JP7162450B2 - Displacement measurement method and displacement measurement system - Google Patents

Description

The present invention relates to a displacement measuring method and a displacement measuring system using a satellite positioning system, and more particularly to a displacement measuring method and a displacement measuring system suitable for measuring the lateral displacement of relatively stable objects including structures. .

2. Description of the Related Art Conventionally, when measuring the displacement of a structure using a satellite positioning system, the mainstream method was generally to use US GPS (Global Positioning System) satellites. For example, there is a known method of measuring the displacement of a structure by relative positioning between a GPS receiver installed at a fixed point on the ground around the structure and a GPS receiver installed at an observation point on the structure. (see Patent Documents 1 and 2, for example). However, the number of GPS satellites in the United States is also limited, and there are the following restrictions and problems when using them.

(1) In order to capture the GPS satellites necessary for positioning analysis, it is necessary to keep the elevation angle from the satellite positioning device at 15° or more.
(2) Therefore, in urban areas where it is difficult to secure a view of the sky due to overcrowded structures, the installation location of the satellite positioning device is limited to the roof of the structure. In other words, it is only possible to measure the displacement around the roof of a structure or the like.
(3) However, since various facilities are installed on the roof, the installation location of the satellite positioning equipment is limited.
(4) Even if a satellite positioning device can be installed on the roof, there is a risk that it will be affected by multipaths of other equipment on the roof and surrounding buildings, preventing accurate displacement measurement.

Conventionally, due to these problems, no attention has been paid to wall surface positioning of structures and the like.

On the other hand, regarding positioning technology using GPS satellites, a technology as shown in Patent Document 3 is known. This technique discriminates satellite signals affected by multipath in a simple and reliable manner and corrects the measured position of the mobile station.

By the way, currently, not only the GPS satellites of the United States, but also the satellite positioning systems of Russia, Europe, China, and Japan (hereinafter, all of these are collectively referred to as GNSS (Global Navigation Satellite System)) are in operation. It is possible to receive signals from around 30 GNSS satellites by positioning with a satellite positioning device. It is expected that the number of GNSS satellites in each country will increase in the future, and the increase in the number of quasi-zenith satellites in Japan will make it easier to acquire signals from high elevation angles. It is often thought that the above problems can be easily solved as the number of satellites increases, but conversely, the problem of multipath increase also arises as the number of satellites increases.

As a technique for solving these problems, some of the inventors of the present invention have already proposed a technique as shown in Patent Document 4. This technique has the following functions. According to this, it is possible to accurately measure the displacement of the observation point installed on the wall of the structure, etc., so it is suitable for monitoring the displacement, deformation, etc. of the roof and sides of the structure installed in an overcrowded environment. .
(1) Function to select GNSS satellite signals (2) Function to determine ambiguity, which is the key to RTK positioning, with high reliability (3) Function to retain ambiguity (4) Output from GNSS receiver A function that uses cycle slip information, etc. of the carrier wave phase

A supplementary explanation of the above function (3) will be given. Ambiguity retention means that once the correct ambiguity is determined for a satellite that does not have a cycle slip or the like, RTK positioning can theoretically continue even if that value is retained. Ambiguity retention utilizes this feature. The feature of this method is that even in the case where the ambiguity holding is interrupted in the conventional method, the interruption can be eliminated as much as possible, and the recovery after the interruption can be performed quickly. As one example, ambiguity determination requires a dual phase difference due to master and slave satellites. Ambiguity retention is no longer possible when the primary satellite is changed. In order to respond to such events, it is a function that selects a good quality main satellite in advance and has the ability to instantly maintain ambiguity with another main satellite even if the main satellite is changed.

Since RTK positioning is relative positioning between a reference point and an observation point, a double phase difference is used for calculation. The double phase difference is obtained by simultaneously receiving the carrier wave phase from the same satellite with two receivers, obtaining the single phase difference of both received data for each of the two satellites in units of one cycle, and calculating the difference between the two single phase differences. is obtained by taking By using this dual phase difference, cancellation of satellite and receiver clock errors is possible. In RTK positioning, three or more sets of combinations for obtaining this double phase difference are created, and using the positioning data of many times, the least squares method is used to calculate the integer wavelengths of each channel of the receiver between each satellite and the receiver. A baseline vector (three-dimensional coordinate difference) is determined by estimating an uncertain factor (integer value bias).

