherical surface, and is coated with a reflective coating over its entire surface. The lower surface 6c is also, for example, an axisymmetric free-form surface including a sphere or an aspherical surface, and is coated with an anti-reflective coating over its entire surface. The lower surface 6c is configured to totally reflect light rays 12 incident at or above a critical angle, and to totally transmit light rays 12 incident at or below a critical angle.

[0040] Furthermore, the lower surface 6c may be coated with a beam splitter film that reflects 50% of the light and transmits 50% of the light. This allows the light rays 12 that have passed through the side surface 6a to be reflected even if their incident angle is less than the critical angle, thereby improving the design flexibility.

[0041] The aperture plate 7 is a plate material with a hole of a predetermined size formed on the principal optical axis O, allowing only the light rays 12 passing through the hole to pass through, and blocking the light rays 12 passing through other optical paths, i.e., stray light. Furthermore, the aperture plate 7 is located within the space 5, and the position of the hole coincides with or substantially coincides with the reference point 1a.

[0042] The imaging lens group 8 is composed of multiple lenses and forms an image of the light rays 12 that have passed through the holes in the aperture plate 7 onto the light receiving sensor 11. The ambient light cut filter 9 is, for example, a bandpass filter or a dichroic filter that transmits only the light rays 12, and is capable of removing light of wavelengths other than the light rays 12, such as ambient light.

[0043] The light-receiving sensor 11 is a 2D sensor protected by protective glass 13 and is composed of a collection of pixels. Each pixel has pixel coordinates (x:y) with the principal optical axis O as the origin, and its position on the light-receiving sensor 11 is determined by these pixel coordinates. Each pixel outputs position information (pixel coordinates) along with the received light signal. A 2D image sensor such as a CCD or CMOS is used as the light-receiving sensor 11.

[0044] Here, the light ray 12 incident on the reflector 1 has a light-receiving position on the light-receiving sensor 11 determined by the incident position on the side surface 6a of the front lens group 6 and the incident angle on the side surface 6a at that time. That is, a region 14 into which the light ray 12 is incident is formed on the light-receiving sensor 11, and the light ray 12 is configured to be incident at a position within the region 14 corresponding to the incident position and incident angle on the side surface 6a. Note that the region 14 is an annular region excluding the center of the light-receiving sensor 11, as shown in Figure 2(C).

[0045] On the other hand, even if the incident positions on the side surface 6a are different, the receiving positions of the light rays 12 within the region 14 may overlap. However, when the receiving positions overlap, the incident angles on the side surface 6a match regardless of the incident position on the side surface 6a. Therefore, regardless of the incident position on the side surface 6a, the relationship between the receiving position of the light rays 12 and the incident angle on the side surface 6a is determined, and the incident angle of the light rays 12 can be calculated based on the receiving position of the light rays 12 within the region 14.

[0046] When the light ray 12 enters the reflector 1, a portion of the light ray 12 enters the prism portion 2 and is retroreflected, while the remainder enters the direction angle detector 3. The direction angle detector 3 can detect the angle (horizontal and vertical) at which the light ray 12 entered the side surface 6, based on which position (pixel) in the region 14 the light ray 12 was received by.

[0047] Furthermore, the detection of the incident angle (horizontal angle and vertical angle) of the light ray 12 may be performed by a surveying device that measures the reflector 1 based on the received light signal and position information from the light receiving sensor 11, by a control device separately provided on the reflector 1, or by a portable terminal (not shown) held by the worker.

[0048] Next, a first surveying method using the surveying system 15 having the reflector 1 will be described in Figure 3. In the following description, the distance measuring light 24 emitted from the surveying device 16 is referred to as the light ray 12 incident on the reflector 1.

[0049] The surveying system 15 comprises the surveying device 16 and the target device 18. The surveying device 16 is, for example, a total station capable of measurement (distance measurement and angle measurement) and tracking.

[0050] Furthermore, the target device 18 includes the reflector 1 mounted on the base 19, a pole 21 extending downward from the lower surface of the base 19 with a pointed lower end, a tilt detector 22, such as a bubble tube, provided on the base 19, and a communication unit 23 provided on the base 19 that can communicate wirelessly with the surveying device 16. The reference point 1a of the reflector 1 is located on the axis of the pole 21, and the distance between the reference point 1a and the lower end of the pole 21 is known. Also, the axis of the pole 21 and the principal optical axis O of the direction angle detector 3 coincide.

[0051] Furthermore, the base 19 may be integrated with the reflector 1. For example, as shown in Figure 3, the imaging lens group 8, the ambient light cut filter 9, and the light receiving sensor 11 may be built into the base 19, and the prism section 2 and the front lens group 6 may be exposed to the outside. That is, it is sufficient that the prism section 2 (the prism 4) into which the light rays 12 to be retroreflected are incident, and the front lens group 6 into which the light rays 12 are incident to detect the direction angle are exposed to the outside.

