Surveying equipment, surveying methods, and surveying programs

Abstract

To provide a technology which can easily find the attitude of a laser scanner.SOLUTION: A surveying device comprises: a sunlight incident direction detection unit 211 that detects an incident direction of sunlight to a laser scanner on the basis of a detected waveform of incident light entering the laser scanner; a sun direction acquisition unit 212 that acquires from astronomical data a direction of the sun as seen from the laser scanner, on the basis of the position of the laser scanner; and an attitude calculation unit 213 that calculates the attitude of the laser scanner in an absolute coordinate system, on the basis of the incident direction of the sunlight and the direction of the sun as seen from the laser scanner obtained from the astronomical data.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to laser scanning technology.

Background Art

[0002] For example, laser scanning is used as a surveying means at a construction site. At this time, it is necessary to first determine the position and orientation of the laser scanning device (see, for example, Patent Document 1). The position can be determined with high accuracy by relative positioning using GNSS. The orientation can be determined using an IMU or a high-precision compass.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The method using an IMU or a high-precision compass requires the preparation of dedicated expensive equipment and also requires separate precise work for that purpose. Against this background, an object of the present invention is to provide a technique capable of easily determining the orientation of a laser scanning device.

Means for Solving the Problems

[0005] The present invention is a surveying device including a sunlight incident direction detection unit that detects the incident direction of sunlight on the laser scanning device based on the detection waveform of the incident light incident on the laser scanning device, a sun direction acquisition unit that acquires the direction of the sun as seen from the laser scanning device from astronomical data based on the position of the laser scanning device, and an orientation calculation unit that calculates the orientation of the laser scanning device in an absolute coordinate system based on the incident direction of the sunlight and the direction of the sun as seen from the laser scanning device obtained from the astronomical data.

[0006] In the present invention, the detection unit for detecting the incident direction of sunlight can be configured to detect the incident direction of sunlight on the condition that input light is continuously detected within an angular range corresponding to the apparent diameter of sunlight.

[0007] In the present invention, the laser scanning device performs laser scanning at an angular interval Δθ shorter than the apparent diameter of the sun, and in the angular range corresponding to the apparent diameter of the sun. but The aforementioned Δθ On the condition that the incident light is continuously detected within an angular range of at least twice that of the given range. One example of this invention is the detection of the direction of incidence of sunlight. Another example of this invention is the ability to change the setting of the apparent diameter according to the weather.

[0008] The present invention is a surveying method that detects the direction of incidence of sunlight on a laser scanning device based on the detection waveform of incident light incident on the laser scanning device, obtains the direction of the sun as seen from the laser scanning device from astronomical data based on the position of the laser scanning device, and calculates the attitude of the laser scanning device in an absolute coordinate system based on the direction of incidence of sunlight and the direction of the sun as seen from the laser scanning device obtained from the astronomical data.

[0009] The present invention is a surveying program that is read and executed by a computer, and the computer functions as follows: a sunlight incidence direction detection unit that detects the direction of sunlight incident on a laser scanning device based on the detection waveform of incident light incident on the laser scanning device; a sun direction acquisition unit that acquires the direction of the sun as seen from the laser scanning device from astronomical data based on the position of the laser scanning device; and an attitude calculation unit that calculates the attitude of the laser scanning device in an absolute coordinate system based on the sunlight incidence direction and the direction of the sun as seen from the laser scanning device obtained from the astronomical data. [Effects of the Invention]

[0010] According to the present invention, the orientation of the laser scanning device can be easily determined. [Brief explanation of the drawing]

[0011] [Figure 1] This is a diagram illustrating the overview of laser scanning. [Figure 2] This is a diagram showing the external appearance of a laser scanning device. [Figure 3] This is a block diagram of the laser scanning device and processing unit. [Figure 4] This is a flowchart showing an example of the processing procedure. [Figure 5] This waveform diagram shows examples of detection waveforms for reflected light from an object and sunlight. [Modes for carrying out the invention]

[0012] 1. First Embodiment (overview) Figure 1 shows the laser scanning device 200, a surveying device, installed at the site where point cloud data acquisition is to be performed. Figure 1 also shows a bridge 400 as an example of the target for point cloud data acquisition. The sun 100 is also shown in the sky. Although the orientation of the laser scanning device 200 is unknown, it is assumed to be installed as horizontally as possible.