When RTK positioning is performed using different types of satellites, various biases to be considered occur because the used frequencies and the like differ for each type of satellite. In order to avoid the influence of these biases, in RTK positioning, the mainstream is mixed positioning in which a double phase difference is obtained separately for each type of satellite positioning system. For mixed positioning analysis, at least two satellites of the same type are always required (for example, a primary satellite and a secondary satellite), and the satellite with the highest elevation angle visible from the receiver is adopted as the primary satellite. Satellites with only one visible satellite are not used for analysis in the first place.

For example, if the main satellite is a GPS satellite, the secondary satellite also selects a GPS satellite, if the primary satellite is a quasi-zenith satellite, the secondary satellite also selects a quasi-zenith satellite, and the double phase difference is calculated for the selected pair. Here, it is assumed that there are two GPS satellites, two quasi-zenith satellites, two Galileo satellites, and two Glonass satellites in the sky. Since there are two satellites of different types each, the satellite near the zenith is regarded as the primary satellite, and the satellite located away from the zenith is regarded as the secondary satellite, and the double phase difference is calculated. In this case, an appropriate ambiguity is calculated from the double phase difference calculated with the GPS satellite pair, the quasi-zenith satellite pair, the Galileo satellite pair, and the Glonass satellite pair. This mixed positioning uses the dual phase differences of many satellite constellations to improve the positioning accuracy.

JP 2015-197344 A JP 2008-76117 A Japanese Patent No. 5232994 Japanese Patent Application No. 2017-079210 (Unpublished at this time)

In the case of an open sky with no obstacles in the sky, all types of satellites are well positioned in the sky at any time of day, so the double phase difference of each constellation is easily calculated, and even mixed positioning Accurate calculation is possible. However, when positioning observation points such as the outer wall of a building in an overcrowded environment or the slope of the left or right bank of a dam, the sky field of view is relatively narrow, so the number of satellites of the same type in the sky is limited to two or less. can be. Even if there seems to be a lot of positioning satellites in the sky, the calculation of the double phase difference of some constellations becomes difficult, and as a result, there is a possibility that the accuracy of the mixed positioning is lowered.

In addition, the relatively narrow field of view limits the hours during which two or more satellites of the same type are in the sky. For example, even if there are seven satellites in the sky, it is often possible that there is only one satellite of a certain type. If the breakdown of these 7 satellites is 2 GPS satellites, 1 quasi-zenith satellite, 2 Galileo satellites, 1 Glonass satellite, and 1 BeiDou satellite, then only GPS satellites can calculate the double phase difference with conventional positioning analysis and Galileo satellites alone, and there is a risk that the positioning accuracy will be degraded.

In addition, since the quasi-zenith satellites have specifications that conform to the GPS satellites, if the number of GPS satellites is reduced and there are multiple quasi-zenith satellites (three or more in total if the environment is good), the maximum elevation angle will be A double phase difference can be calculated with a certain GPS satellite or quasi-zenith satellite as the primary satellite and the others as secondary satellites. However, since this state rarely continues for a long time on the outer wall of the building, the left bank of the dam, or the like, it is difficult to measure the position continuously for 24 hours.

In order to deal with such a problem, the present inventor conducted various studies focusing on the system bias between satellites, especially the clock difference between satellites. As described above, since there is no clock difference between the GPS satellite and the quasi-zenith satellite, the combination of the GPS satellite and the quasi-zenith satellite as the primary satellite and the other GPS satellites and the quasi-zenith satellite as the secondary satellites will create a double phase difference. can be calculated. However, since GPS satellites, quasi-zenith satellites, and other types of satellites have clock differences, other types of satellites need to calculate the double phase difference for each satellite type.

As a result of repeated acquisition of various positioning data and modifications and trials of the positioning analysis algorithm, the present inventor has arrived at the following invention, which can improve the positioning accuracy more than the above-mentioned conventional patent document 4. In other words, by eliminating the system bias (satellite clock difference) between satellites in advance on the algorithm, we can use as many satellites in the sky as possible and create many duplicates with one as the main satellite and the other as the slave satellite. A phase difference can be acquired, and as a result, the present invention described below can be achieved to improve positioning accuracy.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a displacement measuring method and a displacement measuring system with improved positioning accuracy.

