JP2011085391A - Method and device for measuring position - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure the position of a radio wave emission source by a structure without requiring the measurement of arrival time difference or radio wave arrival direction and without increasing the circuit scale and size. <P>SOLUTION: Moving bodies 1a, 1b each include a function of receiving a radio wave and transmitting a reception signal thereof and a function of obtaining and transmitting position information on the current position, and move at the same velocity in the same direction while holding a constant interval therebetween. A base station communication part 2 receives the reception signal and position information transmitted from the moving bodies. A position information processing part 4 calculates position and velocity information of the moving bodies 1a, 1b upon the signal reception from temporal variation of two pieces of position information output from the base station communication part 2. An emission source position calculation part 6 performs the calculation about the central position of the distance between the moving bodies 1a, 1b when the maximum value of the frequency difference is obtained, and estimates the position of the emission source of the same radio wave received by the moving bodies 1a, 1b on the basis of the calculation result. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a position measuring method and a position measuring apparatus, and more particularly to a position measuring method and a position measuring apparatus for measuring the position of a radio wave emission source.

  For the purpose of radio wave monitoring or the like, a position measuring device that measures the position of a radio wave emission source whose position is unknown from received radio waves is used.

  As such a position measuring device, the position measuring device described in Patent Document 1 simultaneously measures a “frequency difference” and an “arrival time difference” between received signals received by a plurality of mobile receivers, thereby providing a launch source. Seeking the position.

  Patent Document 2 discloses a position measuring device that measures the arrival directions of radio waves at a plurality of different positions and measures the emission source position from the intersection of azimuth lines indicating the direction measurement results.

JP 2006-349470 A JP 2002-267732 A

  In the position measuring device described in Patent Document 1, the bandwidth of the received signal is necessary to measure the arrival time difference. Assuming that the frequency bandwidth is f and the delay time is Δt, the phase change amount Δφ of the received signal is represented by 2πfΔt. Therefore, when the frequency bandwidth f is small (narrow band) and large (wide band), the amount of phase change for the same delay time Δt is larger in the wide band than in the narrow band. For this reason, even a small amount of error is greatly affected in a narrow band compared to a wide band.

  For this reason, in the position measuring device described in Patent Document 1, if the received signal is a narrow-band communication signal or the like, the arrival time difference cannot be measured accurately, so the position cannot be measured accurately, and the position is measured particularly with an unmodulated carrier wave. There is a disadvantage that it can not.

  On the other hand, the position measuring apparatus described in Patent Document 2 that measures the position based on the measurement result of the arrival direction of radio waves requires a plurality of antennas and receivers in order to measure the arrival direction of radio waves, and further reduces errors. In order to achieve this, it is necessary to arrange a large number of antennas, and there is a disadvantage that the circuit scale and dimensions become large.

  The present invention has been made in view of the above points, and does not require measurement of the arrival time difference or radio wave arrival direction, and can measure the position of the radio wave emission source with a configuration that does not increase the circuit scale and dimensions. And it aims at providing a position measuring device.

  In order to achieve the above object, the position measurement method of the present invention is configured such that two mobile bodies moving in the same direction at the same speed at a constant distance receive radio waves from radio wave emission sources. The transmission step of transmitting the received signal, acquiring the position information of the current position of the mobile station and transmitting the position information, and the two units based on the received signal and the position information transmitted by the two mobile units Detection and calculation for detecting the maximum value of the frequency difference between the two received signals received by each mobile body and calculating the position and velocity information of the two mobile bodies at the time of signal reception from the time change of the two positional information And a calculation step for calculating the position of the radio wave emission source based on the maximum value of the frequency difference and the position and velocity information.

  In order to achieve the above object, the position measuring apparatus of the present invention has a function of receiving radio waves and transmitting the received signals, and a function of acquiring and transmitting position information of its current position. The first and second moving bodies that move in the same direction at the same speed while maintaining a constant distance from each other, and receive signals and position information transmitted from the first and second moving bodies, respectively. Frequency difference between the two reception signals received by the first and second mobile units based on the communication means and the reception signals received by the first and second mobile units from the communication unit and the acquired position information. Detecting and calculating means for calculating the position and speed information of the first and second moving bodies at the time of signal reception from the time change of the two position information, and the maximum value and position of the frequency difference Based on speed information and It characterized by having a calculating means for calculating the position of the wave source.