[0013] In this example, the position of the laser scanning device 200 is first determined using GNSS or similar means. Then, the laser scanning device 200 performs a full-circumference scan to detect the direction of the sun. The laser scanning light is pulsed light, but sunlight is not pulsed light, so the output waveform of the light receiving section of the laser scanning device will be different from that of the reflected light from the laser scanning light. Specifically, the detected waveforms of the two will be different.

[0014] The differences in the detected waveforms described above allow for the identification of sunlight and the acquisition of its direction. On the other hand, if the time is known, the direction of the sun as seen from that location can be determined from astronomical data. Therefore, the measured direction of the sun as seen from the laser scanning device 200 is compared with the direction of the sun obtained from astronomical data to determine the attitude of the laser scanning device 200.

[0015] (Hardware Configuration) Figure 2 shows the appearance of a laser scanning device (laser scanner) 200. The laser scanning device 200 includes a tripod 311, a base portion 312 fixed to the upper part of the tripod 311, a horizontal rotating portion 313 that is a rotating body capable of horizontal rotation on the base portion 312, and a vertical rotating portion 314 that is a rotating body capable of vertical rotation with respect to the horizontal rotating portion 313. Also, an operation panel (not shown) is arranged on the back surface of the horizontal rotating portion 213.

[0016] The vertical rotating portion 314 includes an optical unit 315 that emits and receives laser scanning light. Laser scanning light is emitted in pulses from the optical unit 315. This pulsed emission is performed along a direction (vertical plane) orthogonal to the rotation axis (axis extending in the horizontal direction) while the vertical rotating portion 314 rotates. In this case, laser scanning light is emitted in pulses from the optical unit 315 along the direction of the vertical angle (angle directions of elevation and depression).

[0017] While horizontally rotating the horizontal rotating portion 313 and vertically rotating the vertical rotating portion 314, laser scanning light is emitted in pulses from the optical unit 315, and the reflected light from the object is received by the optical unit 315, thereby performing laser scanning of the surroundings.

[0018] Simultaneously with the scan (vertical scan) along the above-described vertical angle direction, when the horizontal rotating portion 313 rotates horizontally, the scan line (vertical scan line) along this vertical angle direction moves while being shifted along the horizontal angle direction (horizontal direction). When horizontal rotation is also performed simultaneously during vertical rotation, the scan (vertical scan line) along the vertical angle direction is not completely along the vertical direction but is a slightly slanted line. If the horizontal rotating portion 313 does not rotate, the scan (vertical scan line) along the vertical angle direction will be along the vertical direction.

[0019] The rotations of the horizontal rotation part 313 and the vertical rotation part 314 are performed by a motor. The horizontal rotation angle of the horizontal rotation part 313 and the vertical rotation angle of the vertical rotation part 314 are precisely measured by an encoder.

[0020] Each laser scan light is a single pulse ranging light, and with one laser scan light, the distance measurement of the scan point, which is the reflection point hit by the laser scan light, is performed. From this distance measurement value and the irradiation direction of the laser scan light, the position of the scan point (the reflection point of the laser scan light) with respect to the laser scanning device 200 is calculated.

[0021] As the form of the laser scan point cloud output from the laser scanning device 200, there is a form that outputs data on the distance and direction related to each point (each scan point). Inside the laser scanning device 200, it is also possible to calculate the position of each point in a specific coordinate system and output the three-dimensional coordinate positions of each point as point cloud data. Also, the data of the laser scan point cloud includes information on the luminance (intensity of the reflected light) of each scan point.

[0022] FIG. 3 is a block diagram of the laser scanning device 200. The laser scanning device 200 includes a light emitting part 201, a light receiving part 202, a distance measurement part 203, a direction acquisition part 204, a light emission control part 205, a drive control part 206, a communication device 207, a storage part 208, a laser scan control part 209, a GNSS position measurement device 210, a detection part 211 for the incident direction of sunlight, a direction acquisition part 212 for the sun, and an attitude calculation part 213.

[0023] The laser scanning device 200 incorporates a computer equipped with a CPU, a memory, a communication interface, a user interface, and a clock. Calculations related to positioning are performed by the computer. Also, the functions of the detection part 211 for the incident direction of sunlight, the direction acquisition part 212 for the sun, and the attitude calculation part 213 are realized by the computer.

[0024] The light-emitting unit 201 includes a light-emitting element that emits laser scan light, an optical system related to light emission, and peripheral circuits. The light-receiving unit 202 includes a light-receiving element that receives laser scan light, an optical system related to light reception, and peripheral circuits.

