JP5599371B2 - Positioning device - Google Patents

Description

  The present invention relates to a positioning device that measures the position of a radio wave source such as a ground transmitting station that transmits illegal radio waves.

  For example, in the following Non-Patent Document 1, information on arrival time difference (TDOA: Time Difference of Arrival), which is a difference between arrival times of radio waves transmitted from radio sources having unknown positions, and two satellites, A technique for positioning the position of a radio wave source using information on the Doppler frequency difference (FDOA: Frequency Difference of Arrivation) of radio waves arriving at two satellites is disclosed.

FIG. 5 is a conceptual diagram showing the positioning process of the position of the radio wave source disclosed in Non-Patent Document 1.
In the example of FIG. 5, since a radio wave is transmitted from a radio wave source whose position is unknown and the radio wave has a spatial width such as a side lobe in addition to the main lobe, two satellites # 1 , # 2 is received.
By performing two-dimensional correlation processing on the received signals related to the radio waves received by the two satellites # 1 and # 2, the radio wave arrival time difference TDOA and the Doppler frequency difference FDOA are calculated.
Then, the position of the radio wave source is determined from the radio wave arrival time difference TDOA and the Doppler frequency difference FDOA.

ただし、ｐ₀は電波源の３次元位置ベクトル、ｐ_s1は衛星＃１の３次元位置ベクトル、ｐ_s2は衛星＃２の３次元位置ベクトルである。 FIG. 6 is a block diagram showing a conventional positioning device.
The correlation value calculation unit 51 calculates a radio wave arrival time difference TDOA and a Doppler frequency difference FDOA by performing a two-dimensional correlation process on the received signals related to the radio waves received by the two satellites # 1 and # 2.
Specifically, the radio wave arrival time difference TDOA and the Doppler frequency difference FDOA are calculated as follows.
Actually, before calculating the arrival time difference TDOA and the Doppler frequency difference FDOA, each variable is defined as follows.
Times of arrival (TOA: Time of Arrival) τ ₁ and τ ₂ , which are times when radio waves transmitted from radio sources with unknown positions arrive at the two satellites # 1 and # 2, are expressed by the following equation (1): , (2).

Here, p ₀ is the three-dimensional position vector of the radio wave source, p _s1 is the three-dimensional position vector of satellite # 1, and p _s2 is the three-dimensional position vector of satellite # 2.

ただし、ｖ_s1は衛星＃１の３次元速度ベクトル、ｖ_s2は衛星＃２の３次元速度ベクトルである。
また、λ＝ｃ／ｆ_cは波長であり、ｆ_cは受信信号のキャリア周波数である。 Further, Doppler frequencies FOA (Frequency Of Arrivals) f _d1 and f _d2 due to the influence of the speeds of the satellites # 1 and # 2 are expressed by the following equations (3) and (4).

Here, v _s1 is the three-dimensional velocity vector of satellite # 1, and v _s2 is the three-dimensional velocity vector of satellite # 2.
Also, λ = _c / f c is the wavelength, the f _c is the carrier frequency of the received signal.

ここでは、位置が未知である電波源は、地表面にあると仮定するので、

である。ただし、Ｒｅは地球の半径である。 Thereby, the arrival time difference TDOA is represented by the following equation (5), and the Doppler frequency difference FDOA is represented by the following equation (6).

Here, it is assumed that the radio wave source whose position is unknown is on the ground surface.

It is. Where Re is the radius of the earth.

If the values of the arrival time difference TDOA and the Doppler frequency difference FDOA are obtained, the positioning unit 53, which will be described later, converts the simultaneous equations of equations (5), (6), and (7) into the three-dimensional position vector p ₀ of the radio wave source. Can be used to determine the three-dimensional position of the radio wave source.
At this time, since the three-dimensional position vectors p _s1 and p _s2 and the three-dimensional velocity vectors v _s1 and v _s2 are available as satellite orbit information, the only unknown variable is the three-dimensional position vector p ₀ of the radio wave source. .
Since the dimension of p ₀ is three, the number of unknowns is 3, and the number of equations is 3, so that simultaneous equations can be solved.