  According to the present invention, even if the received signal is a narrowband signal or only an unmodulated carrier wave, the position of the radio wave emission source can be measured at high speed by simple calculation, and the circuit scale and dimensions can be obtained. Can be realized small.

It is a block diagram of one embodiment of a position measuring device of the present invention. Schematic showing the relationship between the two mobile bodies constituting the position measuring device of the present invention and the radio wave emission source, the relationship between the reception frequency difference and the position of the radio wave emission source in the y-axis direction, the reception frequency difference and x It is a figure which shows the relationship between the center position of the distance between the two mobile bodies of an axial direction. It is a figure which shows an example of the relationship between the distance between two mobile bodies, and a radio wave emission source, and time. It is a figure which shows an example of the time variation | change_quantity of the distance between two mobile bodies and a radio wave emission source. It is a figure which shows an example of the time change of the Doppler frequency of two moving bodies. It is a figure which shows an example of the relationship between the Doppler frequency difference of two moving bodies, and time. It is a figure which shows an example of the relationship between maximum value (DELTA) fmax of a frequency difference, and the position of the y-axis direction of a radio wave emission source.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a block diagram of an embodiment of a position measuring apparatus according to the present invention. As shown in the figure, the position measuring apparatus 10 of this embodiment includes two mobile units 1a and 1b, a base station communication unit 2, a frequency difference detection unit 3, a position information processing unit 4, and a maximum frequency. The difference detection unit 5 and the emission source position calculation unit 6 are configured.

  The two mobile units 1a and 1b receive radio waves independently while moving at the same speed in the same direction at regular intervals, and constitute, for example, a global positioning system (GPS) It has a function of receiving GPS signals from artificial satellites to acquire position information of its current position. In addition, when the two mobile units 1a and 1b receive radio waves, the two mobile units 1a and 1b also have a function of transmitting the received reception signal and a function of transmitting the acquired current position information of the current position.

  The base station communication unit 2 includes the first received signal and the first position information of the mobile unit 1a transmitted from the mobile unit 1a, and the second received signal and the second position information of the mobile unit 1b transmitted from the mobile unit 1b. Are received, signal processed, and output.

  The frequency difference detection unit 3 receives the first and second reception signals output from the base station communication unit 2 as inputs, detects the frequency difference between these reception signals by a known method, and detects the frequency difference. Output a signal. The position information processing unit 4 receives the first and second position information output from the base station communication unit 2 as input, and the position of the mobile bodies 1a and 1b at the time of signal reception from the time change of the position information. And speed information is calculated.

  The maximum frequency difference detection unit 5 receives the frequency difference detection signal output from the frequency difference detection unit 3 as an input, acquires the frequency difference indicated by the frequency difference detection signal at regular time intervals, for example, from the previously acquired frequency difference If the frequency difference acquired this time is larger, it is updated to the frequency difference acquired this time, and if the frequency difference acquired this time is smaller, the maximum frequency difference is detected by a method such as holding the frequency difference acquired last time. To do.

  Based on the maximum frequency difference detected by the maximum frequency difference detection unit 5 and the position and speed information output from the position information processing unit 4, the launch source position calculation unit 6 determines the maximum value of the frequency difference. It is calculated at which position the center position of the distance between the two mobile bodies 1a and 1b was obtained, and the calculation result indicates that the same radio waves received by the two mobile bodies 1a and 1b respectively. Estimate (measure) the position of the launch source. This is because the frequency difference is maximized when the line connecting the center position of the distance between the two mobile bodies 1a and 1b and the radio wave emission source is the line connecting the two mobile bodies 1a and 1b. Based on when it crosses vertically.

  Next, the operation of this embodiment will be described with reference to FIGS. 1 and 2 to 7.

  FIG. 2 (A) is a schematic diagram showing the relationship between the two mobile bodies constituting the position measuring apparatus according to the present invention and the radio wave emission source. In the figure, the same components as those in FIG. As shown in FIG. 2 (A), for example, two moving bodies 1a and 1b, which are aircraft, move in the same direction and at the same speed v at a certain distance d while maintaining a certain altitude. It is assumed that the radio waves from the radio wave emission source 7 at the position (X0, Y0) are received independently.