[0025] The distance measuring unit 203 calculates the distance from the laser scanning device 200 to the reflection point (scan point) of the laser scan light based on the output of the light receiving unit 202. In this example, a reference optical path is provided inside the laser scanning device 200. The laser scan light output from the light-emitting element is split into two; one is irradiated onto the target from the optical unit 315 as laser scan light, and the other is guided to the reference optical path as reference light.

[0026] The laser scan light reflected from the target and captured by the optical unit 315, and the reference light propagated along the above-mentioned reference optical path are combined and input to the light receiving unit 202. The laser scan light and the reference light have different propagation distances, so the reference light is detected by the light receiving element first, followed by the laser scan light.

[0027] Here, observing the output waveform of the photodetector, the detection waveform of the reference light is output first, followed by the detection waveform of the laser scan light after a time delay. The distance to the reflection point of the laser scan light is calculated from the phase difference (time difference) between these two waveforms. It is also possible to calculate the distance from the flight time of the laser scan light.

[0028] The direction acquisition unit 204 acquires the direction of the optical axis of the laser scan beam. The direction of the optical axis is obtained by measuring the angle of the optical axis in the horizontal direction (horizontal angle) and the angle of the optical axis in the vertical direction (elevation angle or depression angle). The direction acquisition unit 204 has a horizontal angle detection unit 204a and a vertical angle detection unit 204b.

[0029] The horizontal angle detection unit 204a detects the horizontal rotation angle of the horizontal rotation unit 213. Horizontal rotation is rotation with the vertical direction as the axis of rotation. The angle is detected by an encoder. The vertical angle detection unit 204b detects the vertical rotation angle (elevation angle or depression angle) of the vertical rotation unit 314. Vertical rotation is rotation with the horizontal direction as the axis of rotation. The angle is detected by an encoder.

[0030] By measuring the horizontal rotation angle of the horizontal rotating section 313 and the vertical rotation angle of the vertical rotating section 314, the direction of the optical axis of the laser scan beam as seen from the laser scanning device 200, i.e., the direction of the scan point, can be determined.

[0031] The light emission control unit 205 controls the timing of light emission of the laser scan light in the light emission unit 201. The drive control unit 206 includes a horizontal rotation drive control unit 206a that controls the drive to rotate the horizontal rotation unit 313 horizontally, and a vertical rotation drive control unit 206b that controls the drive to rotate the vertical rotation unit 314 vertically. The drive is performed by a motor.

[0032] The communication device 207 communicates with other devices. Communication is performed using wired, wireless LAN, mobile phone lines, etc. The storage unit 208 is composed of semiconductor memory and hard disk drives and stores the operation programs, data, and data obtained from the operation process and results of the laser scanning device 200 that are necessary for its operation.

[0033] The laser scan control unit 209 controls the operation of the laser scan device 200. The GNSS position measurement device 210 performs positioning using GNSS (Global Navigation Satellite System). If high accuracy is required, relative positioning is performed.

[0034] The sunlight incidence direction detection unit 211 detects the incidence direction of sunlight into the laser scanning device 200 based on the detection waveform of the incident light entering the laser scanning device 200. In this example, the sunlight incidence direction detection unit 211 acquires the incidence direction of incident light, as seen from the laser scanning device 200, which is estimated to be sunlight that satisfies specific conditions.

[0035] Here, sunlight is determined based on the following conditions. Sunlight is not pulsed light like scanning light (distance measuring light). Therefore, conditions are set that can be considered as the detection waveform of sunlight (output waveform of the photodetector), and incident light that satisfies these conditions is determined to be sunlight (first determination).

[0036] Figure 5 shows an example of the detection waveform of reflected light from an object during laser scanning and the detection waveform of sunlight. Since the laser scanning light is pulsed light, its reflected light has a pulsed waveform with a single peak, as shown in Figure 5. On the other hand, the detection waveform of sunlight does not have a pulsed waveform.

[0037] Note that the pulse waveform of the reflected laser scan light shown in Figure 5 is just one example; the pulse width, peak value, and waveform shape can vary considerably depending on the type of light-emitting element, driving method, distance to the target, output of the laser scan light, and the condition and reflectivity of the reflective surface of the target object.

