Positioning device and positioning method

Abstract

Provided is a positioning device comprising: a plurality of signal reception units (301) that are provided to a respective plurality of satellites (1) and that acquire complex signal vectors of signals received by said satellites (1); a correlation processing unit (302) that calculates information pertaining to TDOA and FDOA by correlation processing between said complex signal vectors; a ground control point calculation unit (303) that calculates ground control points corresponding to said TDOA and FDOA; a coordinate transformation unit (306) that transforms said ground control points into information pertaining to latitude and longitude; a frequency distribution calculation unit (307) that calculates a frequency distribution of ground control points; a ground control point extraction unit (308) that extracts, from said frequency distribution, a ground control point included in a region having the greatest frequency; and a position estimation unit that estimates the position of a target radio source (10). Also provided is a positioning method.

Description

Positioning device and positioning method

[0001] The present disclosure relates to a positioning device and a positioning method for locating an unknown target radio wave source.

[0002] Positioning of an unknown target radio wave source using a satellite has traditionally been performed by performing correlation processing between signals received by the satellite, followed by positioning using information on the time difference of arrival (TDOA) and frequency difference (FDOA) of the signals (see, for example, Non-Patent Document 1).

[0003] On the other hand, if an unknown target radio wave source emits radar waves, such as pulse waves, multiple candidate TDOA and FDOA information will be generated. Therefore, in this case, ambiguity will occur in the positioning results, making it difficult to estimate the true position of the target radio wave source. As a countermeasure, a method has been proposed in which a satellite is equipped with an array antenna for azimuth estimation, and the azimuth information is used to remove ambiguity and estimate the position of the target radio wave source (see, for example, Non-Patent Document 2).

[0004] D. P. Haworth, "Interference localization for EUTELSAT satellites - the first European transmitter location system," International Journal of Satellite Communications, vol. 15, 155-183 (1997). Ashima, T. Fukushima, and T. Takahashi, "Radar pulse ambiguity elimination using DOA in TDOA / FDOA positioning using two satellites," IEICE Technical Report SANE2022

[0005] In this way, the method using azimuth information can extract a control point originating from a target radio wave source from among multiple ambiguities. However, this method requires azimuth information of the target radio wave source. Therefore, the installation of an array antenna to acquire azimuth information increases the hardware scale and cost, which is an issue.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a positioning device that can locate an unknown target radio wave source without using directional information, regardless of the type of the target radio wave source.

[0007] a correlation processing unit that calculates information on TDOA and FDOA by correlation processing between the complex signal vectors based on the complex signal vectors acquired by the signal receiving units; a control point calculation unit that calculates control points corresponding to the TDOA and FDOA based on the TDOA and FDOA information calculated by the correlation processing unit; a coordinate conversion unit that converts the control points into latitude and longitude information based on the control points for a plurality of times calculated by the control point calculation unit; a frequency distribution calculation unit that calculates a frequency distribution of the control points based on the latitude and longitude information obtained by the coordinate conversion unit; a control point extraction unit that extracts control points included in an area with the maximum frequency from the frequency distribution based on the frequency distribution calculated by the frequency distribution calculation unit; and a position estimation unit that estimates the position of a target radio wave source based on the control points extracted by the control point extraction unit.

[0008] According to the present disclosure, with the above-described configuration, it is possible to locate the position of an unknown target radio wave source without using azimuth information, regardless of the type of the target radio wave source.

[0009] FIG. 1 is a block diagram showing a schematic configuration example of a positioning system including a positioning device according to embodiment 1. FIG. 2 is a block diagram showing a schematic configuration example of a positioning device according to embodiment 1. FIG. 3 is a flowchart showing an example of an operation procedure of the positioning device according to embodiment 1. FIG. 4 is a diagram showing an example of a frequency distribution created by a frequency distribution calculation unit in embodiment 1. FIG. 5 is a diagram for explaining an example of an outline of the operation of a control point extraction unit in embodiment 1. FIG. 6 is a diagram for explaining the reason why a control point included in an area with the maximum frequency is extracted in the control point extraction unit in embodiment 1. ２and an example of the probability that a control point corresponding to each value exists within the error ellipse. FIG. 1 is a diagram showing an example of the operation of the error ellipse calculation unit in the first embodiment. FIG. 2 is a diagram showing an example of the operation of the common part calculation unit in the first embodiment. FIG. 3 is a block diagram showing an example of the schematic configuration of a positioning system including a positioning device according to a second embodiment. FIG. 4 is a block diagram showing an example of the schematic configuration of a positioning device according to the second embodiment. FIG. 5 is a flowchart showing an example of the operating procedure of the positioning device according to the second embodiment. FIG. 6 is a block diagram showing an example of the schematic configuration of a positioning system including a positioning device according to a third embodiment. FIG. 7 is a block diagram showing an example of the schematic configuration of a positioning device according to the third embodiment. FIG. 8 is a flowchart showing an example of the operating procedure of the positioning device according to the third embodiment. FIG. 9 is a block diagram showing an example of the schematic configuration of a positioning device according to the third embodiment.

[0010] Hereinafter, embodiments will be described in detail with reference to the drawings. Note that components assigned the same reference numerals throughout the drawings have the same configuration and the same function. Embodiment 1. FIG. 1 is a block diagram showing an example of the schematic configuration of a positioning system including a positioning device 3 according to embodiment 1. As shown in FIG. 1, the positioning system includes a plurality of satellites 1, a plurality of ground station antennas 2, and the positioning device 3. In addition to the positioning system, FIG. 1 also shows a target radio wave source 10, which is the object of positioning. This target radio wave source 10 is a radio wave source whose position is unknown.

[0011] The number of ground station antennas 2 provided corresponds to the number of satellites 1. Figure 2 shows a case where three satellites 1-#1 to 1-#3 are provided as the satellites 1, and three ground station antennas 2-#1 to 2-#3 are provided as the ground station antennas 2.

[0012] A satellite 1 receives a signal from a target radio source 10. The signal received by the satellite 1 is transmitted to an antenna 2 at a ground station.

[0013] In FIG. 1, satellite 1-#1 receives a signal from target radio wave source 10. The signal received by satellite 1-#1 is transmitted to ground station antenna 2-#1. Satellite 1-#2 also receives a signal from target radio wave source 10. The signal received by satellite 1-#2 is transmitted to ground station antenna 2-#2. Satellite 1-#3 also receives a signal from target radio wave source 10. The signal received by satellite 1-#3 is transmitted to ground station antenna 2-#3.

[0014] The ground station antenna 2 receives the signal received by the satellite 1. The signal received by the ground station antenna 2 is transmitted to the positioning device 3.

[0015] In FIG. 1 , ground station antenna 2-#1 receives signals received by satellite 1-#1. The signals received by this ground station antenna 2-#1 are transmitted to positioning device 3. Ground station antenna 2-#2 receives signals received by satellite 1-#2. The signals received by ground station antenna 2-#2 are transmitted to positioning device 3. Ground station antenna 2-#3 receives signals received by satellite 1-#3. The signals received by ground station antenna 2-#3 are transmitted to positioning device 3.

[0016] The positioning device 3 locates the position of the target radio wave source 10 using information on TDOA and FDOA calculated by correlation processing of signals received by each satellite 1. This positioning device 3 is applicable to various fields such as radar systems and satellite communication systems. As shown in Fig. 2, this positioning device 3 includes a plurality of signal receiving units 301, a correlation processing unit 302, a control point calculation unit 303, a control point accumulation unit 304, an accumulation time determination unit 305, a coordinate conversion unit 306, a frequency distribution calculation unit 307, a control point extraction unit 308, an error ellipse calculation unit 309, a common part calculation unit 310, and a centroid calculation unit 311.

[0017] The number of signal receiving units 301 provided corresponds to the number of satellites 1. Fig. 2 shows a case where three signal receiving units 301-#1 to 301-#3 are provided as the signal receiving unit 301. Also in Fig. 2, the correlation processing unit 302 has correlation processing units 302-#1 to 302-#3 corresponding to the sets of satellites 1. Also in Fig. 2, the orientation point calculation unit 303 has orientation point calculation units 303-#1 to 303-#3 corresponding to the sets of satellites 1.

[0018] The signal receiving unit 301 acquires a complex signal vector of a signal received by a corresponding satellite 1 based on a signal received by a corresponding ground station antenna 2. Specifically, the signal receiving unit 301 first performs various signal processing, such as amplification, band-pass filtering, and frequency conversion, on the RF (radio frequency) output of the ground station antenna 2 to generate an analog signal. This analog signal is a complex signal having an in-phase component and a quadrature component. The signal receiving unit 301 then acquires a complex signal vector by converting this analog signal into a received signal, which is a digital complex signal. The signal indicating the complex signal vector acquired by the signal receiving unit 301 is output to the correlation processing unit 302.

[0019] In FIG. 2, the signal receiving unit 301-#1 receives the complex signal vector x of the signal received by the satellite 1-#1 based on the signal received by the ground station antenna 2-#1. １ (t) is acquired by the signal receiving unit 301-#1. １ The signal indicating (t) is output to correlation processors 302-#1 and 302-#3. Furthermore, signal receiver 301-#2 calculates the complex signal vector x of the signal received by satellite 1-#2 based on the signal received by ground station antenna 2-#2. ２ (t) is acquired by the signal receiving unit 301-#2. ２ The signal indicating (t) is output to correlation processors 302-#1 and 302-#2. Furthermore, signal receiver 301-#3 calculates the complex signal vector x of the signal received by satellite 1-#3 based on the signal received by ground station antenna 2-#3.３ (t) is acquired by the signal receiving unit 301-#3. ３ A signal indicating (t) is output to correlation processing section 302-#2 and correlation processing section 302-#3.

[0020] The correlation processor 302 calculates TDOA and FDOA information by correlation processing between the complex signal vectors acquired by each signal receiver 301. Specifically, the correlation processor 302 calculates TDOA and FDOA information by extracting peak values ​​of a CAF (Cross Ambiguity Function) according to the method described in Non-Patent Document 1 as the correlation processing between the complex signal vectors. Note that if the target radio wave source 10 is a radar wave source, there will be multiple CAF peak values, and as a result, multiple pieces of TDOA and FDOA information will be calculated. Signals indicating the TDOA and FDOA information calculated by the correlation processor 302 are output to the location point calculation unit 303.

[0021] In FIG. 2, the correlation processor 302-#1 receives the complex signal vector x １ (t) and the complex signal vector x acquired by the signal receiving unit 301-#2 ２ (t), the complex signal vector x １ (t), x ２ By correlation processing between (t), TDOAτ １２（ｉ） and FDOAf １２（ｉ） The correlation processor 302-#1 calculates the information of TDOAτ １２（ｉ） and FDOAf １２（ｉ） The signal indicating the information is output to the orientation point calculation unit 303-#1. The correlation processing unit 302-#2 also outputs the complex signal vector x ２ (t) and the complex signal vector x acquired by the signal receiving unit 301-#3 ３ (t), the complex signal vector x ２ (t), x ３ By correlation processing between (t), TDOAτ ２３（ｊ） and FDOAf ２３（ｊ）The correlation processor 302-#2 calculates the information of TDOAτ ２３（ｊ） and FDOAf ２３（ｊ） The signal indicating the information is output to the orientation point calculation unit 303-#2. Also, the correlation processing unit 302-#3 calculates the complex signal vector x １ (t) and the complex signal vector x acquired by the signal receiving unit 301-#3 ３ (t), the complex signal vector x １ (t), x ３ By correlation processing between (t), TDOAτ １３（ｋ） and FDOAf １３（ｋ） The correlation processor 302-#3 calculates the information of TDOAτ １３（ｋ） and FDOAf １３（ｋ） A signal indicating the information is output to the orientation point calculation unit 303-#3.

