JP2008051681A - Positioning device, its control method, control program, and its recoding medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning device etc., capable of out putting the position with little positional error by two-dimensional measurement used in combination with the RTT in the asynchronous communication system. <P>SOLUTION: The positioning device 20 comprises: a presumed line calculation means for calculating the presumed line indicating the presumed position of the positioning device based on each pseudo distance of two SPS satellites and each orbital information of each SPS satellite; a presumed circle calculation means for calculating the presumed circle indicating the presumed position of the positioning device 20 based on the round travelling time of the communication signal between the communication base station 40 and the positioning device 20 and the position of the communication base station 40; a presumed Doppler displacement calculation means for calculating the presumed Doppler displacement based on the viewing line directional vector from the SPS satellite and the transmission frequency of satellite signal; a difference calculation means for calculating the difference between the presumed Doppler displacement and the measured Doppler displacement for each common point of the presumed line and the presumed circle; and an output position selection means for selecting the common point corresponding to the smaller difference as output position for the positioning device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a positioning device capable of performing two-dimensional positioning using an RTT in an asynchronous communication system, a control method thereof, a control program, and a recording medium thereof.

Conventionally, a positioning system that measures the current position of a GPS receiver using, for example, a GPS (Global Positioning System) that is a satellite navigation system has been put into practical use (for example, Patent Document 1).
The GPS receiver, for example, calculates GPS satellites that can be observed in the sky, and selects, for example, a set of four GPS satellites. The GPS receiver receives a signal from each GPS satellite (hereinafter referred to as a satellite signal) for each set of GPS satellites, and the time when the satellite signal is transmitted from each GPS satellite and the time when the GPS receiver arrives. The distance (hereinafter referred to as a pseudorange) between each GPS satellite and the GPS receiver is obtained by the difference between the two (hereinafter referred to as delay time). The GPS receiver calculates the positioning result of the current position of the GPS receiver using the position of each GPS satellite in the satellite orbit and the above-described pseudo distance. The GPS receiver calculates a positioning result for each GPS satellite set, selects a position considered to be close to the true position from a plurality of positioning results, and outputs the selected position. .
For the above positioning, it is necessary to receive satellite signals from at least three GPS satellites.
However, it is not always possible to receive satellite signals from three or more GPS satellites.
For this reason, a technique for positioning by using satellite signals from two GPS satellites and a carrier wave of a mobile phone has been proposed. For example, a signal carried on a carrier wave of a mobile phone calculates a communication time between a communication base station and a GPS receiver that also serves as a mobile phone (hereinafter referred to as RTT (Round Trip Time)). Using the position of the base station and the RTT, create an equation for the position of the GPS receiver (assuming two-dimensional positioning, the unknowns are latitude, longitude, and time), and two GPS satellites Together with two equations (three unknowns are latitude, longitude, and time) created using the satellite signal from the current position, the latitude and longitude of the current position are calculated.
JP 2000-131415 A (FIG. 1 etc.)

  However, in positioning using RTT together, the timing at which a signal carried on a carrier wave is transmitted from a communication base station needs to be synchronized with GPS time. For this reason, the communication base station needs to be a synchronous system such as gpsOne that is synchronized with the GPS time. The synchronization system has a problem that the cost required for the equipment for synchronization and the cost for adjustment of the equipment may become large.

  Accordingly, the present invention provides a positioning device that can perform two-dimensional positioning in combination with an RTT in an asynchronous communication system and output a position with little position error, a control method thereof, a control program, and a recording medium thereof. With the goal.

  According to the first aspect of the present invention, there is provided a positioning apparatus for performing two-dimensional positioning using a satellite signal from an SPS (Satellite Positioning System) satellite and a communication signal from a communication base station asynchronous with the SPS satellite. On the basis of satellite signal receiving means for receiving a satellite signal from the SPS satellite, each pseudo distance calculated by receiving the satellite signal from the two SPS satellites and orbit information of each SPS satellite, An estimated line calculating means for calculating an estimated line indicating an estimated position of the positioning device; a round trip time acquiring means for acquiring a round trip time for the communication signal to reciprocate between the communication base station and the positioning device; Based on time and the position of the communication base station, expected circle calculation means for calculating an expected circle indicating the expected position of the positioning device; a combination of the estimated line and the predicted circle Share point calculation means for calculating a number of share points, and expected Doppler shift calculation means for calculating an expected Doppler shift based on a line-of-sight direction vector from the SPS satellite to each of the share points and a transmission frequency of the satellite signal An actual Doppler shift that is an actual Doppler shift based on the actual reception frequency of the satellite signal and the transmission frequency, and an estimated Doppler shift for each shared point. A difference calculating means for calculating a difference between a shift and the measured Doppler shift, and an output position selecting means for selecting the shared point corresponding to the smaller difference as an output position for the positioning device to output, It is achieved by a positioning device characterized by having

According to the configuration of the first invention, the positioning device can calculate the estimated line. Since the positioning device performs two-dimensional positioning, there are three unknowns in positioning: latitude (x), longitude (y), and time (t). Here, an equation indicating the relationship between latitude (x) and longitude (y), that is, the estimated line can be obtained by appropriately selecting time t from the unknowns.
The positioning device can calculate the expected circle. For example, since the distance traveled by radio waves during one half of the round trip time can be calculated, a circle whose radius is the center of the position of the communication base station, that is, the expected circle is calculated. be able to.
The positioning device can calculate a common point between the estimated line and the predicted circle. Here, the number of shared points is not necessarily one.
The positioning device can calculate the expected Doppler shift for each of the shared points. The expected Doppler shift is different for each shared point.
Further, the positioning device can calculate the measured Doppler shift. The measured Doppler shift is an actual Doppler shift.
The positioning device can calculate the difference.
Then, the positioning device can select the shared point corresponding to the smaller difference as the output position. That the difference is small means that the accuracy of the expected Doppler shift is high. Since the predicted Doppler shift is calculated using a line-of-sight vector from the SPS satellite to each shared point, the closer the coordinate of the shared point is to the true position, the more accurate the predicted Doppler shift is. Get higher. For this reason, that the difference is small means that the shared point corresponding to the difference is close to the true position.
For this reason, the positioning device can output a highly accurate position by selecting the shared point corresponding to the smaller difference as the output position.
As a result, the positioning device can perform two-dimensional positioning in combination with RTT in an asynchronous communication system and output a position with little position error.