[0038] Therefore, by determining the unique properties of the detected waveform of sunlight, it is determined whether or not sunlight has been detected. Specifically, by utilizing the unique characteristics of the detected waveform as illustrated in Figure 5, conditions for determining that sunlight is incident are defined, and the detected waveform that satisfies these conditions is determined to be sunlight. The direction of sunlight incident on the laser scanning device 200 is obtained as the direction of the optical axis (horizontal angle and vertical angle) at the timing of reception when sunlight is determined to be incident.

[0039] For example, whether or not a waveform is a detected waveform of incident sunlight is determined by a combination of several factors, such as whether or not a peak is detected within a specific time range, whether or not fluctuations in the waveform amplitude are detected within a specific time range, whether or not rising and falling edges of the waveform are detected within a specific time range, the length of the peak duration, the range of fluctuation in the wave height within a specific time range, and the slope of the rising and / or falling edges of the waveform.

[0040] The following is a specific example. For instance, suppose the pulse width of the laser scan light is 0.5 μs. This pulse width is determined by the light-emitting element and its driving circuit. In this case, if incident light exceeding a predetermined threshold is detected, and no single-peak waveform with a pulse height exceeding a predetermined value is detected within a time width of 2 μs, the incident light is determined to be sunlight.

[0041] Furthermore, in this example, a second determination is made in addition to the first determination described above. In the second determination, it is determined whether or not sunlight incidence was detected by determining whether or not light reception continued within an angular range based on the field of view angle (visual diameter) of the sun (second determination).

[0042] For example, if the vertical rotating part 314 rotates 20 times per second and the emission frequency of the scan light is 50 kHz, then in a 360° range along the circular plane, (50 × 10 3 2500 scan beams (360° / 2500 = 0.144°) are emitted. In this case, the distance between points is 360° / 2500 = 0.144°. In other words, the distance between adjacent scan points in terms of field of view is 0.144°. If the rotation speed of the vertical rotating part 314 is even slower, this distance will be even shorter.

[0043] On the other hand, the apparent diameter of the sun is approximately 0.5°. Therefore, in the above case, if incident light is continuously detected within an angular range of more than twice (or more than three times) 0.144°, it is determined to be sunlight. The upper limit of the angular range is appropriately around 1° (if it is greater than 1°, other factors should be suspected). Since the apparent diameter of the sun is approximately 0.5°, for example, if light reception continues over an angular range of 0.4° to 0.6°, it is also possible to determine that this is sunlight rather than reflected light from the scan point. This determination is performed not only in the vertical direction but also in the horizontal direction. This allows for the detection of the sun's presence from a two-dimensional extent.

[0044] Here, if both the first and second determinations are true (YES), it is determined that sunlight has been detected, and the direction of the center at that time is obtained. For example, suppose that a vertical scan detects sunlight in the elevation angle range of 80° to 80.5°. In this case, the sun is considered to be at an elevation angle of (80° + 80.5°) / 2 = 80.25°. A similar process is performed for the horizontal angle. This process is performed in the sunlight incidence direction detection unit 211.

[0045] When sunlight is scattered by fog or clouds, the apparent diameter of the sun increases. In such cases, the upper limit of the apparent diameter threshold determination range should be expanded from the aforementioned 0.4° to 0.6° to 0.4° to 1.0°. For example, multiple settings such as "Weather Mode 1" and "Weather Mode 2" could be established, and the apparent diameter threshold determination range could be changed as described above when a specific mode is selected.

[0046] For example, it is possible to obtain weather and cloud information for the area to be laser scanned from the internet or a database, and select the above weather mode based on that weather information. It is also possible to determine that if weather information indicating no sunshine is expected (e.g., cloudy or rainy) is obtained, sunlight cannot be detected and therefore the process for determining sunlight detection cannot be performed. Furthermore, it is possible to perform the sunlight detection determination using only one of the first or second determinations.

[0047] The solar direction acquisition unit 212 obtains the direction of the sun at the time the direction of sunlight was acquired from astronomical data. For example, there is software that can calculate the direction of the sun when the position (latitude, longitude, altitude) and time are input. This software is used to obtain the direction of the sun at that time.

[0048] The attitude calculation unit 213 calculates the attitude of the laser scanning device 200 based on the direction of sunlight as seen from the detected laser scanning device 200 and the direction of the sun as seen from the laser scanning device 200 obtained from astronomical data.

