JP3127220B2 - Positioning method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning method for receiving a signal transmitted from a positioning satellite such as a GPS satellite and performing positioning.

[0002]

2. Description of the Related Art In a positioning method using a GPS signal transmitted from a GPS satellite, error factors include satellite clock error, satellite orbit error, ionospheric and tropospheric delay error, receiver noise, multipath, and selection availability. (SA), user equivalent distance error, user position accuracy, and the like. By performing relative positioning for observing the difference in distance from the satellite at the two observation points, the clock error of the satellite, the orbital error of the satellite, and the like are cancelled, and the ionospheric and tropospheric delay errors are L1 band and L
Correction can be made by observing two bands simultaneously.

[0003]

On the other hand, multipath is
This is an error caused by a GPS signal reflected by some kind of shield such as a mountain or sea surface, which is incident together with a direct wave. When this is large, it may cause an error of several meters, and high-precision observation is performed. Because it was an obstacle. However, in multipath, if the position of the antenna changes even slightly, the situation will be completely different.
Observation at the point and subtracting it could not eliminate it.

In order to prevent the influence of multipath, there are measures such as selecting an observation position and limiting observation satellites to those having a high elevation angle. However, this is not limited to the case where observation conditions can always be satisfied. In order to reduce multipath errors, observations were taken for a long time, the position of the satellite was moved, and multipath conditions were changed and averaged to cancel. However, this method has a problem that observation takes time.

In GPS positioning, it is a condition that an antenna is installed at an observation point. However, there are places where it is impossible or difficult to install the antenna, such as a steep slope or a space between trees. Efforts were made to raise an extremely high tower and install an antenna on it.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a positioning method capable of eliminating an error due to multipath in a short time of observation and enabling observation even when a GPS receiver cannot be installed at an observation point. .

[0007]

The invention of claim 1 of the present application is a positioning method for measuring a distance or an azimuth from a first observation point to a second observation point, wherein the second observation point In the vicinity, a plurality of auxiliary points each having a known auxiliary vector indicating the distance and direction to the second observation point are set, and a positioning receiver is provided at each of the first observation point and the plurality of auxiliary points.
The plurality of positioning receivers are operated in the same time zone to collect data, and the first observation point and the respective data are collected using the data collected at the first observation point and the data collected at the auxiliary points. A plurality of temporary baseline vectors from the first observation point to the second observation point are obtained by obtaining an auxiliary baseline vector indicating a baseline vector between the auxiliary points and adding the auxiliary vector to the auxiliary baseline vector. The method is characterized by averaging all or a part of the plurality of temporary baseline vectors obtained in the above, and determining a baseline vector from the first observation point to the second observation point.

According to the invention of claim 2 of the present application, a plurality of auxiliary points having known auxiliary vectors indicating the distance and direction to the observation point are set in the vicinity of the observation point, and at each of the auxiliary points, a positioning satellite is used. Positioning, determining a plurality of candidates for the position of the observation point by adding the auxiliary vector from the positioning result, and averaging all or a part of the candidates to determine the position of the observation point. And

[0009] The invention of claim 1 relates to relative positioning between a first observation point and a second observation point. A positioning receiver is provided at the first observation point, and the second observation point is provided. about,
A plurality of auxiliary points are set in the vicinity thereof, and a positioning receiver is provided at the auxiliary points. The azimuth and distance (auxiliary vector) between this auxiliary point and the second observation point are measured in advance and are known. It is assumed that the auxiliary point may include the second observation point itself. In any case, a plurality of positioning receivers are provided for the second observation point. Data is collected by operating these positioning receivers simultaneously in the same time zone. Then, using the collected data,
A base line vector (auxiliary base line vector) between the observation point and the auxiliary point of the second observation point is obtained. The auxiliary base line vector may be calculated by a conventional relative positioning calculation. The auxiliary vector is added to the auxiliary baseline vector to obtain a temporary baseline vector which is determined as a base vector between the first observation point and the second observation point. This temporary base line vector is obtained by the number of auxiliary points set for the second observation point. Although these temporary baseline vectors include errors affected by multipaths occurring at the corresponding auxiliary points, the state of the multipath is considered to be completely different for each auxiliary point, and these are averaged. Thus, this error can be canceled. Accordingly, it is not necessary to wait for a change in the state of the multipath caused by the movement of the positioning satellite after long-time observation, and accurate relative positioning can be performed with short-time observation.