  According to a second invention, in the configuration of the first invention, the predicted Doppler shift calculating means calculates the predicted Doppler shift for each of the two SPS satellites. The shift calculating means is configured to calculate the measured Doppler shift for each of the two SPS satellites used by the predicted Doppler shift calculating means, and the difference calculating means is configured to calculate the expected Doppler shift. The difference is calculated for each of the two SPS satellites used by the means, and the output position selection means is such that the differences for the plurality of shared points for one of the SPS satellites are substantially equal. Is configured to select the output position based on the difference for the plurality of shared points for the other SPS satellite. It is positioning device, characterized in that.

Depending on the positional relationship between the plurality of shared points and the SPS satellites, the line-of-sight direction vectors for the shared points may exhibit substantially the same speed. In this case, the differences for the plurality of shared points are substantially equal.
In this regard, according to the configuration of the second aspect of the invention, even if the differences for the plurality of shared points for one of the SPS satellites are approximately equal, the plurality of shared points for the other SPS satellite. The output position can be selected based on the difference.

  According to a third aspect of the present invention, in any one of the first and second aspects of the present invention, the third aspect includes reference position calculation means for calculating a reference position based on the plurality of shared points, and the expected Doppler shift calculation. The means is configured to calculate the expected Doppler shift also for the reference position, the difference calculation means is configured to calculate the difference also for the reference position, and the output position selection means is If the difference for the shared point corresponding to the output position is less than or equal to the difference for the reference position, the output position is set as a final output position, and the output position selection means When the difference with respect to the corresponding shared point is larger than the difference with respect to the reference position, the reference position is set as a final output position. It is a positioning device.

When the accuracy of the positions of the plurality of shared points is low, the deviation from the true position becomes large. On the other hand, the reference position calculated based on a plurality of the shared points is deviated from the true position, but may be closer to the true position than the shared point with low accuracy.
In this regard, according to the configuration of the third invention, when the difference with respect to the shared point corresponding to the output position is larger than the difference with respect to the reference position, the reference position is set as a final output position. Therefore, a position closer to the true position can be output.

  A fourth invention is the positioning device according to the structure of the third invention, wherein the reference position is an average position of a plurality of the common points.

  According to a fifth aspect of the invention, in the configuration of the third aspect of the invention, the reference position is a center of gravity of a figure formed by the estimated line and the expected circle.

  According to a sixth aspect of the invention, in the configuration of the third aspect of the invention, the reference position is an intermediate point between the two common points in a circumferential portion of the expected circle defined by the two common points. It is a positioning device characterized by.

  According to a seventh invention, in the configurations of the first to sixth inventions, the output position selection means determines a position that is equidistant from the estimated line and the expected circle when the shared point does not exist. The positioning device is configured to calculate the output position.

If the estimated line and the expected circle do not intersect and do not touch, the shared point does not exist.
On the other hand, the positioning device should be located in the vicinity of the expected circle and the estimated line.
In this regard, according to the configuration of the seventh invention, the output position can be determined based on the estimated line and the predicted circle even when the shared point does not exist.

  According to an eighth invention, in any one of the first to sixth inventions, the output position selection means is a position on the expected circle when the common point does not exist, and The positioning device is configured to calculate a position closest to the estimated line as the output position.

  According to the ninth aspect of the present invention, there is provided a positioning apparatus for performing two-dimensional positioning using a satellite signal from an SPS satellite and a communication signal from a communication base station asynchronous with the SPS satellite. A satellite signal receiving step for receiving a satellite signal from the SPS satellite, and the positioning device based on the pseudoranges calculated by receiving the satellite signals from the two SPS satellites and the orbit information of the SPS satellites. An estimated line calculating step for calculating an estimated line indicating an estimated position of the device; and a round trip time acquiring step for acquiring a round trip time for the positioning device to reciprocate between the communication base station and the positioning device. The positioning device calculates an expected circle indicating an expected position of the positioning device based on the round trip time and the position of the communication base station; and the positioning device includes the estimated line. A shared point calculating step of calculating a plurality of shared points with the predicted circle, and the positioning device, based on a line-of-sight direction vector from the SPS satellite to each shared point and a transmission frequency of the satellite signal, An expected Doppler shift calculating step for calculating a shift, and the positioning device calculates an actual Doppler shift that is an actual Doppler shift based on the actual reception frequency and the transmission frequency of the satellite signal. Shift calculation step, the positioning device calculates a difference between the predicted Doppler shift and the measured Doppler shift for each shared point, and the positioning device corresponds to the smaller difference. And an output position selection step for selecting the shared point as an output position for the positioning device to output. It is achieved by the control method of the position device.

  According to the configuration of the ninth invention, similarly to the configuration of the first invention, two-dimensional positioning can be performed using RTT in an asynchronous communication system, and a position with little position error can be output.

  According to the tenth aspect of the present invention, there is provided a positioning device that performs two-dimensional positioning on a computer using a satellite signal from an SPS satellite and a communication signal from a communication base station asynchronous with the SPS satellite. A satellite signal receiving step for receiving satellite signals from the SPS satellites, and the positioning device based on the pseudoranges calculated by receiving the satellite signals from the two SPS satellites and the orbit information of the SPS satellites. An estimated line calculating step for calculating an estimated line indicating an estimated position of the positioning device; and a round trip time for the positioning device to acquire a round trip time for the communication signal to reciprocate between the communication base station and the positioning device. An obtaining step; an expected circle calculating step in which the positioning device calculates an expected circle indicating an expected position of the positioning device based on the round trip time and the position of the communication base station; and the positioning A common point calculating step for calculating a plurality of common points between the estimated line and the expected circle; and a positioning device, the line-of-sight vector from the SPS satellite to each of the common points, and the transmission frequency of the satellite signal. An expected Doppler shift calculating step for calculating an expected Doppler shift, and the positioning device is an actual measured Doppler shift that is an actual Doppler shift based on the actual reception frequency and the transmission frequency of the satellite signal. A measured Doppler shift calculating step for calculating a shift; and a positioning device for calculating a difference between the predicted Doppler shift and the measured Doppler shift for each shared point; and the positioning device, An output position selection step of selecting the shared point corresponding to the smaller difference as an output position for the positioning device to output. Is accomplished by the control program of the positioning device, characterized in that.