[0052] When performing surveying work using the surveying device 16 and the target device 18, first, the surveying device 16 is made to emit a distance measuring light 24 of a predetermined wavelength and a tracking light 25 of a different wavelength from the distance measuring light 24, and the reflector 1 is tracked via the tracking light 25. In this state, the target device 18 is transported to a predetermined measurement point 26, and the target device 18 is set up so that the measurement point 26 and the lower end of the pole 21 coincide.

[0053] Furthermore, instructions for distance measurement and tracking may be given from the surveying device 16, by the operator via a mobile device such as a smartphone or tablet (not shown), or by the target device 18 via the communication unit 23.

[0054] Furthermore, after the target device 18 is positioned vertically based on the tilt detector 22, the surveying device 16 is instructed to measure the reflector 1. The surveying device 16 emits the distance measuring light 24 and the tracking light 25 coaxially, and the measurement is performed in parallel with the tracking of the reflector 1.

[0055] A portion of the distance measuring light 24 and the tracking light 25 enters one of the prisms 4a to 4f, and the remainder enters the side surface 6a of the front lens group 6, i.e., the direction angle detector 3. The distance measuring light 24 and the tracking light 25 that enter the prisms 4a to 4f are retroreflected as reflected distance measuring light and reflected tracking light.

[0056] The remaining portions of the distance measuring light 24 and the tracking light 25 are incident on the direction angle detector 3, and the light reception result of the distance measuring light 24 by the direction angle detector 3 is transmitted to the surveying device 16 via the communication unit 23.

[0057] That is, the remaining portions of the distance measuring light 24 and the tracking light 25 are internally reflected by the front lens group 6, pass through the holes in the aperture plate 7, and are focused by the imaging lens group 8. Furthermore, after the ambient light and the tracking light 25 are removed by the ambient light cut filter 9, only the distance measuring light 24 is incident on a predetermined pixel in the region 14 on the light receiving sensor 11, corresponding to the incident position and incident angle with respect to the side surface 6a.

[0058] The light receiving sensor 11 outputs position information (pixel coordinates) along with the light receiving signal when a pixel receives the distance measuring light 24. The output light receiving signal and position information are transmitted to the surveying device 16 via the communication unit 23.

[0059] Furthermore, the light-receiving position within the region 14 into which the distance-measuring light 24 is incident is determined by the incident position and incident angle (horizontal angle and vertical angle) of the front lens group 6 relative to the side surface 6a. Moreover, if the light is received at the same light-receiving position, the incident angle will be the same even if the incident position is different. Therefore, if the light-receiving position of the distance-measuring light 24 at the light-receiving sensor 11 is known, the incident angle relative to the side surface 6a can be determined. Accordingly, the position information output from the light-receiving sensor 11 can be considered as position information including the incident angle relative to the direction angle detector 3.

[0060] The surveying device 16 calculates the incident angle (horizontal angle and vertical angle) of the distance measuring light 24 with respect to the front lens group 6 based on the detection result of the direction angle detector 3 received from the target device 18, i.e., the received light signal and position information, and calculates correction information based on the calculated incident angle.

[0061] Furthermore, the surveying device 16 corrects the measurement (distance measurement and angle measurement) results of the reflector 1 based on the obtained correction information, and calculates the three-dimensional coordinates of the measurement point 26 based on the corrected measurement results, the distance between the optical center of the prism 4 and the reference point 1a of the reflector 1, and the known distance from the reference point 1a to the lower end of the pole 21.

[0062] Here, the measurement result of the reflector 1 may be subject to error depending on the orientation of the reflector 1 relative to the surveying device 16, that is, at what angle (horizontal angle and vertical angle) the distance measuring light 24 (the tracking light 25) as the light ray 12 is incident on the reflector 1. This error can be related to the vertical angle (inclination angle) of the distance measuring light 24 with respect to the horizontal and the horizontal angle (direction angle) with respect to the principal optical axis O of the direction angle detector 3 as the vertical orientation.

[0063] For example, when correcting the distance measurement results, the distance correction amount for each horizontal and vertical angle of the reflector 1 is calculated in advance, or the correction amount is measured at the factory before shipment, thereby creating a table of distance correction amounts that associates the horizontal and vertical angles with the distance correction values.

[0064] Furthermore, as shown in Figure 4, the table data can be linearly interpolated or converted into a quadratic function, and based on this function and the horizontal and vertical angles detected by the direction angle detector 3, a distance correction amount, which is correction information when measuring the reflector 1, can be determined. In addition, by correcting the distance measurement result with the determined distance correction amount, an error-free distance measurement result can be obtained.