[0022] The numbers of peak values ​​of CAF calculated from the received signals between satellites 1-#1 to 1-#3 are N １２ , N ２３ , N １３ Then, i, j, and k are 1≦i≦N １２ , 1≦j≦N ２３ , 1≦k≦N １３ Satisfies the range.

[0023] The orientation point calculation unit 303 performs position location processing using the information on the TDOA and FDOA calculated by the correlation processing unit 302, thereby obtaining an orientation point corresponding to the TDOA and FDOA. A signal indicating the orientation point calculated by this orientation point calculation unit 303 is output to the orientation point accumulation unit 304.

[0024] In FIG. 2, the orientation point calculation unit 303#1 calculates the TDOAτ １２（ｉ） and FDOAf １２（ｉ） By performing position location processing using the information of １２（ｉ） and FDOAf １２（ｉ） The control point p corresponding to １２（ｉ） The orientation point p calculated by the orientation point calculation unit 303-#1 is calculated. １２（ｉ）The signal indicating the TDOAτ calculated by the correlation processing unit 302-#2 is output to the orientation point storage unit 304. ２３（ｊ） and FDOAf ２３（ｊ） By performing position location processing using the information of ２３（ｊ） and FDOAf ２３（ｊ） The control point p corresponding to ２３（ｊ） The orientation point p calculated by the orientation point calculation unit 303-#2 is calculated. ２３（ｊ） The signal indicating the TDOAτ calculated by the correlation processing unit 302-#3 is output to the orientation point storage unit 304. １３（ｋ） and FDOAf １３（ｋ） By performing position location processing using the information of １３（ｋ） and FDOAf １３（ｋ） The control point p corresponding to １３（ｋ） The orientation point p calculated by the orientation point calculation unit 303-#3 is calculated. １３（ｋ） The signal indicating the position is output to the orientation point storage unit 304.

[0025] The orientation point calculation unit 303 calculates an orientation point corresponding to a set of TDOA and FDOA. １２ The orientation point calculation unit 303-#2 calculates N orientation points. ２３ The orientation point calculation unit 303-#3 calculates N orientation points. １３ Calculate the orientation points.

[0026] The orientation point storage unit 304 stores information indicating the orientation points calculated by each orientation point calculation unit 303. This orientation point storage unit 304 continues storage when the storage time determination unit 305 determines that the elapsed storage time has not reached the storage time. On the other hand, when the storage time determination unit 305 determines that the elapsed storage time has reached the storage time, the orientation point storage unit 304 outputs a signal indicating the stored orientation points to the coordinate conversion unit 306.

[0027] In FIG. 2, the orientation point accumulation unit 304 collects the orientation points calculated by the orientation point calculation unit 303-#1, the orientation points calculated by the orientation point calculation unit 303-#2, and the orientation points calculated by the orientation point calculation unit 303-#3 into one, and stores the set of orientation points p ａｌｌ = [p １２（ｉ） , p ２３（ｊ） , p １３（ｋ） If the accumulation time determination unit 305 determines that the elapsed time of accumulation has not reached the accumulation time, the orientation point accumulation unit 304 creates and accumulates p ａｌｌ Continue accumulating p ａｌｌ－Ｔ On the other hand, when the accumulation time determination unit 305 determines that the elapsed time of accumulation has reached the accumulation time, the orientation point accumulation unit 304 updates the accumulated p ａｌｌ－Ｔ to the coordinate conversion unit 306.

[0028] The accumulation time determination unit 305 determines whether the elapsed time of accumulation by the orientation point accumulation unit 304 has reached a preset accumulation time. Specifically, the accumulation time determination unit 305 sets the time when acquisition of the orientation points begins to be 0, measures the elapsed time t from that time, and determines whether the elapsed time has reached a preset accumulation time T.

[0029] 2 illustrates a case where the orientation point storage unit 304 and the storage time determination unit 305 are provided inside the positioning device 3. However, the present invention is not limited to this, and the orientation point storage unit 304 and the storage time determination unit 305 may be provided outside the positioning device 3.

[0030] The coordinate conversion unit 306 converts into latitude and longitude information the control points indicated by the information accumulated for multiple hours by the control point accumulation unit 304. A signal indicating the latitude and longitude information obtained by this coordinate conversion unit 306 is output to the frequency distribution calculation unit 307.

[0031] In FIG. 2, the coordinate conversion unit 306 converts the p stored for multiple hours by the orientation point storage unit 304. ａｌｌ－ＴThe three-dimensional vector information of each control point stored in the coordinate conversion unit 306 is converted into information pall-T-latlon of latitude φ and longitude θ. A signal indicating the information pall-T-latlon of latitude φ and longitude θ obtained by this coordinate conversion unit 306 is output to a frequency distribution calculation unit 307.

[0032] The frequency distribution calculation unit 307 calculates the frequency distribution of the control points based on the latitude and longitude information obtained by the coordinate conversion unit 306. The frequency distribution of the control points is a distribution for evaluating the density of the control points. A signal indicating the frequency distribution calculated by the frequency distribution calculation unit 307 is output to the control point extraction unit 308.

[0033] The control point extraction unit 308 extracts control points included in the area with the maximum frequency from the frequency distribution based on the frequency distribution calculated by the frequency distribution calculation unit 307. The control points extracted by the control point extraction unit 308 are candidates for control points originating from the target radio wave source 10. A signal indicating the control point extracted by the control point extraction unit 308 is output to the error ellipse calculation unit 309.

[0034] In FIG. 2, based on the frequency distribution calculated by the frequency distribution calculation unit 307, the control point extraction unit 308 extracts the control point p corresponding to the set of satellites 1-#1 to 1-#3 as the control point included in the area with the maximum frequency from the frequency distribution. ｅｘｔ－１２ , p ｅｘｔ－２３ , p ｅｘｔ－１３ Extract.

[0035] The error ellipse calculation unit 309 calculates an error ellipse, which is an area where the orientation point may exist, for each pair of satellites 1 based on the orientation points extracted by the orientation point extraction unit 308. A signal indicating the error ellipse calculated by this error ellipse calculation unit 309 is output to the common part calculation unit 310.

[0036] In FIG. 2, the error ellipse calculation unit 309 calculates the error ellipse of the orientation point p extracted by the orientation point extraction unit 308. ｅｘｔ－１２ , p ｅｘｔ－２３ , p ｅｘｔ－１３ Based on this, for each set of satellites 1-#1 to 1-#3, the control point p ｅｘｔ－１２ , p ｅｘｔ－２３ , p ｅｘｔ－１３The error ellipse calculation unit 309 calculates an error ellipse, which is an area where the error ellipse may exist. A signal indicating the error ellipse calculated by the error ellipse calculation unit 309 is output to the common part calculation unit 310.

[0037] The common part calculation unit 310 extracts orientation points that exist in overlapping areas, which are the common parts of the error ellipses, based on the error ellipses calculated by the error ellipse calculation unit 309. A signal indicating the orientation points extracted by the common part calculation unit 310 is output to a center of gravity calculation unit 311.

[0038] Based on the orientation points extracted by the common part calculation section 310, the center of gravity calculation section 311 determines the center of gravity of the orientation points as the position of the target radio wave source 10. A signal indicating the position of the target radio wave source 10 estimated by this center of gravity calculation section 311 is output to the outside.

[0039] The error ellipse calculation unit 309, the common part calculation unit 310, and the centroid calculation unit 311 constitute a "position estimation unit that estimates the position of the target radio wave source 10 based on the control points extracted by the control point extraction unit 308." Also, Fig. 2 shows a case where the position estimation unit includes the error ellipse calculation unit 309, the common part calculation unit 310, and the centroid calculation unit 311. However, the present invention is not limited to this, and the position estimation unit may have any configuration that can estimate the position of the target radio wave source 10 based on the control points extracted by the control point extraction unit 308.

[0040] Next, an example of operation of the positioning device 3 according to the first embodiment shown in FIG. 2 will be described with reference to FIG. 3 . In the example of operation of the positioning device 3 according to the first embodiment shown in FIG. 2 , as shown in FIG. 3 , the signal receiving unit 301 first acquires a complex signal vector of a signal received by a corresponding satellite 1 based on a signal received by a corresponding terrestrial station antenna 2 (step ST101). Specifically, the signal receiving unit 301 first performs various signal processing, such as amplification, band-pass filtering, and frequency conversion, on the RF (radio frequency) output of the terrestrial station antenna 2 to generate an analog signal. This analog signal is a complex signal having an in-phase component and a quadrature component. The signal receiving unit 301 then converts this analog signal into a received signal, which is a digital complex signal, to acquire the complex signal vector. The signal indicating the complex signal vector acquired by the signal receiving unit 301 is output to the correlation processing unit 302.

[0041] In FIG. 2, the signal receiving unit 301-#1 receives the complex signal vector x of the signal received by the satellite 1-#1 based on the signal received by the ground station antenna 2-#1. １ (t) is acquired by the signal receiving unit 301-#1. １ The signal indicating (t) is output to correlation processors 302-#1 and 302-#3. Furthermore, signal receiver 301-#2 calculates the complex signal vector x of the signal received by satellite 1-#2 based on the signal received by ground station antenna 2-#2. ２ (t) is acquired by the signal receiving unit 301-#2. ２ The signal indicating (t) is output to correlation processors 302-#1 and 302-#2. Furthermore, signal receiver 301-#3 calculates the complex signal vector x of the signal received by satellite 1-#3 based on the signal received by ground station antenna 2-#3. ３ (t) is acquired by the signal receiving unit 301-#3. ３ A signal indicating (t) is output to correlation processing section 302-#2 and correlation processing section 302-#3.

[0042] Next, the correlation processing unit 302 calculates TDOA and FDOA information by correlation processing between the complex signal vectors based on the complex signal vectors acquired by each signal receiving unit 301 (step ST102). Specifically, the correlation processing unit 302 calculates TDOA and FDOA information by extracting CAF peak values ​​according to the method described in Non-Patent Document 1 as the correlation processing between the complex signal vectors. Note that if the target radio wave source 10 is a radar wave source, there will be multiple CAF peak values, and as a result, multiple pieces of TDOA and FDOA information will be calculated. The signals indicating the TDOA and FDOA information calculated by the correlation processing unit 302 are output to the location point calculation unit 303.