  According to the eleventh aspect of the present invention, there is provided a positioning device for performing two-dimensional positioning using a satellite signal from an SPS satellite and a communication signal from a communication base station asynchronous with the SPS satellite. A satellite signal receiving step for receiving satellite signals from the SPS satellites, and the positioning device based on the pseudoranges calculated by receiving the satellite signals from the two SPS satellites and the orbit information of the SPS satellites. An estimated line calculating step for calculating an estimated line indicating an estimated position of the positioning device; and a round trip time for the positioning device to acquire a round trip time for the communication signal to reciprocate between the communication base station and the positioning device. An obtaining step; an expected circle calculating step in which the positioning device calculates an expected circle indicating an expected position of the positioning device based on the round trip time and the position of the communication base station; and the positioning A common point calculating step for calculating a plurality of common points between the estimated line and the expected circle; and a positioning device, the line-of-sight vector from the SPS satellite to each of the common points, and the transmission frequency of the satellite signal. An expected Doppler shift calculating step for calculating an expected Doppler shift, and the positioning device is an actual measured Doppler shift that is an actual Doppler shift based on the actual reception frequency and the transmission frequency of the satellite signal. A measured Doppler shift calculating step for calculating a shift; and a positioning device for calculating a difference between the predicted Doppler shift and the measured Doppler shift for each shared point; and the positioning device, An output position selection step of selecting the shared point corresponding to the smaller difference as an output position for the positioning device to output. It is achieved by a computer readable recording medium recording a control program for the positioning apparatus, characterized in that to.

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
The embodiments described below are preferred specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these embodiments.

1 and 2 are schematic diagrams showing a terminal 20 and the like according to an embodiment of the present invention.
As shown in FIG. 1, the terminal 20 can receive signals S1 and S2 from GPS satellites 12a and 12b. The terminal 20 can perform two-dimensional positioning using a signal S1 from two GPS satellites 12a and the like and a communication signal CS of a base station 40 described later. The terminal 20 is an example of a positioning device. The GPS satellites 12a and the like are examples of SPS satellites. The signal S1 and the like are examples of satellite signals. Here, two-dimensional positioning means positioning for calculating latitude and longitude. The altitude is a known constant, for example, the altitude of the position of the base station 40.
The terminal 20 has a communication function, and can communicate with another terminal (not shown) via the base station 40 (see FIG. 2).

The signal S1 includes a C / A (Clear and Acquisition or Coarse and Access) code. The C / A code is one of pseudo-noise codes (hereinafter referred to as PN (Pseudo random noise code) codes). This C / A code is a signal having a bit rate of 1.023 Mbps and a bit length of 1,023 bits (= 1 msec). The C / A code is composed of 1,023 chips. The terminal 20 performs positioning of the current position using this C / A code.
The SPS satellite is not limited to a GPS satellite, and may be, for example, a satellite used in Galileo or a quasi-zenith satellite.

The terminal 20 is, for example, a mobile phone, a PHS (Personal Handy-phone System), a PDA (Personal Digital Assistance _), or the like, but is not limited thereto.

For example, the terminal 20 sets the speed of light to the time difference between the time when the C / A code is transmitted from each GPS satellite 12a and the time when the terminal 20 receives the C / A code (hereinafter referred to as “delay time”). The pseudo distance is calculated by multiplying.
If the terminal 20 can receive C / A codes from three or more GPS satellites 12a, etc., the terminal 20 can determine the current position using each pseudo-range and the position on the satellite orbit of each GPS satellite 12a. Can do.
Further, if the terminal 20 can receive the C / A code from the two GPS satellites 12a and the like, the terminal 20 can perform two-dimensional positioning using the position of the base station 40 and the communication radio wave CS.

When two-dimensional positioning is performed using signals S1 from two GPS satellites 12a etc., the positioning position is specified unless the terminal 20 is synchronized with the time (GPS time) calculated by the GPS satellite 12a etc. As described below, the positioning position is generally a set of estimated positions indicated by curves.
For example, the terminal 20 calculates a pseudo distance r1 for the GPS satellite 12a and a pseudo distance r2 for the GPS satellite 12b.
As shown in FIG. 1A, when the true distance between the terminal 20 and the GPS satellite 12a is equal to the true distance between the terminal 20 and the GPS satellite 12b, the estimated coordinates on the xy plane of the terminal 20 are , A straight line L1 expressed by the equation y = fg (x) is drawn. This is because since the terminal 20 is not synchronized with the GPS time, the position of the GPS satellite 12a or the like in the orbit and the delay time cannot be specified accurately. In actual calculation, assuming a plurality of times t, the positions of the GPS satellites 12a and 12b in the orbit, the pseudo distances r1 and r2, and the coordinates on a plurality of xy planes are calculated. Then, when the coordinates on a plurality of xy planes are connected, a straight line L1 is obtained. For example, pseudo distances r1 and r2 are calculated corresponding to time t1, and pseudo distances r1a and r2a are calculated corresponding to time t2. The calculation of the coordinates at each time is calculated by convergence calculation. Although illustration is omitted, the positions of the GPS satellites 12a and the like are also different at time t1 and time t2. It is assumed that the altitude H is known as the position of the base station 40.
On the other hand, as shown in FIG. 1B, when the true distance between the terminal 20 and the GPS satellite 12a is not equal to the true distance between the terminal 20 and the GPS satellite 12b, the xy of the terminal 20 The estimated coordinates on the plane draw a curve L2 expressed by the equation y = fg (x).
Thus, even if the signal S1 or the like is received from the two GPS satellites 12a or the like, the position of the terminal 20 cannot be specified in the xy coordinates unless the terminal 20 is synchronized with the GPS time.
Considering this from another point of view, a sphere centered on the pseudorange r1 centered on the position of the GPS satellite 12a on the satellite orbit, and a pseudorange r2 centered on the position of the GPS satellite 12b on the satellite orbit. If the intersection point with the sphere is a circle and the altitude H is known as the position of the base station 40, it is one of two points that are at the altitude H in the circle. Since one of these two points is clearly incorrect, the position of the terminal 20 should be able to be specified. However, since the time error of the terminal 20 cannot be calculated with only two GPS satellites 12a and the like, the position of the terminal 20 cannot be specified at one point, and is a straight line L1 or a curved line L2. The straight line L1 and the curve L2 are examples of estimated lines.
Since the curve L2 is more general than the straight line L1, the following description will be made assuming that y = fg (x) indicates the curve L2. Further, the curve L2 and the straight line L1 are collectively referred to as an estimation line.

As illustrated in FIG. 2, the terminal 20 can receive the communication signal CS from the base station 40. The base station 40 is an example of a communication base station. The base station 40 is not synchronized with the time (GPS time) of the GPS satellite 12a or the like. That is, the base station 40 is a communication base station in a time asynchronous communication system. The base station 40 is located at a fixed position, and the position is known.
The terminal 20 can calculate the distance d between the base station 40 and the terminal 20 based on the time that the communication signal CS travels between the base station 40 and the terminal 20. Then, the terminal 20 can calculate a circle L3 with the distance d as a radius around the position of the base station 40. This circle L3 is a function of x and y, and is represented by y = fr (x).
Although the curve L2 and the circle L3 may contact each other at the common point P0 as shown in FIG. 2A, generally, as shown in FIG. 2B, the curve L2 and the circle L3 have the common point P1 and the circle L3. It intersects at two points of P2 or does not have a common point.