[0010] Even when a positioning receiver (antenna) cannot be installed at the second observation point, an antenna can be installed in a place where it can be installed around the second observation point, and observation can be performed. By installing a positioning receiver at a location, it is possible to compensate for an error generation factor that a receiver cannot be installed at the observation point itself.

The invention according to claim 2 is applicable to both independent positioning and relative positioning. A plurality of auxiliary points are set near an observation point, and a positioning receiver is provided at the auxiliary point. The azimuth and distance (auxiliary vector) between the auxiliary point and the observation point are measured in advance and are known. Note that the observation point itself may be included in this auxiliary point. In any case, positioning is performed by providing positioning receivers at a plurality of points. Data is collected by operating these positioning receivers simultaneously in the same time zone. In the case of relative positioning,
The positioning receiver at the observation point of the other party is also operated at the same time to collect data.

The position of each auxiliary point is determined based on the collected data, and a candidate for the position of the observation point is obtained based on this position and the auxiliary vector. This candidate is obtained by the number of auxiliary points. Each of these candidates contains an error affected by the multipath occurring at the corresponding auxiliary point, but the state of the multipath is considered to be completely different for each auxiliary point, and by averaging them, , This error can be canceled. This eliminates the need to wait for a change in the state of the multipath caused by the movement of the positioning satellite after long-time observation, and accurate positioning can be performed by short-time observation.

It should be noted that, when the invention of claim 1 and the invention of claim 2 are combined, in the case of relative positioning, setting of an auxiliary point to both of two observation points is included. The number of auxiliary baseline vectors to be obtained is obtained by the number of first auxiliary points × the number of second auxiliary points.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an installation form of a GPS receiver in a surveying scene to which a relative positioning method according to the present invention is applied. This figure shows a scene of a survey for obtaining a base line vector between the observation point A and the observation point B. Observation point A,
When obtaining a baseline vector between the observation points B, generally, a GPS receiver is installed at the observation points A and B to perform relative positioning. In the case where the influence of multipath is large, multiple GPS receivers are installed at auxiliary points around these observation points, and different multipaths generated at each auxiliary point are combined and averaged to cancel this. I am trying to do it. In addition, when the observation points A and B are places where it is impossible or extremely difficult to install the GPS receiver, such as a place covered with tall trees, a steep slope, or the like, a place deviating from the observation points in this way. The surveying is enabled by setting an auxiliary point on the GPS receiver and installing a GPS receiver. In any case, it is assumed that the azimuth and distance (auxiliary vector) between the observation point and the auxiliary point have been measured in advance and are known.

In this figure, auxiliary points A1 and A
2, A3 are provided, and auxiliary points B1, B2,
B3 are provided, and each has a GPS receiver. The distance / azimuth (auxiliary vector) between the observation point A and the auxiliary points A1, A2, A3 and the distance / azimuth (auxiliary vector) between the observation point B and the auxiliary points B1, B2, B3 are determined in advance. , And these are referred to as auxiliary vectors a1, a2, a3, b1, b, respectively.
2, b3. Since the distance between the observation point and the auxiliary point is in the range of several meters to about 100 meters, this measurement may be performed using a tape measure or general optical measurement. In this figure, the GPS receivers are not provided at the observation points A and B. However, unless the installation is impossible or difficult, the GPS receivers may be installed at the observation points without any problem.

FIG. 2 is a functional block diagram of the GPS receiver installed at the auxiliary point. In the above-described surveying scene, all the GPS receivers need to receive the GPS signal in the same time zone and perform integration of the carrier wave phase shift value. The GPS receiver 1 analyzes the signal input from the antenna 2 receiving the GPS signal,
A GPS receiving unit 3 for extracting the PS signal, a data recording unit 4 for recording the GPS signal extracted by the GPS receiving unit 3,
A recording control unit 5 that controls the GPS receiving unit 3 and the data recording unit 4 according to data collection conditions such as the signal state and arrangement of the S satellite, and the recording control unit 5
The operation unit 6 is used to set satellite conditions (data collection conditions) necessary for recording PS data.