[0043] In FIG. 2, the correlation processor 302-#1 receives the complex signal vector x １ (t) and the complex signal vector x acquired by the signal receiving unit 301-#2 ２ (t), the complex signal vector x １ (t), x ２ By correlation processing between (t), TDOAτ １２（ｉ） and FDOAf １２（ｉ） The correlation processor 302-#1 calculates the information of TDOAτ １２（ｉ） and FDOAf １２（ｉ） The signal indicating the information is output to the orientation point calculation unit 303-#1. The correlation processing unit 302-#2 also outputs the complex signal vector x ２ (t) and the complex signal vector x acquired by the signal receiving unit 301-#3 ３ (t), the complex signal vector x ２ (t), x ３ By correlation processing between (t), TDOAτ ２３（ｊ） and FDOAf ２３（ｊ） The correlation processor 302-#2 calculates the information of TDOAτ ２３（ｊ） and FDOAf ２３（ｊ） The signal indicating the information is output to the orientation point calculation unit 303-#2. Also, the correlation processing unit 302-#3 calculates the complex signal vector x １(t) and the complex signal vector x acquired by the signal receiving unit 301-#3 ３ (t), the complex signal vector x １ (t), x ３ By correlation processing between (t), TDOAτ １３（ｋ） and FDOAf １３（ｋ） The correlation processor 302-#3 calculates the information of TDOAτ １３（ｋ） and FDOAf １３（ｋ） A signal indicating the information is output to the orientation point calculation unit 303-#3.

[0044] Next, the orientation point calculation unit 303 performs position location processing using the information on the TDOA and FDOA calculated by the correlation processing unit 302, thereby obtaining an orientation point corresponding to the TDOA and FDOA (step ST103). A signal indicating the orientation point calculated by the orientation point calculation unit 303 is output to the orientation point accumulation unit 304.

[0045] In FIG. 2, the orientation point calculation unit 303#1 calculates the TDOAτ １２（ｉ） and FDOAf １２（ｉ） By performing position location processing using the information of １２（ｉ） and FDOAf １２（ｉ） The control point p corresponding to １２（ｉ） Specifically, the orientation point calculation unit 303-#1 calculates the orientation point p by solving simultaneous equations using the following expressions (1), (2), and (7): １２（ｉ） The orientation point p calculated by the orientation point calculation unit 303-#1 is calculated. １２（ｉ） The signal indicating the TDOAτ calculated by the correlation processing unit 302-#2 is output to the orientation point storage unit 304. ２３（ｊ） and FDOAf ２３（ｊ） By performing position location processing using the information of ２３（ｊ） and FDOAf ２３（ｊ） The control point p corresponding to ２３（ｊ） Specifically, the orientation point calculation unit 303-#1 calculates the orientation point p by solving simultaneous equations based on the following expressions (3), (4), and (7): ２３（ｊ） The orientation point p calculated by the orientation point calculation unit 303-#2 is calculated.２３（ｊ） The signal indicating the TDOAτ calculated by the correlation processing unit 302-#3 is output to the orientation point storage unit 304. １３（ｋ） and FDOAf １３（ｋ） By performing position location processing using the information of １３（ｋ） and FDOAf １３（ｋ） The control point p corresponding to １３（ｋ） Specifically, the orientation point calculation unit 303-#1 calculates the orientation point p by solving simultaneous equations using the following expressions (5), (6), and (7). １３（ｋ） The orientation point p calculated by the orientation point calculation unit 303-#3 is calculated. １３（ｋ） The signal indicating the position is output to the orientation point storage unit 304.

[0046] In the formulas (1) to (7), c represents the speed of light, and p ｓ１ indicates the position vector of satellite 1-#1, and p ｓ２ indicates the position vector of satellite 1-#2, and p ｓ３ indicates the position vector of satellite 1-#3, and v ｓ１ indicates the velocity vector of satellite 1-#1, and v ｓ２ indicates the velocity vector of satellite 1-#2, and v ｓ３ indicates the velocity vector of satellite 1-#3, and R Ｅ indicates the radius of the Earth when it is considered as a sphere. ０ denotes the center frequency of the received signal.

[0047] The method for solving the simultaneous equations includes a method for finding a solution through iterative calculations such as Newton's method or steepest descent method, and a method for finding the roots of a polynomial as described in Non-Patent Document 3. The control point calculation unit 303 may use either method. K C. Ho and Y T Chan, "Geolocation of a known altitude object from TDOA and FDOA measurements" in IEEE Transactions on Aerospace and Electronic Systems, vol. 33, no. 3, pp. 770-783, July 1997

[0048] Next, the orientation point accumulation unit 304 accumulates information indicating the orientation points calculated by each orientation point calculation unit 303 for a certain period of time (step ST104). That is, the orientation point accumulation unit 304 continues accumulation if the accumulation time determination unit 305 determines that the elapsed time of accumulation has not reached the accumulation time. On the other hand, if the accumulation time determination unit 305 determines that the elapsed time of accumulation has reached the accumulation time, the orientation point accumulation unit 304 outputs a signal indicating the accumulated orientation points to the coordinate conversion unit 306.

[0049] In FIG. 2, the orientation point accumulation unit 304 collects the orientation points calculated by the orientation point calculation unit 303-#1, the orientation points calculated by the orientation point calculation unit 303-#2, and the orientation points calculated by the orientation point calculation unit 303-#3 into one, and stores the set of orientation points p ａｌｌ = [p １２（ｉ） , p ２３（ｊ） , p １３（ｋ） Then, when the accumulation time determination unit 305 determines that the elapsed time of accumulation has not reached the accumulation time (when t<T), the orientation point accumulation unit 304 creates p ａｌｌ Continue accumulating p ａｌｌ－Ｔ On the other hand, when the accumulation time determination unit 305 determines that the elapsed accumulation time t has reached the accumulation time T (when t≧T), the orientation point accumulation unit 304 updates the accumulated p ａｌｌ－Ｔ to the coordinate conversion unit 306.

[0050] Next, the coordinate conversion unit 306 converts the control point indicated by the information accumulated for multiple hours by the control point accumulation unit 304 into latitude and longitude information (step ST105). A signal indicating the latitude and longitude information obtained by the coordinate conversion unit 306 is output to the frequency distribution calculation unit 307.

[0051] In FIG. 2, the coordinate conversion unit 306 converts the p stored for multiple hours by the orientation point storage unit 304. ａｌｌ－Ｔ The three-dimensional vector information of each control point stored in the coordinate conversion unit 306 is converted into information pall-T-latlon of latitude φ and longitude θ. A signal indicating the information pall-T-latlon of latitude φ and longitude θ obtained by this coordinate conversion unit 306 is output to a frequency distribution calculation unit 307.

[0052] Next, the frequency distribution calculation unit 307 calculates the frequency distribution of the orientation points based on the latitude and longitude information obtained by the coordinate conversion unit 306 (step ST106). A signal indicating the frequency distribution calculated by the frequency distribution calculation unit 307 is output to the orientation point extraction unit 308.

[0053] At this time, the frequency distribution calculation unit 307 creates a frequency distribution such as that shown in Fig. 4. Specifically, in the frequency distribution, the latitude φ direction is divided into M grids, the longitude θ direction is divided into N grids, and for each area (hereinafter referred to as a cell) defined by each grid, the number of orientation points included in that area is stored.

[0054] Next, the control point extraction unit 308 extracts a control point included in the area with the maximum frequency from the frequency distribution calculated by the frequency distribution calculation unit 307 (step ST107). The control point extracted by the control point extraction unit 308 is a candidate for a control point originating from the unknown target radio wave source 10. A signal indicating the control point extracted by the control point extraction unit 308 is output to the error ellipse calculation unit 309.

[0055] In FIG. 2, based on the frequency distribution calculated by the frequency distribution calculation unit 307, the control point extraction unit 308 extracts the control point p corresponding to the set of satellites 1-#1 to 1-#3 as the control point included in the area with the maximum frequency from the frequency distribution. ｅｘｔ－１２ , p ｅｘｔ－２３ , p ｅｘｔ－１３ Extract.

[0056] For example, as shown in FIG. 5, in the frequency distribution calculated by the frequency distribution calculation unit 307, the region with the maximum frequency is indicated by the reference numeral 51 (Δθ ４ , Δφ ６ ), the orientation point extraction unit 308 extracts the orientation point included in the cell.

[0057] Here, the reason why the control point extraction unit 308 extracts a control point included in the region with the highest frequency will be explained. When viewed at a single time, it is difficult to determine whether a control point calculated from a signal acquired by a radar wave source or the like is derived from the true target radio wave source 10 or is an ambiguity. However, as shown in FIG. 6 , when the accumulated results of control points over multiple time periods are viewed, the ambiguity fluctuates in accordance with the motion of the satellite 1, while the true target radio wave source 10 actually exists at that location, so the control point appears in the same location regardless of the motion of the satellite 1. Even if the target radio wave source 10 is moving, the speed is sufficiently smaller than the speed of the orbiting satellite 1. As a result, when viewed over multiple time periods, the behavior of the position fluctuation of the control point differs depending on whether it is derived from the target radio wave source 10 or an ambiguity. If it is derived from the target radio wave source 10, it exhibits characteristics that are relatively close to a fixed point. In FIG. 6 , reference numeral 61 denotes a control point derived from the target radio wave source 10, and reference numeral 62 denotes an ambiguity control point. In the positioning device 3 according to the first embodiment, by using this characteristic, it becomes possible to extract the location point originating from the target radio wave source 10 without using azimuth information.

[0058] Next, the error ellipse calculation unit 309 calculates an error ellipse, which is an area where the orientation point may exist, for each pair of satellites 1 based on the orientation points extracted by the orientation point extraction unit 308 (step ST108). A signal indicating the error ellipse calculated by the error ellipse calculation unit 309 is output to the common part calculation unit 310.

[0059] In FIG. 2, the error ellipse calculation unit 309 calculates the error ellipse of the orientation point p extracted by the orientation point extraction unit 308. ｅｘｔ－１２ , p ｅｘｔ－２３ , p ｅｘｔ－１３ Based on this, for each set of satellites 1-#1 to 1-#3, the control point p ｅｘｔ－１２ , p ｅｘｔ－２３ , p ｅｘｔ－１３ The error ellipse calculation unit 309 calculates an error ellipse, which is an area where the error ellipse may exist. A signal indicating the error ellipse calculated by the error ellipse calculation unit 309 is output to the common part calculation unit 310.

[0060] Specifically, first, the error ellipse calculation unit 309 calculates an error covariance matrix R from each orientation point as shown in the following equations (8) to (10).１２ , R ２３ , R １３ In equations (8) to (10), p(bar) ｅｘｔ－１２ Ha p ｅｘｔ－１２ indicates the center of gravity of p(bar) ｅｘｔ－２３ Ha p ｅｘｔ－２３ indicates the center of gravity of p(bar) ｅｘｔ－１３ Ha p ｅｘｔ－１３ Also, γ ２ is a χ with two degrees of freedom ２ It is determined by a square distribution, and the probability of existence of the orientation point changes depending on the value, as shown in FIG.

[0061] Next, the error ellipse calculation unit 309 calculates the axis length σ of the ellipse from the components of each covariance matrix as shown in the following equations (11) to (19). ｘ１２ , σ ｙ１２ , σ ｘ２３ , σ ｙ２３ , σ ｘ１３ , σ ｙ１３ and the slope φ from the origin １２ , φ ２３ , φ １３ Ask for.