In such a state, as described below, the terminal 20 can perform two-dimensional positioning in combination with RTT in an asynchronous communication system and output an appropriate position.

(Main hardware configuration of terminal 20)
FIG. 3 is a schematic diagram showing the main hardware configuration of the terminal 20.
As illustrated in FIG. 3, the terminal 20 includes a computer, and the computer includes a bus 22.
A CPU (Central Processing Unit) 24 and a storage device 26 are connected to the bus 22. The storage device 26 is, for example, a RAM (Random Access Memory) or a ROM (Read Only Memory).

In addition, the bus 22 receives signals from an input device 28 for receiving various information and commands, a power supply device 30, a communication device 32 for transmitting and receiving communication signals to and from the base station 40, a GPS satellite 12a, and the like. A GPS device 34 for receiving S1 and the like and a display device 36 for displaying various information are connected.
A clock 38 is connected to the bus 22.

(About main software configuration of terminal 20)
FIG. 4 is a schematic diagram showing a main software configuration of the terminal 20.
As shown in FIG. 4, the terminal 20 includes a control unit 100 that controls each unit, a communication unit 102 that corresponds to the communication device 32 in FIG. 3, a GPS unit 104 that corresponds to the GPS device 34, and a display unit that corresponds to the display device 36. 106, a time measuring unit 108 corresponding to the clock 38, and the like.
The terminal 20 also includes a first storage unit 110 that stores various programs and a second storage unit 150 that stores various information.

As illustrated in FIG. 4, the terminal 20 stores satellite orbit information 152 in the second storage unit 150. The satellite orbit information 152 includes an Almanac 152a indicating an approximate orbit of all GPS satellites 12a and the like, and an Ephemeris 152b indicating a precise orbit of each GPS satellite 12a and the like. The terminal 20 acquires the almanac 152a and the ephemeris 152b by receiving and decoding the signal S1 and the like from the GPS satellite 12a and the like.
The terminal 20 uses the satellite orbit information 152 for positioning based on the signal S1 and the like and the communication signal CS.

As illustrated in FIG. 4, the terminal 20 stores a satellite signal reception program 112 in the first storage unit 110. The satellite signal reception program 112 is a program for the control unit 100 to receive the signal S1 and the like from the GPS satellite 12a and the like. The satellite signal reception program 112 and the control unit 100 are examples of satellite signal reception means.
Specifically, the control unit 100 refers to the almanac 152a, determines the GPS satellites 12a and the like that can be observed at the current time, and receives the signal S1 and the like from the observable GPS satellites 12a and the like. At this time, for example, the previous positioning position is used as the reference self-position.

As illustrated in FIG. 4, the terminal 20 stores an estimated line calculation reception program 114 in the first storage unit 110.
The control unit 100 receives the signal S1 and the like based on the estimated line calculation reception program 114, performs correlation processing with the replica C / A code held by the terminal 20, and performs the code phase CPb1 for the GPS satellite 12a, and The code phase CPb2 for the GPS satellite 12b is calculated.
The control unit 100 stores code phase information 154 indicating the code phases CPb1 and CPb2 in the second storage unit 150.
Further, the control unit 100 calculates pseudo distances r1 and r2 (see FIGS. 1 and 2) based on the code phases CPb1 and CPb2. At this time, the pseudo distances r1 and r2 are calculated using the current time t calculated by the timer 108.
The control unit 100 stores pseudo distance information 156 indicating the pseudo distances r1 and r2 in the second storage unit 150.
Note that, unlike the present embodiment, the control unit 100 may calculate the pseudo distances r1 and r2 based on the delay time.

  Subsequently, the control unit 100 uses the ephemeris 152b to calculate the positions of the GPS satellites 12a and 12b on the orbit at the current time. At this time, the current time t calculated by the timer 108 is used as the current time.

Here, since the current time t is not synchronized with the GPS time, it is not always an accurate time. Therefore, the control unit 100 calculates the above-described pseudo distance and the positions of the GPS satellites 12a and 12b at each time even at times before and after the current time t.
And the control part 100 calculates the curve L2 (refer FIG.1 and FIG.2) which shows the estimated position of the terminal 20 based on the pseudorange r1 and r2 in several time, and the position of GPS satellite 12a and 12b. That is, the estimated line calculation reception program 114 and the control unit 100 are examples of estimated line calculation means.
The control unit 100 stores estimated line information 158 indicating the curve L2 in the second storage unit 150.

As illustrated in FIG. 4, the terminal 20 stores a base station information acquisition program 116 in the first storage unit 110. The base station information acquisition program 116 is a program for the control unit 100 to communicate with the base station 40 and acquire the base station position Q and RTT (Round Trip Time). RTT is the time required for the communication signal CS to reciprocate between the base station 40 and the terminal 20. RTT is an example of a round trip time. The base station information acquisition program 116 and the control unit 100 are an example of a round trip time acquisition unit.
The control unit 100 extracts information indicating the base station position Q included in the communication signal CS. Then, the control unit 100 stores the base station position information 160 indicating the base station position Q in the second storage unit 150.

A specific frame of the communication signal CS transmitted from the base station 40 is returned from the terminal 20 to the base station 40. The base station 40 calculates the RTT by measuring the time when the specific frame is transmitted and the time when the specific frame is received. Then, the base station 40 includes information indicating the RTT in the communication signal CS and transmits it to the terminal 20.
The terminal 20 extracts information indicating the RTT included in the communication signal CS. Then, the control unit 100 stores RTT information 162 indicating RTT in the second storage unit 150.
Note that, unlike the present embodiment, the terminal 20 may transmit a specific frame to the base station 40 and receive the specific frame from the base station 40. The time between the time when the terminal 20 transmits a specific frame and the time when the terminal 20 receives the frame may be RTT.

As illustrated in FIG. 4, the terminal 20 stores an expected circle radius calculation program 118 in the first storage unit 110. The expected circle radius calculation program 118 is a program for the control unit 100 to calculate the radius d of the expected circle L3 (see FIG. 2) based on the RTT. The control unit 100 calculates the distance traveled by the radio wave in a half time of the RTT, and calculates the radius d. Since radio waves propagate at the speed of light, the radius d can be calculated by multiplying the time of light by one-half of the RTT.
The control unit 100 stores radius information 164 indicating the radius d in the second storage unit 150.