The GPS receiver 3 has 8 to 16 reception channels, and can simultaneously capture and receive the same number of GPS signals as the number of channels. The operation unit 6 can set the following data collection conditions for the recording control unit 5. The contents described in the right column of each condition are standard values of the condition.

Elevation angle of satellite 15 degrees or more Number of necessary satellites 5 or more PDOP 6 or less Duration of the above conditions 30 minutes or more Equipment installation time zone 9: 00-18: 00 The elevation angle of the satellite is the minimum elevation angle of the satellite required to receive a good signal with few error factors such as multipath. The required number of satellites is the minimum number of receiving satellites required for position determination and confirmation in relative positioning. P
DOP (Position Dilution Of)
Precision) is a rate of decrease in accuracy in performing three-dimensional positioning, and is determined by the positional relationship of the five or more satellites. The duration of the above condition is a minimum required duration of reception for averaging errors and removing integer biases due to satellite movement. The duration means a time during which the above conditions can be satisfied by the same combination of satellites. The device installation time zone is a time zone in which all GPS receivers installed at a plurality of auxiliary points can operate. This is because although the time zone in which the GPS receiver is installed and the power is turned on is shifted for each auxiliary point, all data in the same time zone are recorded in the data storage unit 4 having the same storage capacity. This is because it is necessary to make the operation time uniform in the GPS receiver.

The data recording section 4 may record data in a tape recording device or a semiconductor memory. As the semiconductor memory, a built-in memory, a detachable IC card, or the like can be used. In the figure, a removable IC is used as a recording medium.
The card 7 is used. With an IC card, recorded data can be transferred by inserting it into an IC card slot of the analyzer.

When the above device is installed at the auxiliary point in FIG.
Perform the following work for each device. First, the operation unit 6 is operated to set data collection conditions in the recording control unit 5. This condition is as described above, and the same condition is set for each device. Each device is transported to each auxiliary point and installed, and the power is turned on. After the observation time is over, it is withdrawn and the data recorded by each device is transferred to the analyzer 8. The analysis device 8 is usually a personal computer on which an analysis program operates.

GPS turned on at an auxiliary point
The receiver operates as follows. First, the GPS receiver 3 captures an arbitrary GPS signal that can be received, reads a navigation message from this signal, and inputs the navigation message to the recording controller 5. The recording control unit 5 calculates the orbit of each GPS satellite on the basis of the navigation message, judges the state of health, etc., and further calculates its own approximate position by independent positioning. Based on the activation, health status, and position of each of these GPS satellites, a “data recording time zone” that satisfies the data collection conditions set above is determined to create an observation schedule. Then, the GPS receiving unit 3 and the data recording unit 4 are put into a sleep state until the first data recording time zone arrives, thereby minimizing power consumption. Then, the GPS receiving unit 3 and the data recording unit 4 are activated for each data recording time zone, and the GPS data (integrated value of the carrier) received from a predetermined GPS satellite is recorded in the data recording unit 4. In this case, the GPS receiver 3 sometimes captures / receives a signal of a satellite that is not a recording target (for example, the elevation angle is less than 15 degrees), and the recording controller 5 transmits the data of such a satellite to the data recorder 4. Instruct not to record.

Further, even during the data recording time zone, the data collection condition may not be satisfied due to an accident that cannot be predicted by prior information based on a navigation message, for example, when a satellite to be recorded is out of order. The recording control unit 5 constantly monitors the signal received by the GPS receiving unit 3, and stops the data recording when the data collection condition is not satisfied due to an accident even during the data recording time zone. . If the state of the satellite deteriorates during the data recording time zone and the data collection conditions are no longer satisfied, the time during which the data was recorded is determined. If it is longer than 30 minutes, the data remains unchanged. If the recording time is less than 30 minutes, the data cannot be used and is discarded.

Each GPS receiver is installed at a distance of the auxiliary vector or the base line vector.
Since the conditions for GPS satellites above 0 km are almost the same, if the same data collection conditions are set for each GPS receiver, the same data is recorded based on the same determination. Therefore, it is possible to collect data under favorable conditions determined under the same data collection conditions without mutual communication.