[0062] Next, the error ellipse calculation unit 309 calculates the axis length σ of the calculated ellipse using the following equations (20) to (28). ｘ１２ , σ ｙ１２ , σ ｘ２３ , σ ｙ２３ , σ ｘ１３ , σ ｙ１３ and the slope φ from the origin １２ , φ ２３ , φ １３ The three constants that determine the equation of the ellipse are calculated for each ellipse using the formulas (20) to (28). １２ , B １２ , C １２ Ha p ｅｘｔ－１２ indicates the variables that determine the equation of the error ellipse that indicates the region where ２３ , B ２３ , C ２３ Ha p ｅｘｔ－２３ indicates the variables that determine the equation of the error ellipse that indicates the region where １３ , B １３ , C１３ Ha p ｅｘｔ－１３ The variables determine the equation of the error ellipse that indicates the region where the error may exist.

[0063] By calculating the constants of each ellipse, the equations of the ellipse in the latitude and longitude directions can be expressed as the following equations (29) to (31). Note that in equations (29) to (31), θ (bar) １２ HAp (bar) ｅｘｔ－１２ and θ (bar) indicates the longitude coordinate of ２３ HAp (bar) ｅｘｔ－２３ and θ (bar) indicates the longitude coordinate of １３ HAp (bar) ｅｘｔ－１３ and φ (bar) １２ HAp (bar) ｅｘｔ－１２ latitudinal coordinate of , and φ (bar) ２３ HAp (bar) ｅｘｔ－２３ latitudinal coordinate of , and φ (bar) １３ HAp (bar) ｅｘｔ－１３ Indicates the latitude coordinate of.

[0064] Next, the error ellipse calculation unit 309 calculates the information on the ellipse equations expressed by the formulas (29), (30), and (31) and the information on the orientation points p extracted by the orientation point extraction unit 308. ｅｘｔ－１２ , p ｅｘｔ－２３ , p ｅｘｔ－１３ to the common part calculation unit 310. An example of the operation of the error ellipse calculation unit 309 at this time is shown in FIG. 8. In FIG. 8, reference numerals 81 to 83 indicate the error ellipses calculated by the error ellipse calculation unit 309.

[0065] Next, the common part calculation unit 310 extracts orientation points that exist in the overlapping area, which is the common part of the error ellipses, based on the error ellipses calculated by the error ellipse calculation unit 309 (step ST109). A signal indicating the orientation points extracted by the common part calculation unit 310 is output to the centroid calculation unit 311.

[0066] In FIG. 2, the common part calculation unit 310 calculates p ｅｘｔ－１２ , p ｅｘｔ－２３ , p ｅｘｔ－１３Among these, only orientation points that satisfy the conditions of the following expressions (32) to (34) are extracted. A signal indicating the orientation point pext-12-23-13 extracted by this common part calculation unit 310 is output to the centroid calculation unit 311.

[0067] The spread of the error ellipse is generally determined by the signal-to-noise ratio (SNR) of the received signal and the physical positional relationship between the satellite 1 and the target radio wave source 10. Therefore, depending on the conditions, the error of a specific ellipse among multiple ellipses may be relatively large. In such a case, evaluation of only the pall-T-latlon extracted by evaluating only the frequency distribution may result in an increase in orientation error due to the influence of orientation points that follow error ellipses with relatively large errors. The processing in this common part calculation unit 310 extracts only orientation points that exist in the common part of the error ellipses, thereby reducing the influence even if an orientation point calculated by a specific satellite 1 has a large error, enabling robust orientation regardless of the conditions. An example of the operation of the common part calculation unit 310 is shown in FIG. 9. In FIG. 9, reference numeral 91 denotes an orientation point extracted by the common part calculation unit 310.

[0068] Next, the center of gravity calculation unit 311 determines the center of gravity of the orientation point extracted by the common part calculation unit 310 as the position of the target radio wave source 10 (step ST110). A signal indicating the position of the target radio wave source 10 estimated by this center of gravity calculation unit 311 is output to the outside.

[0069] In FIG. 2, the centroid calculation unit 311 calculates the centroid of the control point pext-12-23-13 existing in the common part of the error ellipses extracted by the common part calculation unit 310, as the position p ｅｘｔ Let the number of pext-12-23-13 be N ｅｘｔ－１２－２３－１３ Then, p ｅｘｔ can be expressed as the following equation (35).

[0070] In this way, the positioning device 3 according to the first embodiment utilizes the property that when the control points derived from the target radio wave source 10 are accumulated over time and compared with the ambiguities, the control points derived from the target radio wave source 10 exhibit characteristics that are relatively close to fixed points. The positioning device 3 according to the first embodiment then extracts the control point included in the area with the highest frequency from the frequency distribution of the control points acquired over multiple times, and uses this control point to estimate the position of the target radio wave source 10. As a result, the positioning device 3 according to the first embodiment can robustly estimate the position of the target radio wave source 10 without using azimuth information and regardless of the positional relationship of the satellites 1.

[0071] As described above, according to the first embodiment, the positioning device 3 includes a plurality of signal receiving units 301 provided for each of a plurality of satellites 1, each of which acquires a complex signal vector of a signal received by the satellite 1; a correlation processing unit 302 that calculates information on TDOA and FDOA by correlation processing between the complex signal vectors based on the complex signal vectors acquired by the signal receiving units 301; a control point calculation unit 303 that calculates a control point corresponding to the TDOA and FDOA based on the information on the TDOA and FDOA calculated by the correlation processing unit 302; The positioning device 3 according to the first embodiment includes a coordinate conversion unit 306 that converts the control points into latitude and longitude information based on the control points for multiple times calculated by the coordinate conversion unit 303, a frequency distribution calculation unit 307 that calculates a frequency distribution of the control points based on the latitude and longitude information obtained by the coordinate conversion unit 306, a control point extraction unit 308 that extracts control points included in an area with the highest frequency from the frequency distribution based on the frequency distribution calculated by the frequency distribution calculation unit 307, and a position estimation unit that estimates the position of the target radio wave source 10 based on the control points extracted by the control point extraction unit 308. As a result, the positioning device 3 according to the first embodiment can locate the target radio wave source 10 without using direction information, regardless of the type of unknown target radio wave source 10. As a result, the positioning device 3 according to the first embodiment can avoid the increase in hardware size and cost that would be required in the past to install an array antenna for acquiring direction information.

[0072] Embodiment 2 The positioning device 3 according to embodiment 1 is assumed to have a single target radio wave source 10. In contrast, the positioning device 3 according to embodiment 2 illustrates a case where there are multiple target radio wave sources 10.

[0073] Fig. 10 is a block diagram showing a schematic configuration example of a positioning system including a positioning device 3 according to embodiment 2. In the positioning system according to embodiment 1 shown in Fig. 1, there is one target radio wave source 10 to be positioned, whereas in the positioning system according to embodiment 2 shown in Fig. 10, there are a plurality of target radio wave sources 10 to be positioned.

[0074] 11 is a block diagram showing a schematic configuration example of a positioning device 3 according to embodiment 2. In the positioning device 3 according to embodiment 2 shown in Fig. 11, the control point extraction unit 308 is changed to a control point extraction unit 312, and the error ellipse calculation unit 309, the common part calculation unit 310, and the center of gravity calculation unit 311 are each changed from singular to plural.

[0075] The control point extraction unit 312 calculates the number of areas where the frequency is equal to or greater than a threshold from the frequency distribution calculated by the frequency distribution calculation unit 307, and extracts control points included in the areas. In this way, the control point extraction unit 312 calculates the number of target radio wave sources 10, and extracts candidates for control points derived from the target radio wave sources 10. A signal indicating the control points extracted by the control point extraction unit 312 is output to the error ellipse calculation unit 309. In addition, a signal indicating the number calculated by the control point extraction unit 312 is output to the error ellipse calculation unit 309, common part calculation unit 310, and centroid calculation unit 311.

[0076] Furthermore, the error ellipse calculation units 309 operate in parallel in the same number as calculated by the control point extraction unit 312, and calculate an error ellipse, which is an area where the control point may exist, for each pair of satellites 1, based on the control points extracted by the control point extraction unit 312. The operation of calculating the error ellipse by this error ellipse calculation unit 309 is the same as the operation of calculating the error ellipse by the error ellipse calculation unit 309 in embodiment 1.

[0077] Furthermore, the common part calculation units 310 operate in parallel in the same number as calculated by the orientation point extraction unit 312, and extract a plurality of orientation points existing in the common part of the error ellipse based on the error ellipse calculated by the error ellipse calculation unit 309. The operation of calculating the error ellipse by this error ellipse calculation unit 309 is the same as the operation of calculating the error ellipse by the error ellipse calculation unit 309 in the first embodiment.

[0078] Furthermore, the centroid calculation units 311 operate in parallel in the same number as calculated by the orientation point extraction unit 312, and calculate the centroid of the orientation point as the target orientation point based on the orientation point extracted by the common part calculation unit 310. The operation of calculating the error ellipse by this error ellipse calculation unit 309 is the same as the operation of calculating the error ellipse by the error ellipse calculation unit 309 in the first embodiment.

[0079] Next, an example of the operation of the positioning device 3 according to the second embodiment shown in Fig. 11 will be described with reference to Fig. 12. The processing of steps ST201 to ST206 in the positioning device 3 according to the second embodiment shown in Fig. 12 is the same as the processing of steps ST101 to ST106 in the positioning device 3 according to the first embodiment shown in Fig. 3.

[0080] Then, based on the frequency distribution calculated by the frequency distribution calculation unit 307, the control point extraction unit 312 calculates the number of areas where the frequency is equal to or greater than a threshold from the frequency distribution, and extracts control points included in the areas (step ST207). In this way, the control point extraction unit 312 estimates the number of target radio wave sources 10, and extracts candidates for control points derived from the target radio wave sources 10. A signal indicating the control points extracted by the control point extraction unit 312 is output to the error ellipse calculation unit 309. In addition, a signal indicating the number calculated by the control point extraction unit 312 is output to the error ellipse calculation unit 309, common part calculation unit 310, and centroid calculation unit 311.

[0081] Here, the area number in the longitude direction is k, and the area number in the latitude direction is l. In this case, the control point extraction unit 312 calculates, for the frequency distribution calculated by the frequency distribution calculation unit 307, the number N of latitude and longitude areas of the frequency distribution that satisfies the following formula (36): ｔａｒis calculated and the control points included in the area are extracted.

[0082] Then, the positioning device 3 extracts the set of (k, l) extracted by the control point extraction unit 312, that is, (k, l)=(k １ , l １ ), (k ２ , l ２ ), ..., (k Ｎｔａｒ , l Ｎｔａｒ ) for the orientation points extracted by the error ellipse calculation unit 309, the common part calculation unit 310, and the centroid calculation unit 311 perform the process of step ST208, step ST209, and step ST210, respectively, in parallel. ｔａｒ A signal indicating the minute estimation result is simultaneously output.

[0083] In this way, in the positioning device 3 according to the second embodiment, the control point extraction unit 312 is provided after the frequency distribution calculation unit 307 in the first embodiment. This makes it possible for the positioning device 3 according to the second embodiment to handle the case where a plurality of target radio wave sources 10 exist, and to simultaneously output signals indicating the positions of the respective target radio wave sources 10.