As illustrated in FIG. 4, the terminal 20 stores an expected circle calculation program 120 in the first storage unit 110. The predicted circle calculation program 120 is a program for the control unit 100 to calculate the predicted circle L3 (see FIG. 2) based on the radius d and the base station position Q. The expected circle radius calculation program 118, the expected circle calculation program 120, and the control unit 100 described above are examples of expected circle calculation means.
The control unit 100 stores predicted circle information 166 indicating the calculated predicted circle L3 in the second storage unit 150.

As illustrated in FIG. 4, the terminal 20 stores a shared point calculation program 122 in the first storage unit 110. The shared point calculation program 122 is a program for the control unit 100 to calculate a shared point between the curve L2 and the expected circle L3. The share point calculation program 122 and the control unit 100 are examples of share point calculation means.
For example, the control unit 100 calculates the shared points P1 and P2 (see FIG. 2B). The control unit 100 stores the shared point information 168 indicating the shared points P1 and P2 in the second storage unit 150.

As illustrated in FIG. 4, the terminal 20 stores a current position determination program 124 in the first storage unit 110.
The current position determination program 124 includes an expected Doppler shift calculation program 124a, an actual measurement Doppler shift calculation program 124b, a difference calculation program 124c, and an output position selection program 124d.

FIG. 5 is an explanatory diagram of the expected Doppler shift calculation program 124a.
In the predicted Doppler shift calculation program 124a, the control unit 100 calculates the predicted Doppler shift DPest based on the line-of-sight direction vector from the GPS satellite 12a or the like to the common points P1 and P2 and the transmission frequency f0 such as the signal S1. It is a program for. The expected Doppler shift calculation program 124a and the control unit 100 are an example of an expected Doppler shift calculation unit.
The control unit 100 refers to the ephemeris 152b and calculates the GPS satellite coordinate Psa and the velocity vector Vga at the current time t. Then, the velocity vector Vga is decomposed in the direction (gaze direction) from the coordinate Psa toward the common point P1, and the velocity vector Vs1a in the gaze direction is obtained. The velocity vector Vs1a indicates the velocity V1a in the line-of-sight direction. Similarly, the control unit 100 calculates a velocity vector Vs2a for the shared point P2.
Subsequently, the control unit 100 calculates the Doppler shift DPest1 at the shared point P1 using Equation 1, and calculates the Doppler shift DPest2 at the shared point P2 using Equation 2. Expressions 1 and 2 are expressions for calculating a general Doppler shift.
The transmission frequency f0 is known and is about 1.5 gigahertz (GHz).
The control unit 100 stores the predicted Doppler shift information 170 indicating the calculated Doppler shift DPest1 and the calculated Doppler shift DPest2 in the second storage unit 150.

FIG. 6 is an explanatory diagram of the measured Doppler shift calculation program 124b.
The measured Doppler shift calculation program 124b is a program for the control unit 100 to calculate the measured Doppler shift DPr that is the actual Doppler shift based on the actual reception frequency such as the signal S1 and the transmission frequency f0. . The measured Doppler shift calculation program 124b and the control unit 100 are an example of the measured Doppler shift calculation means.
The control unit 100 calculates the measured Doppler shift DPr by Equation 3 that subtracts the known transmission frequency f0 from the actual reception frequency fr.
The control unit 100 stores measured Doppler shift information 172 indicating the calculated measured Doppler shift DPr in the second storage unit 150.

FIG. 7 is an explanatory diagram of the difference calculation program 124c. In the difference calculation program 124c, the control unit 100 calculates the difference DPdif between the predicted Doppler shift DPest and the measured Doppler shift DPr for each of the shared points P1 and P2. It is a program for. The difference DPdif is an example of a difference. The difference calculation program 124c and the control unit 100 are an example of a difference calculation unit.
The control unit 100 calculates a difference DPdif1 for the shared point P1 by Expression 4 that subtracts the measured Doppler shift DPr from the predicted Doppler shift DPest1 for the shared point P1. Similarly, the control unit 100 calculates the difference DPdif2 with respect to the shared point P2 by Expression 5.
The control unit 100 stores the difference information 174 indicating the calculated differences DPdif1 and DPdif2 in the second storage unit 150.

FIG. 8 is an explanatory diagram of the output position selection program 124d.
The output position selection program 124d is a program for the control unit 100 to select the shared point P1 or P2 corresponding to the smaller difference DPdif1 or DPdif2 as the output position Pfix for the terminal 20 to display on the display device 36. is there. The output position selection program 124d and the control unit 100 are an example of output position selection means.
As shown in FIG. 8, when DPdif1 is smaller than DPdif2, the control unit 100 selects the shared point P1 and sets it as the output position Pfix. On the other hand, when DPdif2 is smaller than DPdif1, the control unit 100 selects the common point P2 as the output position Pfix.
The control unit 100 stores output position information 176 indicating the output position Pfix in the second storage unit 150.

As illustrated in FIG. 4, the terminal 20 stores a position output program 126 in the first storage unit 110. The position output program 126 is a program for the control unit 100 to display the output position Pfix on the display device 36.

When there is no common point between the estimated line L2 and the expected circle L3, the control unit 100 determines the output position Pfix as follows.

FIG. 9 is a diagram illustrating an example of a method for determining the output position Pfix when there is no shared point.
When there is no common point between the curve L2 and the predicted circle L3, the control unit 100 calculates a point equidistant from the curve L2 and the predicted circle L3 as shown in FIG. Let Pfix.
If the curve L2 and the expected circle L3 do not intersect and do not touch, there is no shared point. On the other hand, the terminal 20 should be located in the vicinity of the expected circle L3 and the curve L2.
In this regard, the control unit 100 can calculate the current position Pfix based on the curve L2 and the expected circle L3 even when there is no shared point.

Unlike the present embodiment, when there is no common point between the curve L2 and the predicted circle L3, the control unit 100 does not change the position on the predicted circle L3 as shown in FIG. 9B. Thus, the position closest to the curve L2 may be calculated as the current position Pfix.

The terminal 20 is configured as described above.
As described above, the terminal 20 can calculate the curve L2.
Further, the terminal 20 can calculate the expected circle L3.
Then, the terminal 20 can calculate a common point between the curve L2 and the expected circle L3. Here, the number of shared points is not necessarily one.
In this regard, the terminal 20 can select an output position Pfix for output to the display device 36 from a plurality of shared points.
Specifically, the terminal 20 can calculate the expected Doppler shift DPest for each of the shared points P1 and P2.
The expected Doppler shift DPest is different for each sharing point P1 and P2.
Further, the terminal 20 can calculate the measured Doppler shift DPr. The measured Doppler shift DPr is an actual Doppler shift.
Then, the terminal 20 can calculate the difference DPdif.
Then, the terminal 20 can select the shared point P1 or P2 corresponding to the smaller difference DPdif as the output position Pfix. The small difference DPdif means that the accuracy of the expected Doppler shift DPest is high. Since the predicted Doppler shift DPest is calculated using the line-of-sight vector from the GPS satellite 12a to each shared point P1 or P2, the closer the coordinate of the shared point P1 or P2 is to the true position, the more the expected Doppler shift DPest is. The accuracy of. Therefore, a small difference DPdif means that the shared point P1 or P2 corresponding to the difference DPdif is close to the true position.
For this reason, the terminal 20 can output a highly accurate position by selecting the shared point P1 or P2 corresponding to the smaller difference DPdif as the output position Pfix.
As a result, the terminal 20 can perform two-dimensional positioning in combination with RTT in an asynchronous communication system and output a position with little position error.