In order to solve the above-described problems and achieve the object, a displacement measurement method according to the present invention uses a satellite signal receiver that receives satellite signals from positioning satellites of a plurality of different satellite positioning systems to measure a structure or the like. A method for measuring the displacement of a relatively stable object including: an observation point consisting of a satellite signal receiver installed on the outer surface of said object; and a satellite signal receiver installed at a location other than the outer surface of said object. A relative positioning step of obtaining a displacement over time with a fixed point configured by relative positioning, wherein the relative positioning step includes a positioning satellite at the highest elevation angle from the satellite signal receiver among a plurality of positioning satellites is selected as the primary satellite, a positioning satellite other than this positioning satellite is selected as the secondary satellite, and the selected primary satellite and secondary satellites are regarded as positioning satellites of the same satellite positioning system, thereby eliminating the bias between different satellite positioning systems. relative positioning based on the dual phase difference calculated using the satellite signals of the master satellite and the slave satellite.

Further, the displacement measurement system according to the present invention measures the displacement of a relatively stable object including structures using a satellite signal receiver that receives satellite signals from positioning satellites of a plurality of different satellite positioning systems. A system in which the passage of time between an observation point composed of a satellite signal receiver installed on the outer surface of said object and a fixed point composed of a satellite signal receiver installed at a location other than the outer surface of said object. Relative positioning means for obtaining displacement due to relative positioning by relative positioning, wherein the relative positioning means selects a positioning satellite at the highest elevation angle from the satellite signal receiver from among the plurality of positioning satellites as a main satellite, and selects other than this positioning satellite positioning satellites are selected as secondary satellites, and the selected primary and secondary satellites are regarded as positioning satellites of the same satellite positioning system to eliminate the bias between different satellite positioning systems, and the satellite signals of the primary and secondary satellites are relative positioning is performed based on the double phase difference calculated using the

According to the displacement measurement method of the present invention, the displacement of a relatively stable object including structures is measured using a satellite signal receiver that receives satellite signals from positioning satellites of a plurality of different satellite positioning systems. A method wherein the time lapse between an observation point consisting of a satellite signal receiver mounted on the outer surface of said object and a fixed point consisting of a satellite signal receiver mounted at a location other than the outer surface of said object. A relative positioning step of acquiring the displacement associated with the relative positioning by relative positioning. positioning satellites are selected as secondary satellites, and the selected primary and secondary satellites are regarded as positioning satellites of the same satellite positioning system to eliminate the bias between different satellite positioning systems, and the satellite signals of the primary and secondary satellites are Since relative positioning is performed based on the double phase difference calculated using this method, it is possible to accurately measure the displacement of the observation point installed on the outer surface of a relatively stable object including structures. For this reason, the present invention is suitable for monitoring displacement, deformation, etc., not only on the top (rooftop) of relatively stable objects, including structures installed in dense environments, but also on the sides (wall surfaces). preferred.

Further, according to the displacement measurement system according to the present invention, a satellite signal receiver that receives satellite signals from positioning satellites of a plurality of different satellite positioning systems is used to measure relatively stable displacements of objects including structures. A measurement system between an observation point consisting of a satellite signal receiver installed on the outer surface of said object and a fixed point consisting of a satellite signal receiver installed at a location other than the outer surface of said object. Relative positioning means for obtaining displacement over time by relative positioning, wherein the relative positioning means selects a positioning satellite at the highest elevation angle from the satellite signal receiver from among the plurality of positioning satellites as a main satellite, and this positioning Selecting a positioning satellite other than a satellite as a secondary satellite, and considering the selected primary and secondary satellites as positioning satellites of the same satellite positioning system to eliminate the bias between different satellite positioning systems, and to eliminate the bias between the primary and secondary satellites Since relative positioning is performed based on the double phase difference calculated using the signal, it is possible to accurately measure the displacement of the observation point installed on the outer surface of a relatively stable object including structures. . For this reason, the present invention is suitable for monitoring displacement, deformation, etc., not only on the top (rooftop) of relatively stable objects, including structures installed in dense environments, but also on the sides (wall surfaces). preferred.