[0084] As described above, according to the second embodiment, the positioning device 3 includes a plurality of signal receiving units 301 provided for each of the plurality of satellites 1, each of which acquires a complex signal vector of a signal received by the corresponding satellite 1; a correlation processing unit 302 that calculates information on TDOA and FDOA by correlation processing between the complex signal vectors based on the complex signal vectors acquired by the signal receiving units 301; a control point calculation unit 303 that calculates a control point corresponding to the TDOA and FDOA based on the information on the TDOA and FDOA calculated by the correlation processing unit 302; The positioning device 3 according to the second embodiment includes a coordinate conversion unit 306 that converts the control points into latitude and longitude information based on the control points for a plurality of times output, a frequency distribution calculation unit 307 that calculates a frequency distribution of the control points based on the latitude and longitude information obtained by the coordinate conversion unit 306, a control point extraction unit 312 that calculates the number of areas where the frequency is equal to or greater than a threshold from the frequency distribution based on the frequency distribution calculated by the frequency distribution calculation unit 307 and extracts control points included in the areas, and a position estimation unit that estimates the position of the target radio wave source 10 based on the control points extracted by the control point extraction unit 312. As a result, the positioning device 3 according to the first embodiment has the effect of being able to locate each of the target radio wave sources 10 even when there are a plurality of target radio wave sources 10.

[0085] Third Embodiment In a positioning device 3 according to a third embodiment, a signal from a reference station 11 whose position is known is simultaneously received in addition to a signal from a target radio wave source 10, thereby reducing the influence of time errors, frequency errors, and the like that occur within the satellite 1.

[0086] Fig. 13 is a block diagram showing a schematic configuration example of a positioning system including a positioning device 3 according to embodiment 3. The positioning system according to embodiment 1 shown in Fig. 1 receives only a signal from a target radio wave source 10 that is the object of positioning, whereas the positioning system according to embodiment 3 shown in Fig. 13 receives a signal from a reference station 11 whose position is known in addition to the target radio wave source 10 that is the object of positioning.

[0087] That is, the satellite 1 in the third embodiment receives a signal from the target radio wave source 10 and a signal from the reference station 11. The signal received by the satellite 1 is transmitted to the earth station antenna 2.

[0088] In Figure 13, satellite 1-#1 receives a signal from a target radio wave source 10 and a signal from a reference station 11. The signal received by this satellite 1-#1 is transmitted to ground station antenna 2-#1. Satellite 1-#2 receives a signal from the target radio wave source 10 and a signal from the reference station 11. The signal received by this satellite 1-#2 is transmitted to ground station antenna 2-#2. Satellite 1-#3 receives a signal from the target radio wave source 10 and a signal from the reference station 11. The signal received by this satellite 1-#3 is transmitted to ground station antenna 2-#3.

[0089] 14 is a block diagram showing a schematic configuration example of a positioning device 3 according to embodiment 3. In the positioning device 3 according to embodiment 3 shown in Fig. 14, a plurality of signal separation units 313 and a plurality of difference calculation units 316 are added to the positioning device 3 according to embodiment 1 shown in Fig. 2, the correlation processing unit 302 is changed to a first correlation processing unit 314 and a second correlation processing unit 315, and the orientation point calculation unit 303 is changed to an orientation point calculation unit 317.

[0090] The number of signal separators 313 provided corresponds to the number of satellites 1. FIG. 14 shows a case where three signal separators 313-#1 to 313-#3 are provided as the signal separators 313. The number of difference calculators 316 provided corresponds to the number of pairs of satellites 1. FIG. 14 shows a case where three difference calculators 316-#1 to 316-#3 are provided as the difference calculators 316. Also, in FIG. 14, the first correlation processor 314 has first correlation processors 314-#1 to 314-#3 corresponding to the pairs of satellites 1. Also, in FIG. 14, the second correlation processor 315 has second correlation processors 315-#1 to 315-#3 corresponding to the pairs of satellites 1. Also, in FIG. 14, the orientation point calculator 317 has orientation point calculators 317-#1 to 317-#3 corresponding to the pairs of satellites 1.

[0091] The signal separation unit 313 separates the target signal and the signal from the reference station 11 from the complex signal vector acquired by the corresponding signal receiving unit 301, based on the complex signal vector. The target signal acquired by the signal separation unit 313 is output to the first correlation processing unit 314. The signal from the reference station 11 acquired by the signal separation unit 313 is output to the second correlation processing unit 315.

[0092] In FIG. 14, the signal separator 313-#1 separates the complex signal vector x １（ｔ） Based on this, the complex signal vector x １（ｔ） Then, the target signal x is obtained by using a filter process in the frequency domain. ｔａｒ１（ｔ） and the signal x from the reference station 11 ｒｅｆ１（ｔ） The target signal x obtained by this signal separator 313-#1 is ｔａｒ１（ｔ） is output to the first correlation processor 314-#1 and the first correlation processor 314-#3. Also, the signal x ｒｅｆ１（ｔ） is output to second correlation processing section 315-#1 and second correlation processing section 315-#3. Furthermore, signal separation section 313-#2 outputs complex signal vector x ２（ｔ） Based on this, the complex signal vector x ２（ｔ） Then, the target signal x is obtained by using a filter process in the frequency domain. ｔａｒ２（ｔ） and the signal x from the reference station 11 ｒｅｆ２（ｔ） The target signal x obtained by this signal separator 313-#2 is ｔａｒ２（ｔ） is output to the first correlation processor 314-#1 and the first correlation processor 314-#2. Also, the signal x ｒｅｆ２（ｔ） is output to second correlation processing section 315-#1 and second correlation processing section 315-#2. Furthermore, signal separation section 313-#3 outputs complex signal vector x ３（ｔ） Based on this, the complex signal vector x ３（ｔ） Then, the target signal x is obtained by using a filter process in the frequency domain.ｔａｒ３（ｔ） and the signal x from the reference station 11 ｒｅｆ３（ｔ） The target signal x obtained by this signal separator 313-#3 is ｔａｒ３（ｔ） is output to the first correlation processor 314-#2 and the first correlation processor 314-#3. Also, the signal x ｒｅｆ３（ｔ） are output to second correlation processing units 315-#2 and 315-#3.

[0093] The first correlation processor 314 calculates TDOA and FDOA information by correlation processing between the target signals based on the target signals obtained by each signal separator 313. Specifically, the first correlation processor 314 calculates TDOA and FDOA information by extracting CAF peak values ​​according to the method described in Non-Patent Document 1 as the correlation processing between the target signals. Note that if the target radio wave source 10 is a radar wave source, there will be multiple CAF peak values, and as a result, multiple pieces of TDOA and FDOA information will be calculated. Signals indicating the TDOA and FDOA information calculated by the first correlation processor 314 are output to the difference calculator 316.

[0094] In FIG. 14, the first correlation processor 314-#1 extracts the target signal x obtained by the signal separator 313-#1. ｔａｒ１（ｔ） and the target signal x obtained by the signal separation unit 313-#2 ｔａｒ２（ｔ） Based on this, the target signal x ｔａｒ１（ｔ） , x ｔａｒ２（ｔ） By correlation processing between １２（ｉ） and FDOAf １２（ｉ） The TDOAτ calculated by the first correlation processor 314-#1 is １２（ｉ） and FDOAf １２（ｉ） The signal indicating the information is output to the difference calculation section 316-#1. The first correlation processing section 314-#2 also calculates the target signal x obtained by the signal separation section 313-#2. ｔａｒ２（ｔ） and the target signal x obtained by the signal separation unit 313-#3 ｔａｒ３（ｔ） Based on this, the target signal x ｔａｒ２（ｔ） , x ｔａｒ３（ｔ） By correlation processing between ２３（ｊ）and FDOAf ２３（ｊ） The information of the TDOAτ calculated by the first correlation processor 314-#2 is ２３（ｊ） and FDOAf ２３（ｊ） The signal indicating the information is output to the difference calculation section 316-#2. The first correlation processing section 314-#3 also calculates the target signal x obtained by the signal separation section 313-#1. ｔａｒ１（ｔ） and the target signal x obtained by the signal separation unit 313-#3 ｔａｒ３（ｔ） Based on this, the target signal x ｔａｒ１（ｔ） , x ｔａｒ３（ｔ） By correlation processing between １３（ｋ） and FDOAf １３（ｋ） The TDOAτ calculated by the first correlation processor 314-#3 is １３（ｋ） and FDOAf １３（ｋ） The signal indicating this information is output to the difference calculation section 316-#3.

[0095] The second correlation processor 315 calculates TDOA and FDOA information by correlation processing between the signals from the reference station 11 obtained by each signal separator 313. Specifically, the second correlation processor 315 calculates TDOA and FDOA information by extracting peak values ​​of the CAF according to the method described in Non-Patent Document 1 as the correlation processing between the signals. Note that if the reference station 11 is a radar wave source, multiple peaks will exist in the CAF, but since its position is known, it is possible to extract the TDOA and FDOA originating from the reference station 11. The signals indicating the TDOA and FDOA information calculated by the second correlation processor 315 are output to the difference calculator 316.

[0096] In FIG. 14, the second correlation processor 315-#1 separates the signal x from the reference station 11 obtained by the signal separator 313-#1. ｒｅｆ１（ｔ） and the signal x from the reference station 11 obtained by the signal separator 313-#2 ｒｅｆ２（ｔ） Based on this, the signal x ｒｅｆ１（ｔ） , x ｒｅｆ２（ｔ） By correlation processing between １２ｒ and FDOAf １２ｒThe information of the TDOAτ calculated by the second correlation processor 315-#1 is １２ｒ and FDOAf １２ｒ The signal indicating the information is output to the difference calculation unit 316-#1. The second correlation processing unit 315-#2 also calculates the signal x from the reference station 11 obtained by the signal separation unit 313-#2. ｒｅｆ２（ｔ） and the signal x from the reference station 11 obtained by the signal separator 313-#3 ｒｅｆ３（ｔ） Based on this, the signal x ｒｅｆ２（ｔ） , x ｒｅｆ３（ｔ） By correlation processing between ２３ｒ and FDOAf ２３ｒ The information of the TDOAτ calculated by the second correlation processor 315-#2 is ２３ｒ and FDOAf ２３ｒ The signal indicating the information is output to the difference calculation unit 316-#2. The second correlation processing unit 315-#3 also calculates the signal x from the reference station 11 obtained by the signal separation unit 313-#1. ｒｅｆ１（ｔ） and the signal x from the reference station 11 obtained by the signal separator 313-#3 ｒｅｆ３（ｔ） Based on this, the signal x ｒｅｆ１（ｔ） , x ｒｅｆ３（ｔ） By correlation processing between １３ｒ and FDOAf １３ｒ The TDOAτ calculated by the second correlation processor 315-#3 is １３ｒ and FDOAf １３ｒ The signal indicating this information is output to the difference calculation section 316-#3.

[0097] The difference calculation unit 316 calculates the difference between the TDOAs and the difference between the FDOAs based on the information on the TDOAs and FDOAs calculated by the first correlation processing unit 314 and the information on the TDOAs and FDOAs calculated by the second correlation processing unit 315. A signal indicating the difference calculated by this difference calculation unit 316 is output to the corresponding orientation point calculation unit 317.