The above is the configuration of the terminal 20 of the present embodiment. Hereinafter, an example of the operation will be mainly described with reference to FIG.
FIG. 10 is a schematic flowchart showing an operation example of the terminal 20 of the present embodiment.

First, the terminal 20 receives a signal S1 and the like from the GPS satellite 12a and the like (step ST1 in FIG. 10). This step ST1 is an example of a satellite signal receiving step.
Subsequently, the terminal 20 calculates an estimated line L2 (see FIGS. 1 and 2) (step ST2). This step ST2 is an example of an estimated line calculation step.

Subsequently, the terminal 20 acquires the RTT (step ST3). This step ST3 is an example of a round trip time acquisition step.
Subsequently, the terminal 20 calculates an expected circle L3 (step ST4). This step ST4 is an example of an expected circle calculation step. In step ST4, the radius d of the expected circle L3 is calculated based on the RTT, and the predicted circle L3 is calculated based on the radius d3 and the base station position Q.

Subsequently, the terminal 20 calculates a common point between the curve L2 and the expected circle L3 (step ST5). This step ST5 is an example of a shared point calculation step. Here, the following explanation will be made assuming that there are two common points.
Subsequently, the terminal 20 calculates an expected Doppler shift DPest for each of the shared points P1 and P2 (step ST6). This step ST6 is an example of an expected Doppler shift calculation step.

Subsequently, the terminal 20 calculates the measured Doppler shift DPr (step ST7). This step ST7 is an example of a measured Doppler shift calculation step.
Subsequently, the terminal 20 calculates a difference DPdif between the predicted Doppler shift DPest and the measured Doppler shift DPr for each of the shared points P1 and P2 (Step ST8). This step ST8 is an example of a difference calculating step.

Subsequently, the terminal 20 selects the shared point P1 or P2 corresponding to the smaller difference DPdif as the output position Pfix (step ST9). This step ST9 is an example of an output position selection step.
Subsequently, the terminal 20 outputs the output position Pfix (step ST10).

  Through the above-described steps, the terminal 20 can perform two-dimensional positioning using RTT in an asynchronous communication system and output a position with little position error.

(Second Embodiment)
Next, the terminal 20A of the second embodiment will be described. Since the configuration of the terminal 20A of the second embodiment is similar to that of the terminal 20 of the first embodiment, common parts are the same as those in the first embodiment, and the description thereof will be omitted. The explanation will be focused on.

For example, depending on the relative positions of the GPS satellite 12a and the shared points P1 and P2, the differences DPdif1 and DPdif2 may be substantially equal. In this case, it cannot be determined which of the shared points P1 and P2 is closer to the true position.
In this regard, the terminal 20A can determine the output position Pfix even in such a case as described below.

FIG. 11 is a schematic diagram illustrating a main software configuration of the terminal 20A.
As illustrated in FIG. 11, the terminal 20A stores a current position determination program 124A in the first storage unit 110. The current position determination program 124A includes an expected Doppler shift calculation program 124aA, an actual measurement Doppler shift calculation program 124bA, a difference calculation program 124cA, and an output position selection program 124dA.

FIG. 12 is an explanatory diagram of the expected Doppler shift calculation program 124aA.
As illustrated in FIG. 12, the control unit 100 calculates DPest1 and DPest2 for the two GPS satellites 12a and 12b used to generate the curve L2, based on the expected Doppler shift calculation program 124aA.
That is, the control unit 100 calculates DPest1 and DPest2 for the GPS satellite 12a and further calculates DPest1 and DPest2 for the GPS satellite 12b.

FIG. 13 is an explanatory diagram of the measured Doppler shift calculation program 124bA.
As shown in FIG. 13, the control unit 100 calculates the measured Doppler shift DPr for each of the two GPS satellites 12a and 12b.
That is, the control unit 100 calculates the measured Doppler shift DPr for the GPS satellite 12a, and further calculates the measured Doppler shift DPr for the GPS satellite 12b.

FIG. 14 is an explanatory diagram of the difference calculation program 124cA.
As shown in FIG. 14, the control unit 100 calculates the differences DPdif1 and DPdif2 for the two GPS satellites 12a and 12b, respectively.
That is, the control unit 100 calculates the differences DPdif1a and DPdif2a for the GPS satellite 12a, and further calculates the differences DPdif1b and DPdif2b for the GPS satellite 12b.

FIG. 15 is an explanatory diagram of the output position selection program 124dA.
As shown in FIG. 15, when the differences DPdif1a and DPdif2a are substantially equal, the control unit 100 compares the differences DPdif1b and DPdif2b to determine which of the sharing points P1 or P2 corresponding to the smaller difference DPdif1b or DPdif2b. Is supposed to be selected.

  As described above, the terminal 20A has a plurality of common points P1 and P2 for the other GPS satellite 12b even if the differences DPdif for the common points P1 and P2 for the one GPS satellite 12a are substantially equal. The output position Pfix can be selected based on the difference DPdif.

(Third embodiment)
Next, the terminal 20B according to the third embodiment will be described. Since the configuration of the terminal 20B of the third embodiment is similar to that of the terminal 20 of the first embodiment, common portions are denoted by the same reference numerals, and the description thereof is omitted. The explanation will be focused on.

  When the accuracy of the positions of the shared points P1 and P2 is low, the deviation from the true position becomes large. Rather, the true position may be close to the position obtained by statistically processing the shared points P1 and P2. Therefore, as described below, the terminal 20B calculates the reference position Pref based on the average position of the shared points P1 and P2, and when the reference position Pref is closer to the true position than the shared points P1 and P2. The reference position Pref is selected as the final output position Pfix.

FIG. 16 is a schematic diagram illustrating a main software configuration of the terminal 20B.
As illustrated in FIG. 11, the terminal 20B stores a reference position calculation program 128 in the first storage unit 110. The reference position calculation program 128 is a program for the control unit 100 to calculate the reference position Pref based on the shared points P1 and P2. The reference position Pref is an example of a reference position. The reference position calculation program 128 and the control unit 100 are an example of a reference position calculation unit.