FIG. 1 is a schematic diagram showing an embodiment of a displacement measuring method and a displacement measuring system according to the present invention. FIG. 2 is a schematic configuration diagram showing an embodiment of a displacement measuring system according to the present invention. FIG. 3 is a schematic flow chart diagram showing an embodiment of a displacement measuring method according to the present invention. 4A and 4B are diagrams showing the aerial field of view of the observation point as viewed with a fish-eye camera, where (1) is the aerial field of view of the observation point 1 and (2) is the aerial field of view of the observation point 2. FIG. FIG. 5 is a diagram showing the RTK positioning result of observation point 1. As shown in FIG. FIG. 6 is a diagram showing the RTK positioning result of the observation point 2. As shown in FIG.

As described above, the present inventors obtained various positioning data, modified and analyzed the algorithm, and as a result, arrived at the present invention that can improve the positioning accuracy more than the conventional Patent Document 4. By applying the present invention, it is possible to use data from, for example, only one Galileo satellite in the sky. improve markedly.

EMBODIMENT OF THE INVENTION Below, embodiment of the displacement measuring method and displacement measuring system based on this invention is described in detail based on drawing. In the following description, wall surface positioning of a small and medium-sized apartment installed in a densely populated urban environment will be described as an example of a structure whose displacement is to be measured and monitored. However, the present invention is limited by this embodiment. not a thing It should be noted that the present invention can be used not only for wall positioning of relatively stable stationary objects including structures, but also for satellite positioning equipment such as roof positioning of relatively stable stationary objects including structures. It can also be applied to positioning when there are obstacles that cause multipath around the installation location.

A displacement measurement method according to an embodiment of the present invention measures the displacement of a structure using a GNSS positioning device (satellite signal receiver) that receives satellite signals from GNSS satellites (positioning satellites) of a plurality of different satellite positioning systems. It is a method of measurement. In this embodiment, the time between the observation point configured by the GNSS positioning device installed on the outer wall surface of the structure and the fixed point configured by the GNSS positioning device installed on the outer wall surface of the structure It includes a relative positioning step of acquiring displacement over time by relative positioning.

In the relative positioning step, the GNSS satellite having the highest elevation angle from the GNSS positioning device among the plurality of GNSS satellites is selected as the main satellite, the GNSS satellites other than this satellite are selected as the secondary satellites, and the selected primary satellite and the secondary satellites are selected. are regarded as satellites of the same satellite positioning system, thereby removing the bias between different satellite positioning systems and performing relative positioning based on the double phase difference calculated using the satellite signals of the primary and secondary satellites. Here, a method using interferometric positioning using a carrier wave, which has the highest accuracy among relative positioning methods, will be described.

First, after determining the coordinates of the fixed point at the initial stage of installation of the GNSS positioning equipment, observation is performed simultaneously with the GNSS positioning equipment at all fixed points and observation points, and the difference in radio wave arrival from the satellite (single phase difference), double Analyze the phase difference and find the distance between the fixed point and the observation point. For example, when 5 GNSS positioning devices are installed, when a fixed point and other observation points are counted as 1 set, by acquiring 5 sets of coordinate changes and baseline length changes, it is possible to determine which part of the structure It is possible to grasp whether there is inclination or subsidence.

Next, taking as an example a displacement measurement system in which five GNSS positioning devices (observation points) are installed, the flow from initial coordinate setting to observation will be described.

As shown in FIG. 1, five GNSS positioning devices A to E for receiving satellite signals from satellites are installed at different positions on the outer wall surface 2 of a structure 1 such as a small and medium-sized apartment building as observation points. One GNSS positioning device is installed on the structure 4 of , and interferometric positioning is performed as a fixed point F. The example in FIG. 1 shows the case where GNSS positioning devices A to E are installed at a total of five locations, the four corners of the top, bottom, left, right, and center of the outer wall surface 2 facing the road. However, any position and number may be used as long as they are one point for the same structure or a plurality of points different from each other. As shown in FIG. 1, the fixed point F may be set on a place other than the outer wall surface 2, for example, it may be set on the surrounding ground of the structure 1 or on the roof of another structure 3 or the like.