  In addition, each of the mobile bodies 1a and 1b receives, on the ground, a reception signal of a radio wave from the radio wave emission source 7 and position information of its current position obtained based on a GPS signal received from an artificial satellite constituting the GPS. It is transmitted to a certain base station communication unit 2 (not shown in FIG. 2).

  Here, as shown in FIG. 2, when the distance between the moving body 1a and the radio wave emission source 7 is R1, and the distance between the mobile body 1b and the radio wave emission source 7 is R2, the distances R1 and R2 are expressed by the following equations. The

図３は、２台の移動体１ａ及び１ｂが、同一方向に、一定間隔ｄで、同じ速度ｖで高速に移動するときの電波発射源７との距離Ｒ１、Ｒ２の変化と時間との関係の一例を示す。図３において、実線が時間に対する距離Ｒ１の変化を示し、点線が距離Ｒ２の変化を示す。

FIG. 3 shows the relationship between changes in distances R1 and R2 with respect to the radio wave emission source 7 and time when the two moving bodies 1a and 1b move at high speed at the same speed v in the same direction at a constant interval d. An example is shown. In FIG. 3, a solid line indicates a change in the distance R1 with respect to time, and a dotted line indicates a change in the distance R2.

  Moreover, the time variation of the distances R1 and R2 can be obtained by the following equation by differentiating the equations (1) and (2) with respect to time.

図４は、上記の距離Ｒ１、Ｒ２の時間変化量の一例を示す。図４において、実線がｄＲ１／ｄｔの時間変化量を示し、点線がｄＲ２／ｄｔの時間変化量を示す。

FIG. 4 shows an example of the amount of time change of the distances R1 and R2. In FIG. 4, the solid line indicates the time change amount of dR1 / dt, and the dotted line indicates the time change amount of dR2 / dt.

  The above equations (3) and (4) divided by the wavelength λ of the carrier wave of the radio waves received by the mobile bodies 1a and 1b are Doppler frequencies fd1 and fd2, which are obtained by the following equations.

図５は、上記のドップラー周波数ｆｄ１、ｆｄ２と時間との関係の一例を示す。図５において、実線が時間に対するドップラー周波数ｆｄ１の変化を示し、点線が時間に対するドップラー周波数ｆｄ２の変化を示す。

FIG. 5 shows an example of the relationship between the Doppler frequencies fd1 and fd2 and time. In FIG. 5, the solid line shows the change of the Doppler frequency fd1 with respect to time, and the dotted line shows the change of the Doppler frequency fd2 with respect to time.

  Therefore, the Doppler frequency difference Δf between the two mobile bodies 1a and 1b is obtained by the following equation (7).

図６は、上記のドップラー周波数差Δｆと時間との関係の一例を示す。また、図２（Ｃ）は、上記のドップラー周波数差Δｆと移動体１ａ及び１ｂ間の距離の中心位置との間の関係の一例を示す。図２（Ｃ）及び図６に示すように、最大の周波数差Δｆmaxが得られた時間における２台の移動体１ａ及び１ｂ間の距離の中心位置が、電波発射源７のＸ軸方向の位置Ｘ０である。

FIG. 6 shows an example of the relationship between the Doppler frequency difference Δf and time. FIG. 2C shows an example of the relationship between the Doppler frequency difference Δf and the center position of the distance between the moving bodies 1a and 1b. As shown in FIG. 2C and FIG. 6, the center position of the distance between the two mobile bodies 1a and 1b at the time when the maximum frequency difference Δfmax is obtained is the position of the radio wave emission source 7 in the X-axis direction. X0.

  The frequency difference between the two received signals detected by the frequency difference detection unit 3 shown in FIG. 1 represents Δf in the equation (7). Here, in the equation (7), the wavelength λ is determined by the reception frequency, the distance d between the moving bodies 1a and 1b is known, the speed v and the position information vt are the speed information and position from the position information processing unit 4. Since it is obtained from the information, only the position coordinates X0 and Y0 of the radio wave emission source 7 are unknown values.