[0098] In FIG. 14, the difference calculation unit 316-#1 calculates the TDOA calculated by the first correlation processing unit 314-#1. １２（ｉ） and the TDOAτ calculated by the second correlation processor 315-#1.１２ｒ The difference τ １２－ｒ（ｉ） , and the FDOA calculated by the first correlation processor 314-#1 １２（ｉ） and FDOAf calculated by the second correlation processor 315-#1 １２ｒ The difference f １２－ｒ（ｉ） The difference τ calculated by this difference calculation unit 316-#1 １２－ｒ（ｉ） , f １２－ｒ（ｉ） The signal indicating the TDOA calculated by the first correlation processor 314-#2 is output to the orientation point calculation unit 317-#1. ２３（ｊ） and the TDOAτ calculated by the second correlation processor 315-#2. ２３ｒ The difference τ ２３－ｒ（ｊ） , and the FDOA calculated by the first correlation processor 314-#2 ２３（ｊ） and FDOAf calculated by the second correlation processor 315-#2 ２３ｒ The difference f ２３－ｒ（ｊ） The difference τ calculated by this difference calculation unit 316-#2 ２３－ｒ（ｉ） , f ２３－ｒ（ｉ） The signal indicating the TDOA calculated by the first correlation processor 314-#3 is output to the orientation point calculation unit 317-#2. １３（ｋ） and the TDOAτ calculated by the second correlation processor 315-#3. １３ｒ The difference τ １３－ｒ（ｋ） , and the FDOA calculated by the first correlation processor 314-#3 １３（ｋ） and FDOAf calculated by the second correlation processor 315-#3 １３ｒ The difference f １３－ｒ（ｋ） The difference τ calculated by this difference calculation unit 316-#3 １３－ｒ（ｉ） , f １３－ｒ（ｉ） A signal indicating this is output to the orientation point calculation unit 317-#3.

[0099] The orientation point calculation unit 317 performs position orientation processing using the difference calculated by the difference calculation unit 316, thereby determining the orientation point corresponding to the difference. A signal indicating the orientation point calculated by this orientation point calculation unit 317 is output to the orientation point accumulation unit 304.

[0100] In FIG. 14, the orientation point calculation unit 317-#1 calculates the difference τ １２－ｒ（ｉ） , f １２－ｒ（ｉ） By performing the position location process using １２（ｉ） The orientation point p calculated by the orientation point calculation unit 317-#1 is calculated. １２（ｉ） The signal indicating the difference τ ２３－ｒ（ｊ） , f ２３－ｒ（ｊ） By performing the position location process using ２３（ｊ） The orientation point p calculated by the orientation point calculation unit 317-#2 is calculated. ２３（ｊ） The signal indicating the difference τ １３－ｒ（ｋ） , f １３－ｒ（ｋ） By performing the position location process using １３（ｋ） The orientation point p calculated by the orientation point calculation unit 317-#3 is calculated. １３（ｋ） The signal indicating the position is output to the orientation point storage unit 304.

[0101] Next, an example of the operation of the positioning device 3 according to the third embodiment shown in FIG. 14 will be described with reference to FIG.

[0102] The processing of steps ST301 and ST307 to ST313 in the positioning device 3 according to the third embodiment shown in FIG. 15 is the same as the processing of steps ST101 and ST104 to ST110 in the positioning device 3 according to the first embodiment shown in FIG.

[0103] Then, based on the complex signal vector acquired by the corresponding signal receiving unit 301, the signal separating unit 313 separates the target signal and the signal from the reference station 11 from the complex signal vector (step ST302). The target signal acquired by this signal separating unit 313 is output to the first correlation processing unit 314. Furthermore, the signal from the reference station 11 acquired by the signal separating unit 313 is output to the second correlation processing unit 315.

[0104] In FIG. 14, the signal separator 313-#1 separates the complex signal vector x １（ｔ） Based on this, the complex signal vector x １（ｔ） Then, the target signal x is obtained by using a filter process in the frequency domain. ｔａｒ１（ｔ） and the signal x from the reference station 11 ｒｅｆ１（ｔ） The target signal x obtained by this signal separator 313-#1 is ｔａｒ１（ｔ） is output to the first correlation processor 314-#1 and the first correlation processor 314-#3. Also, the signal x ｒｅｆ１（ｔ） is output to second correlation processing section 315-#1 and second correlation processing section 315-#3. Furthermore, signal separation section 313-#2 outputs complex signal vector x ２（ｔ） Based on this, the complex signal vector x ２（ｔ） Then, the target signal x is obtained by using a filter process in the frequency domain. ｔａｒ２（ｔ） and the signal x from the reference station 11 ｒｅｆ２（ｔ） The target signal x obtained by this signal separator 313-#2 is ｔａｒ２（ｔ） is output to the first correlation processor 314-#1 and the first correlation processor 314-#2. Also, the signal x ｒｅｆ２（ｔ） is output to second correlation processing section 315-#1 and second correlation processing section 315-#2. Furthermore, signal separation section 313-#3 outputs complex signal vector x ３（ｔ） Based on this, the complex signal vector x ３（ｔ） Then, the target signal x is obtained by using a filter process in the frequency domain. ｔａｒ３（ｔ） and the signal x from the reference station 11 ｒｅｆ３（ｔ） The target signal x obtained by this signal separator 313-#3 is ｔａｒ３（ｔ） is output to the first correlation processor 314-#2 and the first correlation processor 314-#3. Also, the signal x ｒｅｆ３（ｔ）are output to second correlation processing units 315-#2 and 315-#3.

[0105] Next, the first correlation processing unit 314 calculates TDOA and FDOA information by correlation processing between the target signals based on the target signals obtained by each signal separation unit 313 (step ST303). Specifically, the first correlation processing unit 314 calculates TDOA and FDOA information by extracting CAF peak values ​​according to the method described in Non-Patent Document 1 as the correlation processing between the target signals. Note that if the target radio wave source 10 is a radar wave source, there will be multiple CAF peak values, and as a result, multiple pieces of TDOA and FDOA information will be calculated. The signals indicating the TDOA and FDOA information calculated by the first correlation processing unit 314 are output to the difference calculation unit 316.

[0106] In FIG. 14, the first correlation processor 314-#1 extracts the target signal x obtained by the signal separator 313-#1. ｔａｒ１（ｔ） and the target signal x obtained by the signal separation unit 313-#2 ｔａｒ２（ｔ） Based on this, the target signal x ｔａｒ１（ｔ） , x ｔａｒ２（ｔ） By correlation processing between １２（ｉ） and FDOAf １２（ｉ） The TDOAτ calculated by the first correlation processor 314-#1 is １２（ｉ） and FDOAf １２（ｉ） The signal indicating the information is output to the difference calculation section 316-#1. The first correlation processing section 314-#2 also calculates the target signal x obtained by the signal separation section 313-#2. ｔａｒ２（ｔ） and the target signal x obtained by the signal separation unit 313-#3 ｔａｒ３（ｔ） Based on this, the target signal x ｔａｒ２（ｔ） , x ｔａｒ３（ｔ） By correlation processing between ２３（ｊ） and FDOAf ２３（ｊ） The information of the TDOAτ calculated by the first correlation processor 314-#2 is ２３（ｊ） and FDOAf ２３（ｊ）The signal indicating the information is output to the difference calculation section 316-#2. The first correlation processing section 314-#3 also calculates the target signal x obtained by the signal separation section 313-#1. ｔａｒ１（ｔ） and the target signal x obtained by the signal separation unit 313-#3 ｔａｒ３（ｔ） Based on this, the target signal x ｔａｒ１（ｔ） , x ｔａｒ３（ｔ） By correlation processing between １３（ｋ） and FDOAf １３（ｋ） The TDOAτ calculated by the first correlation processor 314-#3 is １３（ｋ） and FDOAf １３（ｋ） The signal indicating this information is output to the difference calculation section 316-#3.

[0107] Furthermore, the second correlation processing unit 315 calculates TDOA and FDOA information by performing correlation processing between the signals from the reference station 11 obtained by each signal separation unit 313 (step ST304). Specifically, the second correlation processing unit 315 calculates TDOA and FDOA information by extracting peak values ​​of the CAF according to the method described in Non-Patent Document 1 as the correlation processing between the signals. Note that if the reference station 11 is a radar wave source, multiple peaks will exist in the CAF, but since its position is known, it is possible to extract the TDOA and FDOA from the reference station 11. The signals indicating the TDOA and FDOA information calculated by the second correlation processing unit 315 are output to the difference calculation unit 316.

[0108] In FIG. 14, the second correlation processor 315-#1 separates the signal x from the reference station 11 obtained by the signal separator 313-#1. ｒｅｆ１（ｔ） and the signal x from the reference station 11 obtained by the signal separator 313-#2 ｒｅｆ２（ｔ） Based on this, the signal x ｒｅｆ１（ｔ） , x ｒｅｆ２（ｔ） By correlation processing between １２ｒ and FDOAf １２ｒ The information of the TDOAτ calculated by the second correlation processor 315-#1 is １２ｒ and FDOAf １２ｒThe signal indicating the information is output to the difference calculation unit 316-#1. The second correlation processing unit 315-#2 also calculates the signal x from the reference station 11 obtained by the signal separation unit 313-#2. ｒｅｆ２（ｔ） and the signal x from the reference station 11 obtained by the signal separator 313-#3 ｒｅｆ３（ｔ） Based on this, the signal x ｒｅｆ２（ｔ） , x ｒｅｆ３（ｔ） By correlation processing between ２３ｒ and FDOAf ２３ｒ The information of the TDOAτ calculated by the second correlation processor 315-#2 is ２３ｒ and FDOAf ２３ｒ The signal indicating the information is output to the difference calculation unit 316-#2. The second correlation processing unit 315-#3 also calculates the signal x from the reference station 11 obtained by the signal separation unit 313-#1. ｒｅｆ１（ｔ） and the signal x from the reference station 11 obtained by the signal separator 313-#3 ｒｅｆ３（ｔ） Based on this, the signal x ｒｅｆ１（ｔ） , x ｒｅｆ３（ｔ） By correlation processing between １３ｒ and FDOAf １３ｒ The TDOAτ calculated by the second correlation processor 315-#3 is １３ｒ and FDOAf １３ｒ The signal indicating this information is output to the difference calculation section 316-#3.

[0109] Next, the difference calculation unit 316 calculates the difference between the TDOAs and the difference between the FDOAs based on the information on the TDOAs and FDOAs calculated by the first correlation processing unit 314 and the information on the TDOAs and FDOAs calculated by the second correlation processing unit 315 (step ST305). A signal indicating the difference calculated by this difference calculation unit 316 is output to the corresponding orientation point calculation unit 317.