ただし、ａ（ｔ）は帯域を有する成分であり、ω_c＝２πｆ_cである。 First, the correlation value calculation unit 51 defines a transmission signal s (t) related to a radio wave transmitted from a radio wave source as shown in the following equation (8).

However, a (t) is a component having a bandwidth, which is ω _c = 2πf _c.

式（９），（１０）において、τ₁，τ₂は電波の到来時間ＴＯＡであり、式（９），（１０）は、ドップラー周波数ＦＯＡであるｆ_d1，ｆ_d2を用いると、下記の式（１１），（１２）で表される。

ただし、ω_d＝２πｆ_dである。 In this case, the received signals s ₁ (t) and s ₂ (t) of the _two satellites # 1 and # 2 are expressed by the following equations (9) and (10).

In equations (9) and (10), τ ₁ and τ ₂ are the arrival times TOA of the radio waves, and equations (9) and (10) are expressed as follows when f _d1 and f _d2 that are Doppler frequency FOA are used. It is expressed by equations (11) and (12).

However, ω _d = 2πf _d .

この２次元相関は、下記の式（１４）において、τがＴＤＯＡ、ｆがＦＤＯＡであるときにピークを有し、その他の場合は、低い値をとる。
よって、相関ピークにおけるτがＴＤＯＡ、ｆがＦＤＯＡとなる。

The correlation value calculation unit 51 calculates the arrival time difference TDOA and the Doppler frequency difference FDOA from the received signals s ₁ (t) and s ₂ (t) represented by the expressions (11) and (12). The two-dimensional correlation represented by (13) is calculated.

This two-dimensional correlation has a peak when τ is TDOA and f is FDOA in the following formula (14), and takes a low value in other cases.
Therefore, τ at the correlation peak is TDOA, and f is FDOA.

ただし、Δｔ＝１／ｆ_sは時間方向のサンプル周期、Δｆ＝１／Ｔは周波数方向のサンプル周期、Ｋはサンプル総数である。 In practice, the following discrete correlation calculation is used with the signal discretized by the A / D converter. The discretized signal is rewritten by the following equation.

However, Δt = 1 / f _s is the sample period of the time direction, Δf = 1 / T is the sample period of the frequency direction, K is a total number of samples.

式（１７）は、式（１３）と同様に、相関ピークを持つｎ（τ＝Δｔｎ）がＴＤＯＡの値となり、相関ピークを持つｍ（ｆ＝Δｆｍ）がＦＤＯＡの値となる。 At this time, if f _s is the sampling frequency and T is the sample time length, the discretized two-dimensional correlation calculation is expressed by the following equation (17).

In Expression (17), similarly to Expression (13), n (τ = Δtn) having a correlation peak is a TDOA value, and m (f = Δfm) having a correlation peak is an FDOA value.

When the correlation value calculation unit 51 calculates the arrival time difference TDOA and the Doppler frequency difference FDOA, the peak detection unit 52 detects the arrival time difference TDOA and the Doppler frequency difference FDOA that maximize the correlation value.
When the peak detection unit 52 detects the arrival time difference TDOA and the Doppler frequency difference FDOA with the maximum correlation value, the positioning unit 53 substitutes the arrival time difference TDOA and the Doppler frequency difference FDOA into the equations (5) and (6). Then, the three-dimensional position of the radio wave source is determined by solving the simultaneous equations of equations (5), (6), and (7) for the three-dimensional position vector p ₀ of the radio wave source.

D. P. Haworth, et.al, “Interference Localization For Eutelsat Satellites -The First European Transmitter Location System,” International Journal ff Satellite Communications, Vol. 15, 155-183, 1997

Since the conventional positioning apparatus is configured as described above, it is necessary to calculate the peak of the two-dimensional correlation, but in the correlation calculation, the values of TDOA and FDOA within the observation time are constant, and the peak If only one is assumed and these assumptions do not hold, the following problem occurs.
First, since satellites # 1 and # 2 move at high speed, fluctuations in the values of TDOA and FDOA within the observation time cannot be ignored. When the time variation of TDOA and FDOA within the observation time cannot be ignored (see FIG. 7), the correlation peaks do not accumulate, so the accuracy of TDOA and FDOA deteriorates and the positioning accuracy deteriorates. There was a problem.
When a periodic signal such as a radar pulse signal is received, an ambiguity corresponding to a pulse period PRI (Pulse Repeat Interval) is generated (see FIG. 8). When ambiguity occurs, a plurality of peaks are detected by the correlation calculation, so that a plurality of positioning position candidates are obtained, and there is a problem that the three-dimensional position of the radio wave source cannot be specified.