[0065] Similarly, for horizontal and vertical angles, table data representing the difference between the measured horizontal and vertical angles and the actual horizontal and vertical angles, i.e., the angle correction amount, can be created in advance through calculation or actual measurement. This table data can then be converted into a function of a quadratic variable using linear interpolation, and the angle correction amount, which is the correction information when measuring the reflector 1, can be determined based on this function and the horizontal and vertical angles detected by the direction angle detector 3. Furthermore, by correcting the measured angle results, i.e., the horizontal and vertical angles, with the determined angle correction amount, error-free measured angle results can be obtained. Note that the distance correction amount and the angle correction amount may be collectively referred to as the correction amount.

[0066] Furthermore, based on the corrected distance measurement results and angle measurement results (measurement results), the distance between the reference point 1a of the reflector 1 and the optical center of the prism 4, and the known distance from the reference point 1a to the lower end of the pole 21, the three-dimensional coordinates of the measurement point 26 can be determined with high accuracy.

[0067] Furthermore, the correction of the measurement results based on the correction information received from the target device 18 may be performed each time the reflector 1 is measured. Alternatively, the measurement results of the reflector 1 and the correction information from the target device 18 may be associated and saved, and the measurement results may be corrected after all the measurements of the measurement points 26 have been completed. In this case, the measurement results and correction information may be stored in the surveying device 16, or they may be stored in a portable terminal (not shown) held by the operator.

[0068] Furthermore, in the first embodiment, the distance measuring light 24 is used as the light ray 12, but the tracking light 25 may also be used as the light ray 12. In other words, any light having a specific wavelength can be used as the light ray 12 in this embodiment.

[0069] As described above, in the first embodiment, the reflector 1 is composed of a prism section 2 made up of a plurality of triangular pyramidal prisms 4, and a direction angle detector 3 positioned such that the principal optical axis O passes through the reference point 1a of the reflector 1, and is configured such that a portion of the light rays 12 incident on the prism section 2 are incident on the direction angle detector 3.

[0070] Furthermore, the direction angle detector 3 is capable of detecting the angle of incidence (horizontal angle and vertical angle) with respect to the side surface 6a of the front lens group 6 based on the position where the light ray 12 is received by the light receiving sensor 11.

[0071] Therefore, the reflector 1 retroreflects the incident light ray 12 and can also detect the angle of incidence relative to the front lens group 6.

[0072] Furthermore, the side surface of the front lens group 6 is used as the incident surface for the light ray 12 to the direction angle detector 3. Therefore, the reflector 1 can receive the light ray 12 in a range of approximately 360° horizontally and ±60° vertically, and can detect the incident angle to the front lens group 6.

[0073] Furthermore, the prism section 2 has six prisms 4a to 4f arranged alternately in the circumferential direction, with their lower base surfaces inverted vertically. Therefore, the reflector 1 can receive and retroreflect the light rays 12 in a range of approximately 360° horizontally and ±70° vertically.

[0074] Furthermore, in the first embodiment, in the prism section 2, each prism 4 is arranged such that the positions of the corner vertices of adjacent prisms 4, 4 are shifted vertically. Therefore, in the horizontal range where the reflector 1 is frequently used, the height of the retroreflected light rays 12 can be matched regardless of the prism 4 into which the light rays 12 are incident, thereby suppressing vertical angle errors caused by differences in the prism 4 into which the light rays 12 are incident.

[0075] Furthermore, when performing prism measurement using the reflector 1, the distance and angle errors that occur when measuring the reflector 1 can be corrected based on the position information received from the direction angle detector 3. This allows for the removal of errors from the measurement results and improves measurement accuracy.

[0076] Furthermore, when conducting a survey, the target device 18 only needs to be set up in a vertical position, and there is no need to consider the direction of the reflector 1 relative to the surveying device 16 or the angle of the reflector 1 relative to the surveying device 16, thus improving the work efficiency in surveying operations.

[0077] In the first embodiment, the case in which the lower end of the pole 21 is aligned with the measurement point 26 and the target device 18 is in a vertical position to measure the reflector 1 was described, but the surveying method using the reflector 1 is not limited to this.

[0078] For example, Figure 5 shows a second surveying method using the surveying system 15, in which a tilt detector 27 capable of detecting two-axis tilt, such as a tilt sensor, may be provided on the base 19. By configuring the tilt detector 27 to be capable of detecting two-axis tilt, it becomes possible to measure the reflector 1 without having to position the target device 18 vertically.