[0110] In FIG. 14, the difference calculation unit 316-#1 calculates the TDOA calculated by the first correlation processing unit 314-#1 as shown in the following equations (37) and (40). １２（ｉ） and the TDOAτ calculated by the second correlation processor 315-#1. １２ｒ The difference τ １２－ｒ（ｉ）, and the FDOA calculated by the first correlation processor 314-#1 １２（ｉ） and FDOAf calculated by the second correlation processor 315-#1 １２ｒ The difference f １２－ｒ（ｉ） The difference τ calculated by this difference calculation unit 316-#1 １２－ｒ（ｉ） , f １２－ｒ（ｉ） The signal indicating the difference is output to the orientation point calculation unit 317-#1. The difference calculation unit 316-#2 calculates the TDOA calculated by the first correlation processing unit 314-#2 as shown in the following equations (38) and (41). ２３（ｊ） and the TDOAτ calculated by the second correlation processor 315-#2. ２３ｒ The difference τ ２３－ｒ（ｊ） , and the FDOA calculated by the first correlation processor 314-#2 ２３（ｊ） and FDOAf calculated by the second correlation processor 315-#2 ２３ｒ The difference f ２３－ｒ（ｊ） The difference τ calculated by this difference calculation unit 316-#2 ２３－ｒ（ｉ） , f ２３－ｒ（ｉ） The signal indicating the difference is output to the orientation point calculation unit 317-#2. The difference calculation unit 316-#3 calculates the TDOA calculated by the first correlation processing unit 314-#3 as shown in the following equations (39) and (42). １３（ｋ） and the TDOAτ calculated by the second correlation processor 315-#3. １３ｒ The difference τ １３－ｒ（ｋ） , and the FDOA calculated by the first correlation processor 314-#3 １３（ｋ） and FDOAf calculated by the second correlation processor 315-#3 １３ｒ The difference f １３－ｒ（ｋ） The difference τ calculated by this difference calculation unit 316-#3 １３－ｒ（ｉ） , f １３－ｒ（ｉ） A signal indicating this is output to the orientation point calculation unit 317-#3.

[0111] As described above, the positioning device 3 according to the third embodiment calculates the difference between the TDOA and the FDOA calculated from two types of signals received from the same satellite 1. This makes it possible for the positioning device 3 according to the third embodiment to reduce offset errors in the TDOA and FDOA caused by the satellite 1, such as signal delays due to circuits within the satellite 1 and frequency transitions due to frequency conversion.

[0112] Next, the orientation point calculation unit 317 performs position orientation processing using the difference calculated by the difference calculation unit 316 to find the orientation point corresponding to the difference (step ST306). A signal indicating the orientation point calculated by this orientation point calculation unit 317 is output to the orientation point accumulation unit 304.

[0113] In FIG. 14, the orientation point calculation unit 317-#1 calculates the difference τ １２－ｒ（ｉ） , f １２－ｒ（ｉ） By performing the position location process using １２（ｉ） Specifically, the orientation point calculation unit 317-#1 solves the simultaneous equations of the following expressions (43), (44), and (7) to obtain the orientation point p １２（ｉ） The orientation point p calculated by the orientation point calculation unit 317-#1 is calculated. １２（ｉ） The signal indicating the difference τ ２３－ｒ（ｊ） , f ２３－ｒ（ｊ） By performing the position location process using ２３（ｊ） Specifically, the orientation point calculation unit 317-#2 solves the simultaneous equations of the following expressions (45), (46), and (7) to obtain the orientation point p ２３（ｊ） The orientation point p calculated by the orientation point calculation unit 317-#2 is calculated. ２３（ｊ） The signal indicating the difference τ １３－ｒ（ｋ） , f １３－ｒ（ｋ） By performing the position location process using １３（ｋ）Specifically, the orientation point calculation unit 317-#3 solves the simultaneous equations of the following expressions (47), (48), and (7) to obtain the orientation point p １３（ｋ） The orientation point p calculated by the orientation point calculation unit 317-#3 is calculated. １３（ｋ） The signal indicating the position is output to the orientation point storage unit 304.

[0114] In addition, in the formulas (43) to (48), f ｒ０ indicates the center frequency of the reference station 11, and p ｒ indicates the position of the reference station 11.

[0115] From equations (43), (44), and (7), the orientation point p １２（ｉ） and then calculate the orientation point p from equations (45), (46), and (7). ２３（ｊ） and then calculate the orientation point p from equations (47), (48), and (7). １３（ｋ） is calculated, the offset error originating from the satellite 1 is reduced more than when the control point calculation unit 303 in Embodiment 1 is used. Therefore, in the positioning device 3 according to Embodiment 3, it is possible to estimate the position of the target radio wave source 10 with higher accuracy in the subsequent processing compared to Embodiment 1.

[0116] In this way, the positioning device 3 according to the third embodiment uses a signal from the reference station 11 whose position is known. This allows the positioning device 3 according to the third embodiment to reduce offset errors related to the TDOA and FDOA originating from the satellite 1, and makes it possible to estimate the position of the target radio wave source 10 with higher accuracy than when the signal from the reference station 11 is not used.

[0117] As described above, according to the third embodiment, the positioning device 3 includes a plurality of signal receiving units 301, each provided for a plurality of satellites 1, for acquiring complex signal vectors of signals received by the satellites 1; a signal separating unit 313, each provided for a respective signal receiving unit 301, for separating a target signal and a signal from a reference station 11 from the complex signal vector acquired by the signal receiving unit 301; a first correlation processing unit 314, each provided for a respective target signal acquired by the signal separating unit 313, for calculating information on TDOA and FDOA by correlation processing between the target signals; a second correlation processing unit 315, each provided for a respective signal from the reference station 11 acquired by the signal separating unit 313, for calculating information on TDOA and FDOA by correlation processing between the signals; The apparatus includes a difference calculation unit 316 that calculates a difference between TDOAs and a difference between FDOAs based on information about the TDOAs and FDOAs calculated by the second correlation processing unit 315; a control point calculation unit 317 that calculates a control point corresponding to the difference based on the difference calculated by the difference calculation unit 316; a coordinate conversion unit 306 that converts the control points into latitude and longitude information based on the control points for a plurality of times calculated by the control point calculation unit 317; a frequency distribution calculation unit 307 that calculates a frequency distribution of the control points based on the latitude and longitude information obtained by the coordinate conversion unit 306; a control point extraction unit 308 that extracts control points included in an area with the maximum frequency from the frequency distribution based on the frequency distribution calculated by the frequency distribution calculation unit 307; and a position estimation unit that estimates the position of the target radio wave source 10 based on the control points extracted by the control point extraction unit 308. As a result, the positioning device 3 according to the third embodiment can estimate the position of the target radio wave source 10 with higher accuracy in addition to the effects of the first embodiment.

[0118] Finally, with reference to FIG. 16, an example of the hardware configuration of the positioning device 3 according to the first to third embodiments will be described.

[0119] 16, the hardware configuration example of the positioning device 3 according to the first embodiment is configured with a signal receiving unit 301 and a signal processing device 31. The signal processing device 31 includes a processor 32, a memory 33, an input interface 34, an output interface 35, and a signal path 36.

[0120] Of the components of the positioning device 3 according to the first embodiment, the correlation processing unit 302, the orientation point calculation unit 303, the orientation point accumulation unit 304, the accumulation time determination unit 305, the coordinate conversion unit 306, the frequency distribution calculation unit 307, the orientation point extraction unit 308, the error ellipse calculation unit 309, the common part calculation unit 310, and the centroid calculation unit 311 may be realized by a processor 32 made up of an LSI (Large Scale Integrated circuit) such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). Alternatively, the correlation processing unit 302, the orientation point calculation unit 303, the orientation point accumulation unit 304, the accumulation time determination unit 305, the coordinate conversion unit 306, the frequency distribution calculation unit 307, the orientation point extraction unit 308, the error ellipse calculation unit 309, the common part calculation unit 310, and the centroid calculation unit 311 may be realized by one or more processors 32 including a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit) that executes a computer program.

[0121] The memory 33 includes, for example, a program memory that stores various programs for implementing the signal processing function in the positioning device 3 according to embodiment 1, a work memory that is used when the processor 32 executes signal processing, and a memory into which data used in the signal processing is expanded. The memory 33 may be a plurality of semiconductor memories such as a ROM (Read Only Memory) and an SDRAM (Synchronous Dynamic Random Access Memory).

[0122] 16 is configured using a single processor 32, but is not limited to this. The signal processing function of the positioning device 3 may be realized using a plurality of processors 32 that operate in cooperation with each other. Any of the correlation processing unit 302, orientation point calculation unit 303, orientation point accumulation unit 304, accumulation time determination unit 305, coordinate conversion unit 306, frequency distribution calculation unit 307, orientation point extraction unit 308, error ellipse calculation unit 309, common part calculation unit 310, and centroid calculation unit 311 may be configured as dedicated hardware.

[0123] 16, a hardware configuration example of the positioning device 3 according to the second embodiment is configured with a signal receiving unit 301 and a signal processing device 31. The signal processing device 31 includes a processor 32, a memory 33, an input interface 34, an output interface 35, and a signal path 36.

[0124] Of the components of the positioning device 3 according to the second embodiment, the orientation point extraction unit 312 may be realized by a processor 32 made up of an LSI such as an ASIC or FPGA, or alternatively, the orientation point extraction unit 312 may be realized by one or more processors 32 including a CPU or GPU that executes a computer program.

[0125] The memory 33 includes, for example, a program memory that stores various programs for realizing the signal processing function of the positioning device 3 according to embodiment 2, a work memory that is used when the processor 32 executes signal processing, and a memory into which data used in the signal processing is expanded. The memory 33 may be a plurality of semiconductor memories such as a ROM and an SDRAM.

[0126] 16, the positioning device 3 is configured using a single processor 32, but is not limited to this. The signal processing function of the positioning device 3 may be realized using a plurality of processors 32 that operate in cooperation with each other. The control point extraction unit 312 may be configured using dedicated hardware.

[0127] The configuration of the positioning device 3 according to the second embodiment is the same as that of the positioning device 3 according to the first embodiment, except for the control point extraction unit 312 .

[0128] 16, a hardware configuration example of the positioning device 3 according to the third embodiment is configured with a signal receiving unit 301 and a signal processing device 31. The signal processing device 31 includes a processor 32, a memory 33, an input interface 34, an output interface 35, and a signal path 36.

[0129] Of the components of the positioning device 3 according to the second embodiment, the signal separation unit 313, the first correlation processing unit 314, the second correlation processing unit 315, the difference calculation unit 316, and the orientation point calculation unit 317 may be realized by a processor 32 made up of an LSI such as an ASIC or an FPGA. Alternatively, the signal separation unit 313, the first correlation processing unit 314, the second correlation processing unit 315, the difference calculation unit 316, and the orientation point calculation unit 317 may be realized by one or more processors 32 including a CPU or GPU that executes a computer program.

[0130] The memory 33 includes, for example, a program memory that stores various programs for implementing the signal processing functions of the positioning device 3 according to the third embodiment, a work memory that is used when the processor 32 executes signal processing, and a memory into which data used in the signal processing is expanded. The memory 33 may be a plurality of semiconductor memories such as a ROM and an SDRAM.

[0131] 16 is configured using a single processor 32, but is not limited to this. The signal processing function of the positioning device 3 may be realized using a plurality of processors 32 that operate in cooperation with each other. Any of the signal separation unit 313, the first correlation processing unit 314, the second correlation processing unit 315, the difference calculation unit 316, and the orientation point calculation unit 317 may be configured using dedicated hardware.

[0132] In addition, the configuration of the positioning device 3 according to embodiment 3 is the same as that of the positioning device 3 according to embodiment 1, except for the signal separation unit 313, the first correlation processing unit 314, the second correlation processing unit 315, the difference calculation unit 316, and the orientation point calculation unit 317.

[0133] It should be noted that the embodiments may be freely combined, or any of the components in each embodiment may be modified, or any of the components in each embodiment may be omitted.