GNSS positioning equipment installed at observation points and fixed points may be either high-performance dual-frequency GNSS equipment or inexpensive single-frequency GNSS equipment. It is assumed that the GNSS positioning devices A to E are connected to a computer in a remote measurement room via a wired or wireless communication line through a communication device (not shown).

FIG. 2 is a schematic configuration diagram of the displacement measurement system 10 according to the present invention. As shown in this figure, this displacement measurement system 10 has a computer 12 provided in a measurement room. The computer 12 comprises relative positioning means 14, notification means 16, warning means 18, storage means 20, and control means 22 for controlling these. The storage means 20 stores and collects measurement data obtained from the GNSS positioning devices A to E in real time. The data stored and collected in the storage means 20 are appropriately read out through the control means 22 and processed by the relative positioning means 14 . The relative positioning means 14 acquires displacement/deformation information over time between the GNSS positioning devices A to E by relative positioning, and is composed of various kinds of analysis software, calculation means, and the like. This computer 12 is connected to the Internet. For this reason, for example, at the request of the user, the displacement of the structure acquired by the user terminal device (for example, personal computer, mobile phone terminal, etc.) owned by the person involved in the management of the structure via the Internet by the function of the notification means 16・Deformation information can be distributed. In addition, the alarm means 18 performs a process of issuing an alarm such as an alarm sound through the computer 12 in the control room or the above-described user terminal device when a displacement equal to or greater than a predetermined threshold is acquired.

As shown in FIG. 3, first, GNSS positioning devices A to E are installed at five observation points (step S1). Next, the initial coordinates of the fixed point F set on the structure 4 are determined by independent positioning for several hours to several days, static positioning with the surrounding electronic control points, or the like (step S2).

Next, observation is started simultaneously at the fixed point and the observation point, and the difference (single phase difference) and double phase difference in radio wave arrival from the satellite are analyzed to obtain the distance between the fixed point and the observation point (step S3). The above initial coordinate setting and interferometric positioning can be performed by analysis software and interferometric positioning means (not shown) provided in the computer 12 in the measurement room. In this embodiment, real-time kinematic (RTK) positioning is used as relative positioning. At that time, an algorithm, which will be described later, is applied to obtain an appropriate coordinate/baseline length solution for the outer wall surface 2 of the structure 1 .

The displacement/deformation information as the observation result including the abnormal value is reported to the computer 12 in the measurement room, the screen of the user terminal device, etc. by the function of the reporting means 16 (step S4). Here, when the acquired abnormal value is equal to or greater than a predetermined threshold value, the alarm means 18 issues an alarm such as an alarm sound through the computer 12 in the measurement room or the user terminal device. This allows a user such as an administrator or a person concerned with management to immediately recognize that a displacement equal to or greater than the threshold has occurred.

In the above embodiment, the computer 12 can acquire the positioning information of the observation points (also fixed points) in real time, and the analysis by the relative positioning means 14 is also possible in real time. Further, the notification means 16 can also notify the user of the analysis results (observation results), for example, at predetermined time intervals (for example, every day (24 hours)) in response to the user's request. Therefore, the analysis time required when five observation points are provided is basically real time. In addition, since structures generally do not undergo large displacements, it is customary to compare the average value of positioning information obtained by averaging several hours or one day, except in the event of a major earthquake.

According to the present embodiment, for example, deformation/displacement of piles and structures, slopes, and dam slopes of public facilities such as schools installed in overcrowded environments such as urban areas, small and medium-sized condominiums without builders, etc. departments can be monitored. Public facilities are generally used as evacuation sites, but the present invention can also be used when confirming whether or not the facilities are safe while aftershocks continue after a major earthquake.

<Algorithm>
Next, an algorithm used in the above RTK positioning (relative positioning) will be described.

This algorithm selects the GNSS satellite with the highest elevation angle from the GNSS positioning equipment as the main satellite from among the plurality of GNSS satellites, selects the GNSS satellites other than this satellite as the secondary satellite, and selects the selected primary satellite and the secondary satellite. It is intended to remove the bias between different satellite navigation systems by regarding them as satellites of the same satellite navigation system, and to perform relative positioning based on the double phase difference calculated using the satellite signals of the primary and secondary satellites. .