[0079] In other words, in addition to the tilt angle in the front-to-back direction (pitch) and the tilt angle in the left-to-right direction (roll) relative to the surveying device 16, which can be detected by the tilt detector 27, the direction angle detector 3 detects the direction angle (yaw), which cannot be detected by the tilt detector 27, thereby enabling measurement of the reflector 1. The tilt angle in the front-to-back direction relative to the surveying device 16 can also be calculated based on the detection result of the direction angle detector 3 and the vertical angle when the surveying device 16 measures the reflector 1.

[0080] Therefore, even at measurement points 26 in locations where the target device 18 cannot be installed in a vertical position, such as the corners of room 28, the measurement results can be corrected based on the detection results of the direction angle detector 3 and the tilt detector 27, enabling highly accurate measurements.

[0081] In the case of the tilt detector 27, it is not possible to determine whether the lower end of the pole 21 is above or below the reference point 1a of the reflector 1. Therefore, when taking measurements, it is necessary to input the vertical position relative to the reflector 1 separately.

[0082] Furthermore, Figures 6(A) and 6(B) show a third surveying method using the surveying system 15, in which a polarizing camera may be used to detect the tilt angle (roll) of the target device 18 relative to the surveying device 16 in the left-right direction. In this case, the light receiving sensor 29 of the direction angle detector 3 is a polarizing sensor as shown in Figure 6(B), and the distance measuring light 24 or tracking light 25 used as the light ray 12 is polarized light with a predetermined polarization direction.

[0083] The light-receiving sensor 29 has different pixels capable of receiving light depending on the polarization direction of the incident light ray 12. For example, if the polarization is 0°, the amount of light received is greatest in region 29a, closest to 0 in region 29c, and half as much in regions 29b and 29d as in region 29a (the region with the greatest amount of light received). If the polarization direction of the light ray 12 perfectly matches 0°, 45°, 90°, or 135°, light-receiving signals can be obtained from three of the regions 29a to 29d. On the other hand, if the polarization direction of the light ray 12 does not perfectly match 0°, 45°, 90°, or 135°, light-receiving signals can be obtained from all four of the regions 29a to 29d. Therefore, the polarization direction of the light ray 12 can be calculated based on the region from which the light-receiving signal is emitted from the light-receiving sensor 29 and the amount of light received in each region.

[0084] The polarization direction of the light ray 12 incident on the direction angle detector 3 changes with the left-right tilt angle (roll) relative to the surveying device 16. Therefore, by identifying the regions 29a to 29d from which the light receiving signal is emitted from the light receiving sensor 29, and further determining the ratio of the amount of light received in each region 29a to 29d, the left-right tilt angle of the target device 18 can be calculated.

[0085] Furthermore, based on the detection results of the direction angle detector 3, the direction angle and the tilt angle in the front-rear direction of the target device 18 can be determined. Therefore, highly accurate measurements with error correction become possible without having to position the target device 18 in a vertical orientation.

[0086] Furthermore, when using a polarizing camera, the tilt detector 27 can be omitted. Also, as with the case where the tilt detector 27 is provided, it is necessary to separately input the up and down direction relative to the reflector 1.

[0087] Figure 7 shows a fourth surveying method using the surveying system 15, in which the reflector 1 may be provided on a portable handheld scanner 31 acting as a target device instead of the target device 18. The handheld scanner 31 is capable of acquiring three-dimensional point cloud data of a predetermined object to be measured 32 with respect to the machine center of the handheld scanner 31, and is capable of transmitting the three-dimensional point cloud data to the surveying device 16. Furthermore, the handheld scanner 31 incorporates a tilt detector (not shown) equivalent to the tilt detector 27, and is capable of detecting two-axis tilt angles with respect to the horizontal.

[0088] The yaw angle relative to the surveying device 16 when it measures the reflector 1 can be determined based on the detection result of the yaw angle detector 3, and the inclination angle relative to the horizontal can be detected by the inclination detector. Therefore, the surveying device 16 can calculate three-dimensional point cloud data of the object to be measured 32 with the surveying device 16 as the reference, based on the inclination angle and yaw angle of the two axes and the measurement result of the reflector 1. Furthermore, the surveying device 16 can correct the error in the measurement result based on the detection result of the yaw angle detector 3 and calculate highly accurate three-dimensional point cloud data.

[0089] Furthermore, the surveying device 16 is not limited to a total station; a laser scanner or a laser tracker may also be used. In the case of a conventional laser tracker, it is necessary to provide a light-emitting element such as an LED on the handheld scanner 31, have the laser tracker capture the light from the light-emitting element, and determine the orientation of the handheld scanner 31 based on the position of the light in the image. On the other hand, in this embodiment, the orientation of the handheld scanner 31 can be determined regardless of the orientation of the handheld scanner 31, thus improving work efficiency.