The present invention has been made to solve the above-described problems, and provides a positioning device that can measure the exact position of a radio wave source without deteriorating positioning accuracy associated with high-speed movement of a satellite. With the goal.
Further, according to the present invention, when a periodic signal such as a radar pulse signal is received, an accurate position of the radio wave source can be measured even if an ambiguity corresponding to the pulse period PRI is generated. The purpose is to obtain a positioning device.

  The positioning apparatus according to the present invention includes a candidate position setting unit that sets a plurality of candidate positions where a radio wave source having an unknown position may exist, and a radio wave at each candidate position set by the candidate position setting unit. A plurality of satellites using the arrival time calculation means for calculating the time when radio waves transmitted from the radio wave source arrive at a plurality of satellites, and the arrival time calculated by the arrival time calculation means. A received signal compensator for compensating the received signal related to the radio wave received by the apparatus, and an inner product value calculating means for calculating an inner product value between a plurality of received signals compensated by the received signal compensator; Among the plurality of candidate positions set by the candidate position setting means, a candidate position where the inner product value calculated by the inner product value calculating means is maximized is specified, and the candidate position is output as a positioning result of the radio wave source. It is obtained by way.

  According to the present invention, candidate position setting means for setting a plurality of candidate positions where a radio wave source having an unknown position may exist, and a radio wave source is provided at each candidate position set by the candidate position setting means. Assuming there is an arrival time calculating means for calculating the time when the radio wave transmitted from the radio wave source arrives at the plurality of satellites, and the arrival time calculated by the arrival time calculating means is received by the plurality of satellites. A reception signal compensation means for compensating the received signal related to the received radio wave, and an inner product value calculation means for calculating an inner product value between a plurality of reception signals compensated by the reception signal compensation means. Among the plurality of candidate positions set by the position setting means, a candidate position where the inner product value calculated by the inner product value calculating means is maximized is specified, and the candidate position is output as a positioning result of the radio wave source. Since it is configured to, without deteriorating the positioning accuracy due to the fast movement of the satellite, there is an effect capable of positioning the exact location of the radio sources.

It is a block diagram which shows the positioning apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows the compensation process of the positioning apparatus by Embodiment 1 of this invention. It is a block diagram which shows the positioning apparatus by Embodiment 3 of this invention. It is a block diagram which shows the positioning apparatus by Embodiment 4 of this invention. It is a conceptual diagram which shows the positioning process of the position of the radio wave source currently disclosed by the nonpatent literature 1. It is a block diagram which shows the conventional positioning apparatus. It is explanatory drawing which shows the time fluctuation of TDOA / FDOA by the high-speed movement of a satellite. It is explanatory drawing which shows generation | occurrence | production of the ambiguity for the part corresponded to pulse period PRI.

Embodiment 1 FIG.
1 is a block diagram showing a positioning apparatus according to Embodiment 1 of the present invention.
In FIG. 1, the candidate position setting unit 1 divides the ground surface (area indicated by the radio wave source position candidate range given from the outside) where a radio wave source may exist into a grid shape, and each divided area is divided into radio wave sources. and it carries out a process of but set to the candidate position p _c that may be present. The candidate position setting unit 1 constitutes candidate position setting means.
The movement compensation amount calculation unit 2 refers to the orbit information of the two satellites # 1 and # 2 (for example, the three-dimensional position vectors p _s1 and p _{s2 of} the satellites # 1 and # 2), and the candidate position setting unit 1 _Assuming that a radio wave source exists at each set candidate position p _c , the time τ _c1 (t), τ _c2 (t) at which the radio wave transmitted from the radio wave source arrives at satellites # 1 and # 2 is _calculated. Perform the calculation process. The movement compensation amount calculation unit 2 constitutes arrival time calculation means.