  The maximum frequency difference detection unit 5 in FIG. 1 detects the maximum value Δfmax of the frequency difference Δf detected by the frequency difference detection unit 3. 1 obtains position information of the moving bodies 1a and 1b when the maximum frequency difference Δfmax is obtained from the position information processing section 4, and the moving body 1a and The center position of the distance between 1b, that is, the position X0 of the radio wave emission source 7 in the X-axis direction is calculated.

  Further, the frequency difference Δf represented by the equation (7) becomes the maximum value Δfmax at a point where X0 = vt in the equation (7). Therefore, Δfmax is expressed by the following equation by substituting X0 = vt into equation (7).

よって、電波発射源７のｙ軸方向の位置Ｙ０は、（８）式をＹ０について整理することにより次式で算出される。

Therefore, the position Y0 of the radio wave emission source 7 in the y-axis direction is calculated by the following formula by arranging the formula (8) for Y0.

図７は、周波数差の最大値Δｆmaxと電波発射源７のｙ軸方向の位置との関係の一例を示す。また、図２（Ｂ）は、上記の周波数差Δｆと電波発射源７のｙ軸方向との関係の一例を示す。電波発射源７のｙ軸方向の位置に応じて、（９）式に示すように周波数差の最大値Δｆmaxは変化し、また、周波数差Δｆも図２（Ｂ）に示すように変化するが、電波発射源７のｙ軸方向の位置Ｙ０は、（９）式により決定される。

FIG. 7 shows an example of the relationship between the maximum frequency difference Δfmax and the position of the radio wave emission source 7 in the y-axis direction. FIG. 2B shows an example of the relationship between the frequency difference Δf and the y-axis direction of the radio wave emission source 7. Depending on the position of the radio wave emission source 7 in the y-axis direction, the maximum value Δfmax of the frequency difference changes as shown in the equation (9), and the frequency difference Δf also changes as shown in FIG. The position Y0 of the radio wave emission source 7 in the y-axis direction is determined by equation (9).

  Thus, according to the present embodiment, the maximum value of the frequency difference between the two received signals respectively received by the two mobile bodies 1a and 1b moving at the same speed in the same direction at a constant interval (distance). And the position of the radio wave emission source 7 can be measured based on the speed and position information of the mobile bodies 1a and 1b. For the measurement of the position of the radio wave emission source, the “arrival time difference” or “ "Radio arrival direction" is not required.

  Therefore, according to the present embodiment, the position of the radio wave emission source can be measured even if the received signal is a narrowband signal or only an unmodulated carrier wave. Moreover, according to this embodiment, since many antennas are unnecessary, the circuit scale and dimension from the base station communication part 2 to the emission source position calculating part 6 are realizable. In addition, the calculation is very simple and high-speed processing is possible.

  In the above embodiment, the moving bodies 1a and 1b move while maintaining the same altitude. However, when the altitude changes at a constant inclination, the time change amount in the Y direction must also be taken into consideration. However, the present invention can be applied to a slightly complicated expression as compared with movement at the same altitude.

  Further, the present invention is not limited to the above-described embodiment. For example, the moving body used in the present invention is not limited to an aircraft, and may be an automobile, an artificial satellite, or the like.

DESCRIPTION OF SYMBOLS 1a, 1b Mobile body 2 Base station communication part 3 Frequency difference detection part 4 Position information processing part 5 Maximum frequency difference detection part 6 Emergence source position calculation part 7 Radio wave emission source 10 Position measuring device

Claims (8)