[0090] Furthermore, similar to Figures 6(A) and 6(B), it is also possible to determine the orientation of the handheld scanner 31 based on the detection results of the polarization camera and the direction angle detector 3. In this case, the tilt detector can be omitted.

[0091] Furthermore, by making the light receiving sensor 11 a color or monochrome sensor, the direction angle detector 3 can be a camera substantially coaxial with the reflector 1. When a camera is used, the approximate orientation of the surveying device 16 relative to the target device 18, that is, the approximate orientation of the target device 18 relative to the surveying device 16, can be determined based on the acquired image.

[0092] Therefore, by transmitting the specified orientation to the surveying device 16 in real time via the communication unit 23, the time it takes for the tracking light 25 to acquire the reflector 1 can be shortened, thereby speeding up the surveying work.

[0093] Figures 8(A) and 8(B) show a conventional surveying method, while Figures 9(A) and 9(B) show a fifth surveying method using the surveying system 15. The fifth surveying method is a control point surveying method that uses a laser scanner as the surveying device 16.

[0094] First, we will explain the conventional surveying method for conducting control point surveys in Figures 8(A) and 8(B).

[0095] STEP 01: Install the surveying device 16 at new point 1, install the reflector 1 at known point 1 and known point 2, measure known point 1 and known point 2 with the surveying device 16, find the coordinates of new point 1 using the resection method and make new point 1 known. The now known point is designated as known point 3.

[0096] STEP 02: Install the surveying device 16 at new point 2, leave the reflective target at known point 2 as is, and install a reflective target at known point 3. From new point 2, measure known points 2 and known points 3 using the surveying device 16, and make new point 2 known in the same way as in STEP 01.

[0097] Next, the method for measuring reference points according to the present invention using the reflector 1 of the above embodiment will be described in Figures 9(A) and 9(B).

[0098] STEP 11: Install the surveying device 16 at new point 1, install the reflective target at known point 1, install the reflector 1 (including the direction angle detector 3) of the present invention at known point 2, determine the coordinates of new point 1 using the resection method and make new point 1 known. The newly known new point 1 is designated as known point 3.

[0099] STEP 12 At this time, the direction angle detector 3 of the reflector 1 receives the distance measuring light 24 and detects the direction angle of the installation point (known point 3) of the surveying device 16 from the light reception result. Let the direction angle (horizontal angle) at this time be A.

[0100] STEP 13: Move the surveying device 16 to the next measurement point (new point 2) and install it at new point 2. At this time, the reflector 1 at known point 2 will remain in its initial installation state.

[0101] STEP 14 The surveying device 16 measures the known point 2 from the new point 2. The reflector 1 (direction angle detector 3) receives the distance measuring light 24 and detects the direction angle (horizontal angle) B of the new point 2 from the known point 2 from the light reception result. The horizontal angle C between the known point 3 and the new point 2 is determined by (BA).

[0102] From this horizontal angle C and the measurement results of known point 2 by the surveying device 16 at new point 2, new point 2 is identified as a known point.

[0103] In this embodiment, when a new point 2 is identified, it is not necessary to set a target at the known point 3, thus shortening the measurement time. Furthermore, since the measurement results can be corrected based on the detection results of the direction angle detector 3, highly accurate measurements with errors removed can be performed.

[0104] Next, a reflector 33 according to a second embodiment of the present invention will be described in Figures 10(A) and 10(B). In Figures 10(A) and 10(B), components equivalent to those in Figures 1 and 2(C) are denoted by the same reference numerals, and their descriptions are omitted.

[0105] In the second embodiment, the reflector 33 has a direction angle detector 34 which includes a first front lens group 35 as a first deflection optical member and a second front lens group 36 as a second deflection optical member. The prism section 2 is positioned between the first front lens group 35 and the second front lens group 36. The other configurations are the same as those of the reflector 1 in the first embodiment.

[0106] The first front lens group 35 has the same configuration as the front lens group 6 in the first embodiment. Specifically, the side surface 35a is a cylindrical surface, toric surface, or axially symmetric free-form surface with an AR coating, the upper surface 35b is an axially symmetric free-form surface with an AR coating applied over its entire surface, and the lower surface 35c is configured to totally reflect light rays 12 incident at an angle greater than or equal to the critical angle, and to totally transmit light rays 12 incident at an angle less than the critical angle.

[0107] Furthermore, the second front lens group 36 has a side surface 36a with the same configuration as the side surface 35a, and a bottom surface 36c with the same configuration as the bottom surface 35c. On the other hand, the top surface 36b has an AR coating in the center and a reflective coating everywhere except the center, so that the light rays 12 that have passed through the bottom surface 35c are incident on the center.