The analyzing device 8 operates as follows. The data collected from a plurality of GPS receivers installed at the auxiliary point is fetched, and the auxiliary points A1,
By combining A2 and A3 with the auxiliary points B1, B2 and B3 on the observation point B side, nine auxiliary baseline vectors are determined. This auxiliary base line vector may be determined by using a conventional relative positioning analysis method. An analysis method is, for example, to obtain a double phase difference by synthesizing a phase difference between receivers and a phase difference between satellites. This is a method of removing an integer value bias based on the deformation over time. As described above, by collecting the GPS data at the same time, nine auxiliary baseline vectors can be calculated based on the six data. By such a method, nine auxiliary baseline vectors (A1 → B1) to (A
3 → B3). In these nine auxiliary baseline vectors,
Auxiliary vectors a1, a2, a3 measured in advance
b1, b2, and b3 are respectively added, and the provisional baseline vectors V11, V12, V13, and V2 of the observation point A and the observation point B are added.
1, V22, V23, V31, V32, and V33 are determined. Then, by averaging these temporary baseline vectors V11 to V33, a true baseline vector V in which errors such as multipath are canceled is determined.

In the averaging process, nine temporary base line vectors may be compared, and only the ones close to the true value may be averaged, excluding the ones greatly deviating from the others.

FIG. 3 is a detailed block diagram of the GPS receiver. The CPU 11 that controls the operation of the entire apparatus has R
The OM 12, the RAM 13, the internal interface 15, the clock circuit 16, the panel interface 18, and the IC card interface 19 are connected. The GPS signal receiving module 14 is connected to the internal interface 15. The panel interface 18 is connected to a key switch, a display, and the like of an operation panel. IC
The card interface 19 is connected to the data recording IC card 7.

The GPS signal receiving module 14 converts the signal from the GPS satellite received by the GPS antenna 2 into an intermediate frequency, and captures the GPS signal from the signal by synchronizing the C / A code pattern of each GPS satellite. The channels for capturing the GPS signals are provided in parallel with 8 to 16 channels, and 8 to 16 GPS signals can be captured simultaneously. GPS signal receiving module 1
4 sends a signal synchronized with the C / A code to the CPU 11 via the internal interface 15.

The CPU 11 reads the navigation message data from the signal synchronized with the C / A code phase, and
The orbit information of the PS satellite is determined. In addition, it is also possible to perform a single positioning with an accuracy of about 30 meters based on a GPS signal synchronized with four or more C / A codes. Further, during the data recording time period, the phase value of the carrier of the GPS signal to be recorded is integrated and written to the IC card 7 at regular intervals.

A program for controlling the above operation of the CPU 11 and the operation shown in the flowchart of FIG. RAM13 is the GPS
It is used as a work area when receiving a signal or recording data, and an area for storing the above-described data collection conditions is also set. The clock circuit 16 includes a reference oscillator, divides the reference oscillation signal to generate a clock signal, corrects an error based on a navigation message included in the GPS signal, and measures an accurate current time. The GPS data collection schedule progresses according to the time measured by the clock circuit. The operation panel 17 is provided with key switches for setting the data collection conditions described above. The IC card 7 connected to the IC card interface 19 has a storage capacity of about 1 MB,
The valid data in the recordable time zone is stored. This device is driven by a built-in or external battery.

FIG. 4 is a flowchart showing the operation of the GPS receiver. This flowchart shows the data collection operation of the device installed at the observation point. Before this operation is performed, the operation panel 17 is operated to operate the RAM 13.
It is assumed that data collection conditions have been set in. The staff installs the device at the observation point and turns on the power switch.

When the power switch is turned on (s1), first, a receivable GPS satellite signal is received (s1).
2) Read the navigation message from the received signal, calculate the orbit of the satellite, and perform independent positioning (s)
3). Since this sole positioning is only used to determine the satellites in the field of view and the satellites with an elevation angle of 15 degrees or more, 10
An accuracy of about 0 m is sufficient. The time zone (data recording time zone) that satisfies the set data collection conditions is calculated based on the own position determined by the single positioning and the orbit of the satellite determined by the navigation message.
This data recording time zone is not limited to one time within the apparatus installation time zone, and is often set a plurality of times with a time zone not suitable for data collection, and a schedule in which the data recording time zones are arranged is created. (S5). Thereafter, the GPS signal receiving module 14 is stopped until the data recording time zone approaches, and the digital circuit unit is set to the sleep state while leaving only the necessary minimum functions (s6). Thereby, the consumption of the battery can be minimized.