In this algorithm, in the RTK positioning calculation process, different types of GNSS satellites such as GPS, Quasi-Zenith (QZSS), Galileo, etc. are treated as GNSS satellites of the same type (on the satellite positioning system) and the double phase difference is calculated. . More specifically, the double phase difference is calculated with the GNSS satellite at the highest elevation angle among the satellites receivable from the GNSS positioning equipment as the primary satellite and all the other GNSS satellites as secondary satellites. Subsequent positioning analysis uses this double phase difference.

Thus, instead of calculating the double phase difference for pairs of satellites of the same type, all satellites in the sky view of the GNSS positioning instrument are utilized to calculate the double phase difference. As a result, regardless of the type of satellite, by forming a pair with the one near the zenith as the master satellite and all the other satellites as slave satellites, it is possible to use even a single satellite in the sky to achieve a double phase difference. can be calculated, and the ambiguities are calculated more accurately, resulting in improved positioning accuracy.

For example, assume that there are four GPS satellites, one quasi-zenith satellite, three Galileo satellites, and four BeiDou satellites in the sky view of the GNSS positioning instrument. In the conventional method, four dual phase differences can be obtained from a total of five GPS satellites and quasi-zenith satellites, with the one with the highest elevation angle being the primary satellite and the other four satellites being secondary satellites. From the three Galileo satellites, one with the highest elevation angle is the main satellite and the other two are the secondary satellites, and two dual phase differences can be obtained. From the four BeiDou satellites, three dual phase differences can be obtained with the one with the highest elevation angle as the main satellite and the other three satellites as slave satellites. Therefore, a total of 9 (=4+2+3) double phase differences can be obtained with the conventional method. However, it is necessary to have an environment in which the double phase difference can be calculated for each satellite constellation. On the other hand, in the method of the present invention, from all 12 positioning satellites (=4+1+3+4), a total of 11 double phase differences can be obtained with one satellite having the highest elevation angle as the primary satellite and the other 11 satellites as secondary satellites. Thus, according to the present invention, since more double phase differences can be obtained than the conventional method, ambiguities are calculated more accurately, resulting in improved positioning accuracy.

<Verification of effects of the present invention>
Next, positioning experiments conducted to verify the effects of the present invention will be described. In this experiment, an observation point 1 and an observation point 2 were provided at different locations on the wall surface of an existing building, and the positioning analysis was performed using the above algorithm. This is a comparison of the results. Both positioning analyzes were performed using 23 hours 1 Hz (82800 seconds worth of data) in the time zone from 3:30 UTC on November 15, 2017 to 2:30 UTC on 16 November. In addition, as different types of satellite positioning systems, GPS satellites, QZSS satellites, BeiDou satellites, and Galileo satellite positioning systems were used, and seven or more satellites from these systems were used. FIG. 4(1) shows a photograph of the sky view of observation point 1, and FIG. 4(2) shows a photograph of the sky view of observation point 2. In FIG. Both sky fields are narrow.

FIG. 5 shows the positioning result of observation point 1, and FIG. 6 shows the positioning result of observation point 2. As shown in FIG. In each figure, (1) is a plot of the results in the horizontal direction, (2) is a comparison of the results, (3) is the time-series transition in the latitudinal direction, (4) is the time-series transition in the longitudinal direction, and (5) is the height It is a time-series transition in the downward direction.

As shown in these figures, as a result of analyzing the positioning data using the algorithm of the present embodiment, the Fix rate (reliability (within horizontal ± 10 cm)) of observation point 1 increased from 99.93% to 100% in the comparative example. %, it was confirmed that the observation point 2 improved from 65.28% of the comparative example to 98.89%. Furthermore, the large jump in position that sometimes appears during the positioning time has also been eliminated.