[0108] The side surface 35a can receive the light ray 12 in a range of approximately 0° to 60° when the horizontal direction is set to 0°, and the side surface 36a can receive the light ray 12 in a range of approximately -60° to 0° when the horizontal direction is set to 0°. Therefore, the direction angle detector 34 can receive the light ray 12 in a range of approximately 360° in the horizontal direction and -60° to 60° in the vertical direction. The light ray 12 that is about to enter the first front lens group 35 at an angle of less than 0° enters the prism section 2, and the light ray 12 that is about to enter the second front lens group 36 at an angle of 0° or more enters the prism section 2.

[0109] Furthermore, as shown in Figure 10(B), regions corresponding to the first front lens group 35 and the second front lens group 36 are formed on the light receiving sensor 11. That is, the light ray 12 incident on the first front lens group 35 is incident on one of the annular first region 37 formed on the light receiving sensor 11. Similarly, the light ray 12 incident on the second front lens group 36 is incident on one of the annular second region 38 formed on the light receiving sensor 11. Note that the inner diameter of the second region 38 is larger than the outer diameter of the first region 37, so that the first region 37 and the second region 38 do not overlap each other.

[0110] When a light ray 12 enters the reflector 33, a portion of it is retroreflected by one of the prisms 4 in the prism section 2, and the remainder enters the direction angle detector 34. At this time, if the incident angle of the light ray 12 with respect to the direction angle detector 34 is between 0° and 60°, the light ray 12 enters the first front lens group 35, and if the incident angle of the light ray 12 is between -60° and 0°, the light ray 12 enters the second front lens group 36.

[0111] The light ray 12 incident on the first front lens group 35 is internally reflected multiple times within the first front lens group 35, then passes through the second front lens group 36, the imaging lens group 8, etc., and is received at a predetermined position in the first region 37. Similarly, the light ray 12 incident on the second front lens group 36 is reflected multiple times within the second front lens group 36, then passes through the imaging lens group 8, etc., and is received at a predetermined position in the second region 38.

[0112] In response to the light received by the light receiving sensor 11, a light receiving signal and position information are emitted. Furthermore, based on this position information, it is possible to detect at what angle the light ray 12 was incident on either the first front lens group 35 or the second front lens group 36.

[0113] In the second embodiment, the same effects as in the first embodiment can be obtained. Furthermore, in the second embodiment, the deflection optical member is composed of two deflection optical members, the first front lens group 35 and the second front lens group 36, and each front lens group 35, 36 is capable of receiving the light rays 12 at different angular ranges.

[0114] Therefore, the incident range of the light rays 12 for each front lens group 35, 36 can be reduced, and each front lens group 35, 36 can be made smaller.

[0115] Next, a reflector 39 according to a third embodiment of the present invention will be described in Figure 11. In Figure 11, components equivalent to those in Figure 1 are denoted by the same reference numerals, and their descriptions are omitted.

[0116] In the third embodiment, the direction angle detector 41 has a fisheye lens 42 as a deflection optical element instead of the front lens group 6 (see Figure 1). The prism section 2 is positioned between the fisheye lens 42 and the light receiving sensor 11. The other configurations are the same as those of the reflector 1 (see Figure 1) in the first embodiment.

[0117] The fisheye lens 42 is, for example, a fisheye lens with a field of view exceeding 180°. By using the fisheye lens 42, the reflector 39 can secure a full 360° field of view in the horizontal direction and a vertical angle of approximately -30° to 60° in the vertical direction when the horizontal direction is set to 0°.

[0118] The light rays 12 incident on the fisheye lens 42 are received by the light receiving sensor 11 via the imaging lens group 8, etc. Furthermore, based on the light receiving position on the light receiving sensor 11 (region 14) at this time, it is possible to detect the incident angle at which the light rays 12 were incident on the fisheye lens 42.

[0119] In the third embodiment, the same effects as in the first embodiment can be obtained. Furthermore, in the third embodiment, since the fisheye lens 42 is used as the deflection optical element, the configuration is simplified and the design can be easily carried out.

[0120] Next, a reflector 43 according to a fourth embodiment of the present invention will be described in Figure 12. In Figure 12, components equivalent to those in Figure 1 are denoted by the same reference numerals, and their descriptions are omitted.

[0121] In the fourth embodiment, the direction angle detector 44 has a deflection prism 45 as a deflection optical element instead of the front lens group 6 (see Figure 1). The prism section 2 is positioned between the deflection prism 45 and the light receiving sensor 11. The other configurations are the same as those of the reflector 1 (see Figure 1) in the first embodiment.