FIG. 17 is an explanatory diagram of the reference position calculation program 128.
As illustrated in FIG. 17, the control unit 100 calculates an average position of the shared points P1 and P2, and sets the average position as the reference position Pref.
The control unit 100 stores reference position information 178 indicating the calculated reference position Pref in the second storage unit 150.

As illustrated in FIG. 16, the terminal 20B stores a current position determination program 124B in the second storage unit 150. The current position determination program 124B includes an expected Doppler shift calculation program 124aB, an actual measurement Doppler shift calculation program 124bB, a difference calculation program 124cB, and an output position selection program 124dB.

FIG. 18 is an explanatory diagram of the expected Doppler shift calculation program 124aB.
As illustrated in FIG. 18, the control unit 100 calculates the predicted Doppler shift DPest for the common points P1 and P2 and the reference position Pref based on the predicted Doppler shift calculation program 124aB.
That is, the control unit 100 calculates DPest1 for the common point P1, calculates DPest2 for the common point P2, and further calculates DPest3 according to Expression 10 for the reference position Pref.

FIG. 19 is an explanatory diagram of the difference calculation program 124cB.
As illustrated in FIG. 14, the control unit 100 calculates a difference DPdif for each of the shared points P1 and P2 and the reference position Pref.
That is, the control unit 100 calculates the difference DPdif1 for the shared point P1, calculates the difference DPdif2 for the shared point P2, and further calculates the difference DPdif3 for the reference position Pref using Equation 11.

FIG. 20 is an explanatory diagram of the output position selection program 124 dB.
As illustrated in FIG. 20, the control unit 100 selects a position corresponding to the smallest difference among the differences DPdif1, DPdif2, and DPdif3 as the output position Pfix.

  As described above, the terminal 20B is configured to use the reference position Pdif as the final output position when the difference Pdif for the shared points P1 and P2 is larger than the difference Pdif for the reference position Pref. A position closer to the true position can be output.

(First modification)
FIG. 21 is an explanatory diagram of a first modification of the third embodiment.
As shown in FIG. 21, the control unit 100 is configured to calculate the center of gravity of the figure formed by the curve L2 and the expected circle L3 as the reference position Pref.

(Second modification)
FIG. 22 is an explanatory diagram of a second modification of the third embodiment.
As shown in FIG. 22, the control unit 100 sets an intermediate point between the two shared points P1 and P2 on the shorter arc of the circumference of the expected circle L3 defined by the two shared points P1 and P2. The reference position Pref is used.

Since the radius d of the predicted circle L3 is much shorter than the pseudo distances r1 and r2, even if there is an error in the RTT, the influence of the error of the RTT on the absolute value of the radius d of the predicted circle L3 is limited. For this reason, it may be considered that the terminal 20 is located on the expected circle L3.
The terminal 20 should be located near the curve 2.
Based on the current position determination program 124B, the control unit 100 determines the middle of the two shared points P1 and P2 on the shorter arc of the circumference of the expected circle L3 defined by the two shared points P1 and P2. Since the point is the current position Pfix, the position error can be reduced as compared to the case where the intermediate point between the two shared points is the current position Pfix.

(About programs and computer-readable recording media)
The computer receives the satellite signal reception step, the estimated line calculation step, the round trip time acquisition step, the predicted circle calculation step, the shared point calculation step, the predicted Doppler shift calculation step, and the measured Doppler shift calculation in the above-described operation example. It can be set as the control program of the positioning apparatus for performing a step, a difference calculation step, an output position selection step, etc.
Moreover, it can also be set as the computer-readable recording medium etc. which recorded the control program etc. of such a positioning apparatus.

  A program storage medium used to install the control program of the positioning device in the computer and make it executable by the computer is, for example, a flexible disk such as a floppy (registered trademark), a CD-ROM (Compact Disc Read Only). Semiconductor memory in which programs are temporarily or permanently stored as well as package media such as Memory, CD-R (Compact Disc-Recordable), CD-RW (Compact Disc-Rewriteable), DVD (Digital Versatile Disc), etc. It can be realized with a magnetic disk or a magneto-optical disk.

  The present invention is not limited to the embodiments described above. Furthermore, the above-described embodiments may be combined with each other.

It is the schematic which shows the terminal etc. of embodiment of this invention. It is the schematic which shows the terminal etc. of embodiment of this invention. It is the schematic which shows the main hardware constitutions of a terminal. It is the schematic which shows the main software structures of a terminal. It is explanatory drawing of an anticipated Doppler shift calculation program. It is explanatory drawing of the measurement Doppler shift calculation program. It is explanatory drawing of a difference calculation program. It is explanatory drawing of an output position selection program. It is a figure which shows an example of the determination method of an output position. It is a schematic flowchart which shows the operation example of a terminal. It is the schematic which shows the main software structures of a terminal. It is explanatory drawing of an anticipated Doppler shift calculation program. It is explanatory drawing of the measurement Doppler shift calculation program. It is explanatory drawing of a difference calculation program. It is explanatory drawing of an output position selection program. It is the schematic which shows the main software structures of a terminal. It is explanatory drawing of a reference position calculation program. It is explanatory drawing of an anticipated Doppler shift calculation program. It is explanatory drawing of a difference calculation program. It is explanatory drawing of an output position selection program. It is explanatory drawing of a modification. It is explanatory drawing of a modification.

Explanation of symbols

  12a, 12b ... GPS satellite, 20 ... terminal, 40 ... base station, 112 ... satellite signal reception program, 114 ... estimated line calculation program, 116 ... base station information acquisition program, 118 ... Expected circle radius calculation program, 120 ... Expected circle calculation program, 122 ... Shared point calculation program, 124 ... Current position determination program, 124a ... Expected Doppler shift calculation program, 124b ..Measured Doppler shift calculation program, 124c ... difference calculation program, 124d ... output position selection program

Claims (11)