This sleep state is continued until 5 minutes before the start of the data recording time zone.
The whole function of the PS receiver is started (s10). Upon activation, the GPS signal receiving module 14 captures as many GPS signals as possible. In this state, the system waits until the recording start time is reached (s11). At the recording start time, unless the signal condition deteriorates in an unexpected situation (for example, a satellite failure), the signal of the selected satellite ( The carrier phase is written into the IC card 7 (s13). This is continued until the recordable time period ends or the memory of the IC card 7 becomes full (s14). When the data recording time period ends, the system waits in the sleep state until the next data recording time period arrives (s6).

On the other hand, if the signal condition deteriorates due to an unpredictable cause during the data recording and the data collection condition is no longer satisfied, the data recording up to this interruption in the present data recording time zone continues for 30 minutes or more. It is determined whether or not it is performed (s16). If it continues for 30 or more, this data can be used for analysis, so it is left as it is. If it is less than 30 minutes, this data cannot be used for analysis and is discarded (s1).
7). Then, until the remaining time of the current (currently suspended) data recording time zone becomes less than 30 minutes (s18),
It waits until the signal state recovers (s12). If the remaining time in the interrupted data recording time zone is less than 30 minutes, the process returns to s6 to put the device in the sleep state.

Then, if the memory of the IC card 7 is full (s14) or the schedule (all recordable time zones) is completed (s8), the operation is completed.

FIG. 5 is a flowchart showing the operation of the data analyzer 8. The IC card 7 is taken out of the GPS receiver having completed data collection, and is sequentially set in the data collection device 8. The data analyzer 8 takes in the collected data and stores it in the memory (s21). After that, auxiliary vectors a1, a2, a from the observation point to the auxiliary point
3, b1, b2, and b3 are input (s22). This auxiliary vector may be input from a keyboard or the like, or may be read from the IC card 7. Alternatively, the data may be input to the memory of the data analysis device 8 in advance. Then, 1 is set to the pointer i for specifying the auxiliary point on the observation point A side and the pointer j for specifying the auxiliary point on the observation point B side (s23, s24), and the auxiliary base line vector (Ai → Bj) is obtained by the above-described analysis method. Is determined (s25). Then, the auxiliary base vectors (Ai → Bj) and the auxiliary vectors ai and bj are added to calculate the temporary base line vector Vij (s26). The above operation is repeatedly executed until i and j reach the maximum values (i = 3, j = 3 in the example of FIG. 1) (s2
7 to s29). After calculating all temporary baseline vectors,
The true baseline vector V is calculated by averaging these temporary baseline vectors (s31).

By averaging the provisional baseline vectors obtained based on a plurality of auxiliary points in this manner, the GPS
Even if multipath occurs in the signal, multipath errors in completely different states are averaged out, so that this is canceled and an accurate baseline vector can be calculated.

The observation point is a GPS receiver (antenna).
Even in places where it is difficult to set up, by installing a GPS receiver in a place where it can be installed nearby and collecting data, surveying (positioning) of the observation point becomes possible, and The possibility of errors due to the absence of a GPS receiver can be eliminated by collecting data at a plurality of auxiliary points.

The present invention is not limited to the relative positioning,
It can also be applied to single positioning. For example, in the case of a ship, multipath due to sea surface reflection is a problem, but in addition to the bridge, receiving antennas are installed at the bow and stern, and multipath can be eliminated by performing positioning in parallel. become.

Further, the relative positioning can be applied not only to the case of fixed point observation such as surveying but also to the case of positioning while moving as in the case of kinematic positioning.
In this case, by providing a communication means in each GPS receiver, it is possible to perform almost real-time positioning.

In the above embodiment, the auxiliary points are set for both the observation points A and B. However, the auxiliary points are set to only one of them, and the GPS receiver is installed on the other point. It may be.