[0122] The deflection prism 45 has an incident surface 45a into which the light ray 12 is incident, a reflecting surface 45b that internally reflects the light ray 12 incident from the incident surface 45a, and a transmitting surface 45c into which the light ray 12 reflected by the reflecting surface 45b is incident and transmitted. Since the light ray 12 is incident on the reflector 43 from all 360° in the horizontal direction, the incident surface 45a, the reflecting surface 45b, and the transmitting surface 45c are formed all 360° around the principal optical axis O.

[0123] Furthermore, the deflection prism 45 has an inclined surface 45d that slopes upward from the peripheral edge of the transmitting surface 45c so as to move away from the principal optical axis O, and the incident surface 45a is provided continuously from the upper end of the inclined surface 45d. The incident surface 45a has a cylindrical surface 45e that is directed parallel to the principal optical axis O, and the reflective surface 45b is formed continuously from the cylindrical surface 45e.

[0124] The incident surface 45a is, for example, an axially symmetric free-form surface coated with an AR coating, the reflective surface 45b is, for example, an axially symmetric free-form surface with a reflective film deposited on it, and the transmissive surface 45c is, for example, an axially symmetric free-form surface coated with an AR coating.

[0125] In the fourth embodiment, a portion of the light ray 12 incident on the reflector 43 enters the deflection prism 45 from the incident surface 45a, is internally reflected by the reflective surface 45b, passes through the transmissive surface 45c, and is then received by the light receiving sensor 11 via the imaging lens group 8, etc. Therefore, based on the position at which the light ray 12 is received by the light receiving sensor 11, it is possible to detect the incident angle at which the light ray 12 entered the incident surface 45a.

[0126] It goes without saying that even when using the reflectors of the second to fourth embodiments, the first to fifth surveying methods can still be implemented.

[0127] Furthermore, in the first to fourth embodiments, six truncated square pyramidal prisms 4 are arranged alternately in the upper and lower sections to form a full-circumference prism (prism section 2), but the arrangement and shape of the prisms 4 are not limited to these.

[0128] For example, as shown in the first modified example in Figures 13(A) to 13(C), the prism section 48 may be configured as a full-circumference prism by six truncated square pyramidal prisms 47a to 47f, each having a trapezoidal base. In this case, the prisms 47a to 47f are arranged alternately in the circumferential direction, with their lower bases inverted vertically relative to adjacent prisms 47.

[0129] Furthermore, as shown in the second modified example in Figures 14(A) to 14(C), the prism section 49 as a full-circumference prism may be composed of roughly conical prisms 51a to 51f, each having a circular base (incident surface) and three inclined surfaces. In this case, the prisms 51a to 51f are arranged circumferentially, rotated by a predetermined angle relative to the adjacent prism 51 around an axis passing through the center of the base. For example, the prisms 51a to 51f are arranged rotated by 60° around the axis relative to the adjacent prism.

[0130] The prism sections 48 and 49 described above are applicable to the reflectors according to the first to fourth embodiments, and it goes without saying that a reflector may be constructed by combining them with prism sections having configurations other than those described above.

[0131] Furthermore, in the first to fourth embodiments and their modifications, the full-circumference prism (prism section) is composed of at least six prisms arranged in the circumferential direction. However, the prism section of the reflector of the present invention is not limited to a full-circumference prism composed of six prisms. For example, a full-circumference prism may be composed of four prisms arranged in the circumferential direction, or of eight prisms arranged in the circumferential direction. That is, a full-circumference prism can be composed of multiple (at least two or more) prisms arranged in the circumferential direction and applied to the reflector in the first to fourth embodiments.

[0132] Furthermore, the prism section is not limited to a full-circumference prism. For example, in the first to fourth embodiments, one prism may be removed from the six prisms arranged in the circumferential direction, and a wide-angle prism may be constructed using the five prisms arranged in the circumferential direction, and this wide-angle prism may be applied to the reflector in the first to fourth embodiments. Here, wide angle means, for example, a range of 120° to 315°. The wide-angle prism may be constructed using four or fewer prisms arranged in the circumferential direction, or it may be constructed using seven or more prisms arranged in the circumferential direction. That is, a wide-angle prism can be constructed using at least multiple (at least two or more) prisms arranged in the circumferential direction and applied to the reflector in the first to fourth embodiments. [Explanation of Symbols]

[0133] 1 reflector 2 Prism section 3-way angle detector 4 Prisms 6. Front lens group 11. Light receiving sensor 12 rays 33 Reflector 39 Reflector 43 Reflector

Claims

1. A reflector comprising a prism section comprising a plurality of prisms arranged in at least a portion of the circumferential direction to constitute a wide-angle prism, and a direction angle detector positioned such that the principal optical axis passes through a reference point located in a space formed within the prism section, wherein a portion of the incident light ray enters the prism section and the remainder enters the direction angle detector, the direction angle detector comprising a deflection optical member for deflecting the light ray, an imaging lens, and a light receiving sensor, wherein the light ray deflected by the deflection optical member enters the imaging lens, is imaged by the imaging lens on the light receiving sensor, and outputs position information including the angle of incidence of the light ray to the deflection optical member based on the light receiving position of the light receiving sensor.