A positioning device that performs two-dimensional positioning using a satellite signal from an SPS (Satellite Positioning System) satellite and a communication signal from a communication base station asynchronous with the SPS satellite,
Satellite signal receiving means for receiving satellite signals from the SPS satellite;
Estimated line calculating means for calculating an estimated line indicating an estimated position of the positioning device based on each pseudo distance calculated by receiving the satellite signals from the two SPS satellites and orbit information of each of the SPS satellites;
Round-trip time acquisition means for acquiring a round-trip time in which the communication signal reciprocates between the communication base station and the positioning device;
Based on the round trip time and the position of the communication base station, an expected circle calculation means for calculating an expected circle indicating an expected position of the positioning device;
A shared point calculating means for calculating a plurality of shared points between the estimated line and the predicted circle;
An expected Doppler shift calculating means for calculating an expected Doppler shift based on a line-of-sight direction vector from the SPS satellite to each of the shared points and a transmission frequency of the satellite signal;
An actual Doppler shift calculating means for calculating an actual Doppler shift that is an actual Doppler shift, based on the actual reception frequency of the satellite signal and the transmission frequency;
For each shared point, a difference calculating means for calculating a difference between the expected Doppler shift and the measured Doppler shift;
Output position selection means for selecting the shared point corresponding to the smaller difference as an output position for the positioning device to output;
A positioning device comprising: The expected Doppler shift calculating means is configured to calculate the predicted Doppler shift for each of the two SPS satellites,
The measured Doppler shift calculating means is configured to calculate the measured Doppler shift for each of the two SPS satellites used by the predicted Doppler shift calculating means,
The difference calculating means is configured to calculate the difference for each of the two SPS satellites used by the expected Doppler shift calculating means,
The output position selection means, when the difference for the plurality of shared points for one of the SPS satellites is substantially equal, based on the difference for the plurality of shared points for the other SPS satellite, The positioning device according to claim 1, wherein the positioning device is configured to select a position. Reference position calculation means for calculating a reference position based on a plurality of the shared points,
The expected Doppler shift calculating means is configured to calculate the expected Doppler shift for the reference position,
The difference calculation means is configured to calculate the difference for the reference position,
The output position selection means includes
If the difference for the shared point corresponding to the output position is less than or equal to the difference for the reference position, the output position is the final output position,
The output position calculation means is configured to use the reference position as a final output position when the difference with respect to the shared point corresponding to the output position is larger than the difference with respect to the reference position. The positioning device according to claim 1, wherein the positioning device is characterized in that   The positioning device according to claim 3, wherein the reference position is an average position of the plurality of shared points.   The positioning device according to claim 3, wherein the reference position is a center of gravity of a figure formed by the estimated line and the expected circle.   The positioning apparatus according to claim 3, wherein the reference position is an intermediate point between the two shared points in a circumferential portion of the expected circle defined by the two shared points.   2. The output position selection unit is configured to calculate, as the output position, a position that is equidistant from the estimated line and the predicted circle when the shared point does not exist. The positioning device according to claim 6.   The output position selection means is configured to calculate a position on the expected circle that is closest to the estimated line as the output position when the shared point does not exist. The positioning device according to any one of claims 1 to 6. A satellite signal receiving step in which a positioning device that performs two-dimensional positioning using a satellite signal from an SPS satellite and a communication signal from a communication base station asynchronous with the SPS satellite receives satellite signals from the SPS satellite;
Estimation that the positioning device calculates an estimation line indicating the estimated position of the positioning device based on each pseudorange calculated by receiving the satellite signals from two SPS satellites and orbit information of each SPS satellite A line calculation step;
A round trip time acquisition step in which the positioning device acquires a round trip time in which the communication signal reciprocates between the communication base station and the positioning device;
An expected circle calculating step in which the positioning device calculates an expected circle indicating an expected position of the positioning device based on the round trip time and the position of the communication base station;
The positioning device calculates a shared point for calculating a plurality of shared points between the estimated line and the expected circle; and
An expected Doppler shift calculating step in which the positioning device calculates an expected Doppler shift based on a line-of-sight direction vector from the SPS satellite to each shared point and a transmission frequency of the satellite signal;
The positioning device calculates an actual Doppler shift that is an actual Doppler shift based on the actual reception frequency of the satellite signal and the transmission frequency; and
The positioning device calculates a difference between the expected Doppler shift and the measured Doppler shift for each of the shared points; and
An output position selecting step in which the positioning device selects the shared point corresponding to the smaller difference as an output position for the positioning device to output;
A method for controlling a positioning device, comprising: On the computer,
A satellite signal receiving step in which a positioning device that performs two-dimensional positioning using a satellite signal from an SPS satellite and a communication signal from a communication base station asynchronous with the SPS satellite receives satellite signals from the SPS satellite;
Estimation that the positioning device calculates an estimation line indicating the estimated position of the positioning device based on each pseudorange calculated by receiving the satellite signals from two SPS satellites and orbit information of each SPS satellite A line calculation step;
A round trip time acquisition step in which the positioning device acquires a round trip time in which the communication signal reciprocates between the communication base station and the positioning device;
An expected circle calculating step in which the positioning device calculates an expected circle indicating an expected position of the positioning device based on the round trip time and the position of the communication base station;
The positioning device calculates a shared point for calculating a plurality of shared points between the estimated line and the expected circle; and
An expected Doppler shift calculating step in which the positioning device calculates an expected Doppler shift based on a line-of-sight direction vector from the SPS satellite to each shared point and a transmission frequency of the satellite signal;
The positioning device calculates an actual Doppler shift that is an actual Doppler shift based on the actual reception frequency of the satellite signal and the transmission frequency; and
The positioning device calculates a difference between the expected Doppler shift and the measured Doppler shift for each of the shared points; and
An output position selecting step in which the positioning device selects the shared point corresponding to the smaller difference as an output position for the positioning device to output;
A positioning apparatus control program characterized by comprising: On the computer,
A satellite signal receiving step in which a positioning device that performs two-dimensional positioning using a satellite signal from an SPS satellite and a communication signal from a communication base station asynchronous with the SPS satellite receives satellite signals from the SPS satellite;
Estimation that the positioning device calculates an estimation line indicating the estimated position of the positioning device based on each pseudorange calculated by receiving the satellite signals from two SPS satellites and orbit information of each SPS satellite A line calculation step;
A round trip time acquisition step in which the positioning device acquires a round trip time in which the communication signal reciprocates between the communication base station and the positioning device;
An expected circle calculating step in which the positioning device calculates an expected circle indicating an expected position of the positioning device based on the round trip time and the position of the communication base station;
The positioning device calculates a shared point for calculating a plurality of shared points between the estimated line and the expected circle; and
An expected Doppler shift calculating step in which the positioning device calculates an expected Doppler shift based on a line-of-sight direction vector from the SPS satellite to each shared point and a transmission frequency of the satellite signal;
The positioning device calculates an actual Doppler shift that is an actual Doppler shift based on the actual reception frequency of the satellite signal and the transmission frequency; and
The positioning device calculates a difference between the expected Doppler shift and the measured Doppler shift for each of the shared points; and
An output position selecting step in which the positioning device selects the shared point corresponding to the smaller difference as an output position for the positioning device to output;
The computer-readable recording medium which recorded the control program of the positioning apparatus characterized by performing these.

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