[0134] The positioning device according to the present disclosure is capable of locating an unknown target radio wave source without using directional information, regardless of the type of the target radio wave source, and is suitable for use in positioning devices that locate unknown target radio wave sources.

[0135] 1 Satellite, 2 Ground station antenna, 3 Positioning device, 10 Target radio wave source, 11 Reference station, 31 Signal processing device, 32 Processor, 33 Memory, 34 Input interface, 35 Output interface, 36 Signal path, 301 Signal receiving unit, 302 Correlation processing unit, 303 Control point calculation unit, 304 Control point storage unit, 305 Storage time determination unit, 306 Coordinate conversion unit, 307 Frequency distribution calculation unit, 308 Control point extraction unit, 309 Error ellipse calculation unit, 310 Common part calculation unit, 311 Center of gravity calculation unit, 312 Control point extraction unit, 313 Signal separation unit, 314 First correlation processing unit, 315 Second correlation processing unit, 316 Difference calculation unit, 317 Control point calculation unit.

Claims

Claim 1: A positioning device, comprising: a plurality of signal receiving units provided for each of a plurality of satellites, configured to obtain a complex signal vector of a signal received by the satellite; a correlation processing unit configured to calculate information on TDOA and FDOA by performing correlation processing between the complex signal vectors based on the complex signal vectors obtained by the signal receiving units; a reference point calculation unit configured to calculate a reference point corresponding to the TDOA and FDOA based on the information on TDOA and FDOA calculated by the correlation processing unit; a coordinate conversion unit configured to convert the reference point into information on latitude and longitude based on the reference points for a plurality of time periods calculated by the reference point calculation unit; a frequency distribution calculation unit configured to calculate a frequency distribution of the reference points based on the information on latitude and longitude obtained by the coordinate conversion unit; a reference point extraction unit configured to extract a reference point included in a region having the maximum frequency from the frequency distribution based on the frequency distribution calculated by the frequency distribution calculation unit; a position estimation unit configured to estimate the position of a target radio wave source based on the reference point extracted by the reference point extraction unit, wherein the position estimation unit includes an error ellipse calculation unit configured to calculate, for each set of the satellites, an error ellipse which is a region where the reference point may exist, based on the reference point extracted by the reference point extraction unit; a common part calculation unit configured to extract a reference point existing in a common part of the error ellipses based on the error ellipses calculated by the error ellipse calculation unit; and a centroid calculation unit configured to set the centroid of the reference point as the position of the target radio wave source, based on the reference point extracted by the common part calculation unit. The positioning device is characterized by the above. Claim 2: A positioning device, comprising: a plurality of signal receiving units provided for each of a plurality of satellites, configured to obtain a complex signal vector of a signal received by the satellite; a correlation processing unit configured to calculate information on TDOA and FDOA by performing correlation processing between the complex signal vectors based on the complex signal vectors obtained by the signal receiving units; a reference point calculation unit configured to calculate a reference point corresponding to the TDOA and FDOA based on the information on TDOA and FDOA calculated by the correlation processing unit; a coordinate conversion unit configured to convert the reference point into information on latitude and longitude based on the reference points for a plurality of time periods calculated by the reference point calculation unit; a frequency distribution calculation unit configured to calculate a frequency distribution of the reference points based on the information on latitude and longitude obtained by the coordinate conversion unit; Based on the frequency distribution calculated by the frequency distribution calculation unit, a point extraction unit calculates the number of regions in the frequency distribution where the frequency is equal to or greater than a threshold value, and extracts the reference points included in the regions. A position estimation unit that estimates the position of the target radio wave source based on the reference points extracted by the reference point extraction unit. The position estimation unit Operates in parallel by the number calculated by the reference point extraction unit, and based on the reference points extracted by the reference point extraction unit, for each set of satellites, calculates an error ellipse, which is a region where the reference points may exist. Operates in parallel by the number calculated by the reference point extraction unit, and based on the error ellipses calculated by the error ellipse calculation unit, extracts the reference points existing in the common part of the error ellipses. Operates in parallel by the number calculated by the reference point extraction unit, and has a plurality of centroid calculation units that set the centroid of the reference points as the position of the target radio wave source based on the reference points extracted by the common part calculation unit. A positioning device characterized by the above.

3. A plurality of signal reception units provided for each of a plurality of satellites, and acquiring complex signal vectors of signals received by the satellites. A signal separation unit provided for each of the signal reception units, and separating a target signal and a signal from a reference station from the complex signal vector based on the complex signal vector acquired by the signal reception unit. Based on the target signal obtained by the signal separation unit, a first correlation processing unit calculates information on TDOA and FDOA by performing correlation processing between the target signals. Based on the signal from the reference station obtained by the signal separation unit, a second correlation processing unit calculates information on TDOA and FDOA by performing correlation processing between the signals. Based on the information on TDOA and FDOA calculated by the first correlation processing unit and the information on TDOA and FDOA calculated by the second correlation processing unit, a difference calculation unit calculates the difference between TDOAs and the difference between FDOAs. Based on the difference calculated by the difference calculation unit, a reference point calculation unit calculates a reference point corresponding to the difference. Based on the reference points for a plurality of times calculated by the reference point calculation unit, a coordinate conversion unit converts the reference points into latitude and longitude information. Based on the latitude and longitude information obtained by the coordinate conversion unit, a frequency distribution calculation unit calculates the frequency distribution of the reference points. A calibration point extraction unit that extracts calibration points included in a region with the maximum frequency from the frequency distribution based on the frequency distribution calculated by the frequency distribution calculation unit; A position estimation unit that estimates the position of the target radio wave source based on the calibration points extracted by the calibration point extraction unit, The position estimation unit, An error ellipse calculation unit that calculates an error ellipse, which is a region where the calibration points may exist, for each set of the satellites based on the calibration points extracted by the calibration point extraction unit; A common part calculation unit that extracts calibration points existing in the common part of the error ellipse based on the error ellipse calculated by the error ellipse calculation unit; A centroid calculation unit that sets the centroid of the calibration points as the position of the target radio wave source based on the calibration points extracted by the common part calculation unit. A positioning device characterized by the above.

4. A plurality of steps in which a signal reception unit is provided for each of a plurality of satellites and acquires a complex signal vector of a signal received by the satellite; A step in which a correlation processing unit calculates information on TDOA and FDOA by performing correlation processing between the complex signal vectors based on the complex signal vectors acquired by the signal reception unit; A step in which a calibration point calculation unit calculates calibration points corresponding to the TDOA and FDOA based on the information on TDOA and FDOA calculated by the correlation processing unit; A step in which a coordinate conversion unit converts the calibration points into latitude and longitude information based on the calibration points for a plurality of times calculated by the calibration point calculation unit; A step in which a frequency distribution calculation unit calculates a frequency distribution of calibration points based on the latitude and longitude information obtained by the coordinate conversion unit; A step in which a calibration point extraction unit extracts calibration points included in a region with the maximum frequency from the frequency distribution based on the frequency distribution calculated by the frequency distribution calculation unit; A step in which a position estimation unit estimates the position of the target radio wave source based on the calibration points extracted by the calibration point extraction unit, The position estimation unit, An error ellipse calculation unit that calculates an error ellipse, which is a region where the calibration points may exist, for each set of the satellites based on the calibration points extracted by the calibration point extraction unit; A common part calculation unit that extracts calibration points existing in the common part of the error ellipse based on the error ellipse calculated by the error ellipse calculation unit; A centroid calculation unit that sets the centroid of the calibration points as the position of the target radio wave source based on the calibration points extracted by the common part calculation unit. A positioning method characterized by the above.

5. A plurality of steps in which a signal receiving unit is provided for each of a plurality of satellites, and a complex signal vector of a signal received by the satellite is obtained; A step in which a correlation processing unit calculates information on TDOA and FDOA by performing correlation processing between the complex signal vectors based on the complex signal vectors obtained by the signal receiving unit; A step in which a reference point calculation unit calculates a reference point corresponding to the TDOA and FDOA based on the information on TDOA and FDOA calculated by the correlation processing unit; A step in which a coordinate conversion unit converts the reference point into information on latitude and longitude based on the reference points for a plurality of times calculated by the reference point calculation unit; A step in which a frequency distribution calculation unit calculates a frequency distribution of the reference points based on the information on latitude and longitude obtained by the coordinate conversion unit; A step in which a reference point extraction unit calculates the number of regions in which the frequency is equal to or greater than a threshold value from the frequency distribution based on the frequency distribution calculated by the frequency distribution calculation unit, and extracts the reference points included in the region; A positioning method comprising a step in which a position estimation unit estimates the position of a target radio wave source based on the reference points extracted by the reference point extraction unit, wherein the position estimation unit operates in parallel by the number calculated by the reference point extraction unit, and based on the reference points extracted by the reference point extraction unit, for each set of the satellites, a plurality of error ellipse calculation units that calculate an error ellipse which is a region where the reference point may exist; operates in parallel by the number calculated by the reference point extraction unit, and based on the error ellipse calculated by the error ellipse calculation unit, a plurality of common part calculation units that extract the reference points existing in the common part of the error ellipse; operates in parallel by the number calculated by the reference point extraction unit, and has a plurality of centroid calculation units that set the centroid of the reference points as the position of the target radio wave source based on the reference points extracted by the common part calculation unit characterized by this.

6. A plurality of steps in which a signal receiving unit is provided for each of a plurality of satellites, and a complex signal vector of a signal received by the satellite is obtained; A step in which a signal separation unit is provided for each of the signal receiving units, and based on the complex signal vector obtained by the signal receiving unit, separates a target signal and a signal from a reference station from the complex signal vector; The first correlation processing unit calculates information on TDOA and FDOA by performing correlation processing between the target signals based on the target signals obtained by the signal separation unit. The second correlation processing unit calculates information on TDOA and FDOA by performing correlation processing between the signals based on the signals from the reference stations obtained by the signal separation unit. The difference calculation unit calculates the difference between TDOAs and the difference between FDOAs based on the information on TDOA and FDOA calculated by the first correlation processing unit and the information on TDOA and FDOA calculated by the second correlation processing unit. The reference point calculation unit calculates a reference point corresponding to the difference based on the difference calculated by the difference calculation unit. The coordinate conversion unit converts the reference point into information on latitude and longitude based on the reference points for a plurality of times calculated by the reference point calculation unit. The frequency distribution calculation unit calculates the frequency distribution of the reference points based on the information on latitude and longitude obtained by the coordinate conversion unit. The reference point extraction unit extracts the reference points included in the region with the maximum frequency from the frequency distribution based on the frequency distribution calculated by the frequency distribution calculation unit. The position estimation method includes a step of estimating the position of the target radio wave source based on the reference points extracted by the reference point extraction unit. The position estimation unit includes an error ellipse calculation unit that calculates an error ellipse, which is a region where the reference points may exist, for each set of satellites based on the reference points extracted by the reference point extraction unit. a common part calculation unit that extracts the reference points existing in the common part of the error ellipse based on the error ellipse calculated by the error ellipse calculation unit. and a centroid calculation unit that sets the centroid of the reference points as the position of the target radio wave source based on the reference points extracted by the common part calculation unit. A positioning method characterized by the above.