[0049] For example, suppose that, during the initial setup of the laser scanning device, the detected direction of the sun is 10° horizontally and 80° vertically relative to the reference direction. Here, the horizontal angle is measured clockwise when viewed from vertically above, and the vertical angle is measured as the elevation angle.

[0050] On the other hand, let's assume that the corresponding direction of the sun obtained from astronomical data is an azimuth of 180° (due south in the Northern Hemisphere) and an elevation of 80.5°. Here, the azimuth is measured clockwise from a vertically upward perspective, with north being 0°.

[0051] In this case, the horizontal angle of the reference direction of the laser scanning device 200 in the absolute coordinate system is 170° (10° from south to east), and the elevation reference in that direction is tilted 0.5° from the horizontal. Note that if the laser scanning device 200 is perfectly horizontal, no error will occur in the elevation direction.

[0052] In this way, the attitude of the laser scanning device 200 in the absolute coordinate system is determined. This process is performed in the attitude calculation unit 213. The absolute coordinate system is the coordinate system used in GNSS and maps.

[0053] Some or more of the laser scan control unit 209, GNSS position measuring device 210, sunlight incident direction detection unit 211, sun direction acquisition unit 212, and attitude calculation unit 213 may be external devices (external survey data processing devices) separated from the laser scan device 200. These external devices are, for example, PCs (personal computers). The positional relationship between the antenna of the GNSS position measuring device 210 and the optical origin of the laser scan device 200 must be determined in advance.

[0054] (An example of processing) Figure 4 shows an example of the processing procedure. The program that executes the processing shown in Figure 4 is stored in the memory of the computer built into the laser scanning device 200, and is read and executed by the CPU of the computer. It is also possible to store the program on a suitable storage medium and read it from there for use.

[0055] Prior to the process shown in Figure 4, the laser scanning device 200 is first installed at the site where the laser scan will be performed. After the laser scanning device 200 is installed, positioning is performed using GNSS to obtain the position of the laser scanner 200 (step S101). If higher positional accuracy is required, relative positioning is performed.

[0056] Next, a full-circumference scan is performed (step S102). There are two forms of full-circumference scanning: one performed under normal scanning conditions, and another in which a neutral density filter is inserted into the optical path to avoid saturation of the light-receiving unit 202 due to the strong incident sunlight, which would make it difficult to detect the incident light. Depending on the light-receiving element used, the latter form may be adopted to account for the effects of saturation. If the approximate direction of the sun is known, it is also possible to narrow the scanning direction.

[0057] In step S102, a full-circumference scan is performed to obtain light-receiving data. The light-receiving data includes the detected waveform of the incident light received by the light-receiving unit 202 (output waveform of the light-receiving element), and the relationship between the detected waveform and the time. The detected waveform of the incident light is obtained by digitizing the output of the light-receiving element of the light-receiving unit 202 using an A / D converter, and this is stored in the storage unit 208 in association with the time. In addition to the light-receiving data, point cloud data (distance values ​​and directions of scan points) may also be acquired during the full-circumference scan in step S102.

[0058] Next, based on the light reception data obtained in the full-circumference scan in step S102, the direction of incident sunlight is detected (step S103). That is, the incident sunlight is determined based on the detected waveform, and its direction is then detected. This process is performed by the sunlight incident direction detection unit 211. Here, an example has been described in which the process in step S103 is performed after the full-circumference scan in step S102, but the process in step S103 may be performed simultaneously with the scan, or in parallel with the scan with a delay.

[0059] Next, the direction of the sun at that time is obtained using astronomical data (step S104). This process is performed by the sun direction acquisition unit 212. Then, based on the results of steps S103 and S104, the attitude of the laser scanning device 200 in the absolute coordinate system is calculated (step S105). This process is performed by the attitude calculation unit 213.

[0060] In this manner, the attitude (orientation) of the solar laser scanning device 200 in the absolute coordinate system is acquired. This process does not require a high-precision compass or IMU, nor does it require any work related to them.

[0061] 2. Second Embodiment There is a concern that sunlight may be reflected off the walls of high-rise buildings and detected as such. This section explains countermeasures for this situation. In this example, in the determination in the first embodiment, if sunlight is determined to be present, it is further determined whether "surfaces were detected on both the upper / lower or left / right sides of the direction in which the sun was determined to be present." This determination is made based on the scan data. If it is the true sun, there will be no surfaces on either side of that direction. This process is performed by the sunlight incidence direction detection unit 211.