2. The reflector according to claim 1, configured such that the light rays incident on the deflecting optical member are received within a specific region on the light receiving sensor corresponding to the angle of incidence to the deflecting optical member.

3. The reflector according to claim 1, wherein the deflection optical member is a lens that internally reflects the light rays incident from the side multiple times.

4. The reflector according to claim 1, wherein the deflection optical member is a fisheye lens with a field of view of 180° or more.

5. The deflection optical member is a deflection prism having a reflective surface that internally reflects the light rays incident from the incident surface, and the reflecting surface is an axisymmetric free-form surface as described in claim 1.

6. The reflector according to any one of claims 1 to 5, wherein the prisms are arranged alternately in upper and lower rows such that the heights of the corner vertices are different.

7. The reflector according to any one of claims 1 to 5, wherein the prism is a square pyramidal prism with a trapezoidal base, and the prism portion is configured such that the prisms are alternately arranged in the circumferential direction while their lower bases are inverted vertically.

8. The reflector according to any one of claims 1 to 5, wherein the prism is a generally conical prism having a circular base and three inclined surfaces, and the prism portion is configured such that each prism is arranged in a state where it is rotated about an axis relative to the adjacent prism.

9. A surveying system comprising a target device provided with a reflector according to claim 1, and a surveying device capable of measuring the reflector, wherein the target device has a communication unit for transmitting light reception position information emitted by the light receiving sensor to the surveying device, the surveying device has pre-existing table data relating the angle of incidence to the prism and the amount of correction of the measurement result, and is configured to detect the incident prism and the angle of incidence to the prism based on the position information received from the target device, and to correct the measurement result of the reflector based on the angle of incidence.

10. The surveying system according to claim 9, wherein the target device further comprises a pole installed at a measurement point and configured such that its axis passes through a reference point of the reflector, and a tilt detector capable of detecting the verticality of the pole, and the surveying device is configured to measure the measurement point based on the measurement result of the reflector and a known distance from the reference point to the lower end of the pole, and to correct the measurement result of the measurement point based on the angle of incidence to the prism.

11. The surveying system according to claim 9, wherein the target device further comprises a pole installed at a measurement point and configured such that its axis passes through a reference point of the reflector, and a tilt detector capable of detecting the two-axis tilt of the pole with respect to the horizontal, and the surveying device is configured to measure the measurement point based on the measurement result of the reflector, the detection result of the tilt detector, and a known distance from the reference point to the lower end of the pole, and to correct the measurement result of the measurement point based on the angle of incidence to the prism.

12. The surveying system according to claim 9, wherein the target device further comprises a pole installed at the measurement point and configured such that its axis passes through the reference point of the reflector, the direction angle detector functions as a polarizing camera capable of detecting the tilt in the left-right direction relative to the surveying device, the surveying device emits distance measuring light of a predetermined polarization, measures the measurement point based on the measurement result of the reflector, the left-right tilt angle obtained by the polarizing camera, the front-back tilt angle and direction angle detected based on the angle of incidence to the prism, and a known distance from the reference point to the lower end of the pole, and corrects the measurement result of the measurement point based on the angle of incidence to the prism.

13. The surveying system according to claim 9, wherein the target device is a handheld scanner capable of acquiring point cloud data of an object to be measured, the handheld scanner further includes a tilt detector capable of detecting a two-axis tilt with respect to the horizontal, and the surveying device is configured to convert the point cloud data acquired by the handheld scanner into point cloud data based on the installation position of the surveying device, based on the measurement result of the reflector and the detection result of the tilt detector, and to correct the point cloud data of the object to be measured based on the angle of incidence to the prism.

14. A method for surveying a reference point using a reflector according to claim 1, wherein the reflector according to claim 1 is installed at least known point 2 of known points 1 and 2, a surveying device is installed at new point 1, the known points 1 and 2 are measured by the surveying device, new point 1 is made known by the resection method, the direction angle of new point 1 is detected with the reflector at known point 2, then the surveying device is installed at new point 2, the known point 2 is measured from new point 2, the direction angle of new point 2 is detected with the reflector at known point 2, and new point 2 is made known based on the direction angle of new point 1 detected by the reflector, the direction angle of new point 2, and the measurement result obtained by measuring the known point 2 from new point 2.

Images