Two mobile objects moving in the same direction at the same speed at a constant distance receive radio waves from radio wave emission sources, transmit the received signals, and location information of their current position Each of which is transmitted and the position information is transmitted,
Based on the received signal and the position information transmitted by the two mobile units, the maximum value of the frequency difference between the two received signals respectively received by the two mobile units is detected, and the two positions are detected. A detection and calculation step for calculating position and speed information of the two moving bodies at the time of signal reception from a time change of information;
A position measuring method comprising: calculating a position of the radio wave emission source based on the maximum value of the frequency difference and the position and velocity information. Two mobile objects moving in the same direction at the same speed at a constant distance receive radio waves from radio wave emission sources, transmit the received signals, and location information of their current position Each of which is transmitted and the position information is transmitted,
A reception step of receiving the received signal and the position information transmitted by the two mobile units;
A frequency difference detecting step of detecting a frequency difference between the two received signals transmitted by the two mobile units received in the receiving step;
A maximum value detecting step for detecting a maximum value of the frequency difference detected in the frequency difference detecting step;
A position and velocity information calculating step for calculating position and velocity information of the two moving bodies at the time of signal reception from time changes of the two pieces of position information respectively transmitted by the two moving bodies received in the receiving step; ,
A calculation step of calculating the position of the radio wave emission source based on the maximum value of the frequency difference detected in the maximum value detection step and the position and velocity information calculated in the position and velocity information calculation step. A position measuring method characterized by the above. The calculation step includes:
Based on the position and velocity information, the maximum value of the frequency difference is obtained when the center position of the distance between the two mobile objects is located at the x-axis direction of the radio wave emission source. A first step of calculating the position of
Based on the mathematical formula obtained by substituting the calculation result of the position in the x-axis direction obtained in the first step into the mathematical formula of the maximum value of the frequency difference, the position of the radio wave emission source in the y-axis direction is determined. The position measuring method according to claim 1, further comprising: a second step of calculating. The distance between the two moving bodies is d, the velocity is v, the position information when the maximum value of the frequency difference is obtained is vt, the wavelength of the carrier wave of the received signal is λ, and the frequency difference is When the maximum value is Δfmax,
In the first step, the position information vt is calculated as the position of the radio wave emission source in the x-axis direction.

The position measurement method according to claim 3, wherein the position of the radio wave emission source in the y-axis direction is calculated. It has a function to receive each radio wave and transmit the received signal, and a function to acquire and transmit position information of its current position, and move in the same direction at the same speed with a fixed distance from each other First and second moving bodies to perform,
Communication means for receiving the received signal and the position information transmitted from the first and second moving bodies, respectively;
Based on the received signals received by the first and second mobile units from the communication means and the acquired location information, the frequencies of the two received signals received by the first and second mobile units, respectively. Detecting and calculating means for detecting the maximum value of the difference and calculating the position and velocity information of the first and second moving bodies at the time of signal reception from the time change of the two pieces of position information;
A position measuring device comprising: a calculating means for calculating the position of the radio wave emission source based on the maximum value of the frequency difference and the position and velocity information. It has a function to receive each radio wave and transmit the received signal, and a function to acquire and transmit position information of its current position, and move in the same direction at the same speed with a fixed distance from each other First and second moving bodies to perform,
Communication means for receiving the received signal and the position information transmitted from the first and second moving bodies, respectively;
A frequency difference detecting means for detecting a frequency difference between the two received signals from the first and second moving bodies received by the communication means;
Maximum frequency difference detecting means for detecting a maximum value of the frequency difference detected by the frequency difference detecting means;
A position for calculating the position and speed information of the first and second moving bodies at the time of signal reception from the time change of the two pieces of position information from the first and second moving bodies received by the communication means; and Speed information calculating means;
A computing means for computing the position of the radio wave emission source based on the maximum value of the frequency difference detected by the maximum frequency difference detecting means and the position and speed information calculated by the position and speed information calculating means; A position measuring device comprising: The computing means is
Based on the position and velocity information, the maximum value of the frequency difference is obtained when the center position of the distance between the first and second moving bodies is obtained. first position calculating means for calculating a position in the x-axis direction;
Based on the mathematical expression obtained by substituting the calculation result of the position in the x-axis direction obtained by the first position calculation means into the mathematical expression of the maximum value of the frequency difference, the y-axis direction of the radio wave emission source The position measuring device according to claim 5, further comprising second position calculating means for calculating a position. The distance between the first and second moving bodies is d, the velocity is v, the position information when the maximum value of the frequency difference is obtained is vt, the wavelength of the carrier wave of the received signal is λ, When the maximum value of the frequency difference is Δfmax,
The first position calculation means calculates the position information vt as the position of the radio wave emission source in the x-axis direction, and the second position calculation means has the following formula:

The position measuring device according to claim 7, wherein the position of the radio wave emission source in the y-axis direction is calculated.

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