As described above, according to the displacement measuring method according to the present invention, a relatively stable displacement including structures and the like is performed using a satellite signal receiver that receives satellite signals from positioning satellites of a plurality of different satellite positioning systems. A method for measuring the displacement of an object, comprising an observation point composed of a satellite signal receiver installed on the outer surface of said object and a fixed point composed of a satellite signal receiver installed at a location other than the outer surface of said object. A relative positioning step of acquiring a displacement over time between and by relative positioning, wherein the relative positioning step selects the positioning satellite at the highest elevation angle from the satellite signal receiver among the plurality of positioning satellites as the main satellite In addition, a positioning satellite other than this positioning satellite is selected as a subsatellite, and the selected main satellite and subsatellite are regarded as positioning satellites of the same satellite positioning system, thereby removing the bias between different satellite positioning systems. Since relative positioning is performed based on the double phase difference calculated using satellite signals from secondary satellites, it is possible to accurately measure the displacement of observation points installed on the outer surface of relatively stable objects, including structures. .

Further, according to the displacement measurement system according to the present invention, a satellite signal receiver that receives satellite signals from positioning satellites of a plurality of different satellite positioning systems is used to measure relatively stable displacements of objects including structures. A measurement system between an observation point consisting of a satellite signal receiver installed on the outer surface of said object and a fixed point consisting of a satellite signal receiver installed at a location other than the outer surface of said object. Relative positioning means for obtaining displacement over time by relative positioning, wherein the relative positioning means selects a positioning satellite at the highest elevation angle from the satellite signal receiver from among the plurality of positioning satellites as a main satellite, and this positioning Selecting a positioning satellite other than a satellite as a secondary satellite, and considering the selected primary and secondary satellites as positioning satellites of the same satellite positioning system to eliminate the bias between different satellite positioning systems, and to eliminate the bias between the primary and secondary satellites Since relative positioning is performed based on the double phase difference calculated using the signal, the displacement of the observation point installed on the outer surface of a relatively stable object including structures can be accurately measured.

As described above, the displacement measuring method and displacement measuring system according to the present invention are useful for displacement monitoring of objects such as structures using a plurality of different satellite positioning systems, especially in dense environments such as urban areas. It is suitable for monitoring the displacement of walls of installed structures, etc., and for monitoring displacement by installing satellite positioning equipment on rooftops where there are obstacles that cause multipath.

1, 4 structure 2 outer wall surface (outer surface)
3 Rooftop (outer surface)
10 displacement measurement system 12 computer 14 relative positioning means 16 notification means 18 alarm means 20 storage means 22 control means A to E GNSS observation points (positioning equipment)
F GNSS fixed point

Claims (2)

A method of measuring the displacement of a relatively stable object including a structure with a limited sky view using a satellite signal receiver that receives satellite signals from positioning satellites of a plurality of different satellite positioning systems,
Displacement over time between an observation point configured by the satellite signal receiver installed on the outer surface of the object and a fixed point configured by the satellite signal receiver installed at a location different from the object , with relative positioning steps obtained by relative positioning,
The relative positioning step selects, as a main satellite, the positioning satellite located at the highest elevation angle position from the satellite signal receiver from among the plurality of positioning satellites receivable by the satellite signal receiver, and the positioning satellite in the sky field of view of the satellite signal receiver by selecting, as a secondary satellite, the positioning satellite that is not at the highest elevation position from the satellite signal receiver, and regarding the selected primary satellite and the secondary satellite as the positioning satellite of the same satellite positioning system ; A displacement measurement method comprising calculating a double phase difference using all satellites and performing relative positioning based on the calculated double phase difference. A system for measuring the displacement of a relatively stable object including a structure with a limited sky view using a satellite signal receiver that receives satellite signals from positioning satellites of a plurality of different satellite positioning systems,
Displacement over time between an observation point configured by the satellite signal receiver installed on the outer surface of the object and a fixed point configured by the satellite signal receiver installed at a location different from the object , comprising relative positioning means obtained by relative positioning,
The relative positioning means selects, as a main satellite, the positioning satellite located at the highest elevation angle position from the satellite signal receiver from among the plurality of positioning satellites receivable by the satellite signal receiver, and the satellite signal receiver the positioning satellite in the sky view of the satellite signal receiver by selecting, as a secondary satellite, the positioning satellite that is not at the position of the highest elevation angle from the satellite signal receiver, and regarding the selected primary satellite and the secondary satellite as the positioning satellite of the same satellite positioning system ; A displacement measurement system characterized by calculating a double phase difference using all satellites and performing relative positioning based on the calculated double phase difference.

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