[0062] The above determination can also be made by asking, "Is a surface detected enclosing the direction identified as the sun?" or "Is a surface detected around the direction identified as the sun?" Note that a surface is not necessarily flat; it can also be curved (some high-rise buildings have curved walls).

[0063] 3. Others (Other 1) The invention can also be understood as a system invention. For example, the calculations in the sunlight incidence direction detection unit 211, the sun direction acquisition unit 212, and the attitude calculation unit 213 may be performed by cloud processing. In this case, the laser scan data is sent to a processing server, where the calculations in the sunlight incidence direction detection unit 211, the sun direction acquisition unit 212, and the attitude calculation unit 213 are performed, and data regarding the attitude of the laser scanning device is transmitted from the processing server to the laser scanning device and the user.

[0064] (Other 2) The area from which the sun is visible from the ground can be narrowed down to some extent once the region and time are determined. This can be used to set the initial scan range, thereby reducing the time required for the scan.

[0065] (Other 3) The position of the laser scanner 200 may be approximate. For example, the position of the laser scanner 200 may be determined using location information at the prefecture, city, town, or ward level, and this may be used as the location information in step S101. In this case, the error will be larger compared to when GNSS is used, but the approximate orientation of the laser scanner 200 can be determined.

[0066] (Other 4) The detection waveform of the reflected light from the laser scan, which is acquired in advance and serves as the basis for determining the actual incident light, may be a theoretical value.

[0067] (Other 5) It is possible that incident light that is not sunlight may be mistakenly identified as sunlight. For example, the light from vehicle or heavy machinery lights or searchlights may be mistakenly identified as sunlight. To prevent this misidentification, the laser scanning device acquires data on the approximate direction of the sun at the time of measurement from astronomical data. Even if sunlight is determined to be incident based on the detected waveform and its duration, the algorithm further determines whether the sun is present in that direction, and if it is outside the range where sunlight can be present, it is determined that the incident light is not sunlight. This method avoids the incorrect calculation of the attitude of the laser scanning device 200 based on incident light that is not sunlight. [Explanation of symbols]

[0068] 200... Laser scanning device, 311... Tripod, 312... Base unit, 313... Horizontal rotation unit, 314... Vertical rotation unit, 315... Optical unit.

Claims

1. A unit for detecting the direction of incident sunlight on a laser scanning device, which detects the direction of incident sunlight on the laser scanning device based on the detected waveform of the incident light incident on the laser scanning device, A solar direction acquisition unit that acquires the direction of the sun as seen from the laser scanning device based on the position of the laser scanning device, An attitude calculation unit calculates the attitude of the laser scanning device in an absolute coordinate system based on the incident direction of sunlight and the direction of the sun as seen from the laser scanning device, which is determined from the astronomical data. A surveying device equipped with [a specific feature].

2. The surveying apparatus according to claim 1, wherein the unit for detecting the incident direction of sunlight detects the incident direction of sunlight on the condition that input light is continuously detected within an angular range corresponding to the apparent diameter of sunlight.

3. The laser scanning device performs laser scanning at an angular interval Δθ shorter than the apparent diameter of the sun. The surveying device according to claim 2, which detects the incident direction of sunlight on the condition that the incident light is continuously detected in an angular range corresponding to the apparent diameter of the sunlight, which is at least twice the angular range of Δθ.

4. The surveying device according to claim 2 or 3, wherein the setting of the apparent diameter can be changed according to the weather.

5. The direction of sunlight incident on the laser scanning device is detected based on the detected waveform of the incident light entering the laser scanning device. Based on the position of the laser scanning device, the direction of the sun as seen from the laser scanning device is obtained from the astronomical data. Based on the incident direction of sunlight and the direction of the sun as seen from the laser scanning device, determined from the astronomical data, the attitude of the laser scanning device in the absolute coordinate system is calculated. Surveying method.

6. It is a program that is read and executed by a computer. Computer A unit for detecting the direction of incident sunlight on a laser scanning device, which detects the direction of incident sunlight on the laser scanning device based on the detected waveform of the incident light incident on the laser scanning device, A solar direction acquisition unit that acquires the direction of the sun as seen from the laser scanning device based on the position of the laser scanning device, An attitude calculation unit calculates the attitude of the laser scanning device in an absolute coordinate system based on the incident direction of sunlight and the direction of the sun as seen from the laser scanning device, which is determined from the astronomical data. A surveying program that enables the operation of a system.

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