In the above-described embodiment, an example has been described in which a plurality of auxiliary points are set for one observation point and observation is performed at the same time. Can be applied to That is,
Land surveying surveys land boundaries to determine contours.
In conventional optical surveying, one contour line is measured at each corner of the boundary line, and the contour is determined by making a round. 3 of the present invention
By applying simultaneous observations of points or more, GPS receivers are installed at all corners of the land boundary, and observations are made simultaneously at the same time zone as shown in FIGS. By inputting this measurement result to the data analysis device 8 and analyzing it, the baseline vectors of all the boundary lines can be obtained at the same time,
Land boundaries can be determined with a single observation.

[0042]

As described above, according to the first aspect of the present invention,
By setting a plurality of auxiliary points at the second observation point, obtaining a plurality of temporary baseline vectors, and determining an averaged baseline vector, multipaths in different states are canceled by averaging. Thus, accurate positioning can be performed in a short time.

According to the second aspect of the present invention, a plurality of auxiliary points are set near the observation point to determine the position of each auxiliary point, and the position of the observation point is determined based on this position and the auxiliary vector. By obtaining candidates and averaging them to determine the position of the observation point, it becomes possible to cancel multipath and perform accurate positioning in a short time.

Both the first and second aspects of the present invention can be applied to positioning of a point where a positioning receiver cannot be installed on an observation point.

[Brief description of the drawings]

FIG. 1 is a diagram showing a surveying scene to which a positioning method according to the present invention is applied;

FIG. 2 is a functional block diagram of a GPS receiver used in the surveying scene.

FIG. 3 is a block diagram of the GPS receiver.

FIG. 4 is a flowchart showing the operation of the GPS receiver.

FIG. 5 is a flowchart showing the operation of the data analysis device used in the positioning method of the present invention.

[Explanation of symbols]

A, B ... observation points, A1, A2, A3, B1, B2, B3
... Auxiliary point 3 ... GPS receiving unit, 4 ... Data recording unit, 5 ... Recording control unit 6 ... Operation unit, 7 ... IC card (as recording means) 8 ... Data analysis device, 11 ... CPU, 12 ... ROM, 13 ... RAM 14 ... GPS signal receiving module, 17 ... Operation panel

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Massunori Tashiro 2-29-1, Higashiyamato-cho, Shimonoseki-shi, Yamaguchi Prefecture Inside the Shimonoseki Machinery and Maintenance Office, Fourth Port Construction Bureau, Ministry of Transport (72) Inventor Kenji Igan, Hyogo 9-52 Ashihara-cho, Nishinomiya City Furuno Electric Co., Ltd. (72) Inventor Tadao Hayashi 9-52 Ashihara-cho, Nishinomiya City, Hyogo Prefecture Furuno Electric Co., Ltd. (56) References JP-A-4-175606 (JP, A JP-A-8-145668 (JP, A) JP-A-8-166240 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01C 3/00-3/32 G01C 15 / 00-15/14 G01S 5/00-5/14 JICST file (JOIS)

Claims (2)

(57) [Claims] 1. A positioning method for measuring a distance or an azimuth from a first observation point to a second observation point, wherein a distance from the second observation point to the second observation point is calculated in the vicinity of the second observation point.
Auxiliary vector indicating the orientation to set a plurality of known auxiliary points, the respective provided a positioning receiver to a first observation point and the plurality of auxiliary points, by operating the plurality of positioning receivers in the same time zone An auxiliary baseline vector indicating a baseline vector between the first observation point and each of the auxiliary points using the data collected at the first observation point and the data collected at each of the auxiliary points. By adding the auxiliary vector to the auxiliary baseline vector, a plurality of temporary baseline vectors from the first observation point to the second observation point are obtained, and all of the plurality of temporary baseline vectors thus obtained are obtained.
Alternatively, a positioning method is characterized in that a base line vector from the first observation point to the second observation point is determined by averaging a part thereof . 2. In the vicinity of an observation point, a plurality of auxiliary points each having a known auxiliary vector indicating a distance and an azimuth to the observation point are set, and positioning is simultaneously performed at each of the auxiliary points by a positioning satellite. By adding the auxiliary vector, a plurality of candidates for the position of the observation point are determined, and
A positioning method, wherein the position of the observation point is determined by averaging all or part of the positions.