The received signal movement compensation unit 3 uses the arrival times τ _c1 (t) and τ _c2 (t) calculated by the movement compensation amount calculation unit 2 to receive signals related to the radio waves received by the satellite # 1 and the satellite # 2. A process of compensating for s ₁ (t) and s ₂ (t) is performed. The reception signal movement compensation unit 3 constitutes reception signal compensation means.
The inner product value calculation unit 4 performs a process of calculating the inner product value cor (p _c ) between the reception signals c ₁ (t) and c ₂ (t) after compensation by the reception signal movement compensation unit 3. The inner product value calculation unit 4 constitutes an inner product value calculation means.

All candidate position processing end determining unit 5 for all of the candidate position p _c set by the candidate position setting unit 1, the processing of the movement compensation quantity calculation section 2, the received signal motion compensation unit 3 and the inner product value calculating unit 4 is completed and it is judged whether or not the that, until the processing for all the candidate positions p _c ends, movement compensation quantity calculation section 2, thereby repeatedly executes the processing of the received signal motion compensation unit 3 and the inner product value calculating unit 4.
Positioning result output unit 6 among the plurality of candidate positions p _c set by the candidate position setting unit 1, the candidate position p _c inner product inner product values calculated by the calculating unit 4 cor where (p _c) is maximized identified, and carries out a process of outputting the candidate position p _c as a positioning result of the radio wave sources. The positioning result output unit 6 constitutes positioning result output means.

In the example of FIG. 1, the candidate position setting unit 1, the movement compensation amount calculation unit 2, the received signal movement compensation unit 3, the inner product value calculation unit 4, the all candidate position processing end determination unit 5, and the positioning results that are components of the positioning device Although each of the output units 6 is assumed to be configured with dedicated hardware (for example, a semiconductor integrated circuit on which a CPU is mounted or a one-chip microcomputer), the positioning device is configured with a computer. It may be.
When the positioning device is configured by a computer, the candidate position setting unit 1, the movement compensation amount calculation unit 2, the received signal movement compensation unit 3, the inner product value calculation unit 4, the all candidate position processing end determination unit 5, and the positioning result output unit 6 may be stored in a memory of a computer, and the CPU of the computer may execute the program stored in the memory.

Next, the operation will be described.
As an overview of the positioning device of FIG. 1, for each of a plurality of candidate positions p _c which may radio sources is present, originating from the radio wave source that may be present in the candidate position p _c Times τ _c1 (t) and τ _c2 (t) when radio waves arrive at satellites # 1 and # 2 are calculated, and using the arrival times τ _c1 (t) and τ _c2 (t), satellites # 1 and # 2 Compensate the received signals s ₁ (t) and s ₂ (t) of # ₂ (compensate the influence of the received signals s ₁ (t) and s ₂ (t) associated with the high-speed movement of satellite # 1 and satellite # 2. ). The received signal c ₁ after compensation (t), is calculated the c ₂ (t) the inner product values between cor (p _c), the higher the inner product value, because it means a high similarity, all among the candidate position p _c, selects a candidate position p _c where the inner product value is the highest as a result the final positioning.
As a result, the positioning accuracy can be improved. Further, in the case of a periodic signal such as a radar pulse, even if a compensation value based on the ambiguity position is used, the correlation peak does not increase, and as a result, ambiguity can be eliminated.

ただし、ａ（ｔ）は帯域を有する成分であり、ω_c＝２πｆ_cである。 Hereinafter, the processing content of the positioning apparatus of FIG. 1 is demonstrated concretely.
First, a transmission signal s (t) related to a radio wave transmitted from an unknown radio wave source is defined as in the following equation (18). Expression (18) is the same as Expression (8) described in the background art.

However, a (t) is a component having a bandwidth, which is ω _c = 2πf _c.

ここで、式（１９），（２０）と背景技術に記載している式（８），（９）との違いは、電波の到来時間ＴＯＡであるτ₁（ｔ），τ₂（ｔ）が時間の関数になっている点である。 In this case, the received signals s ₁ (t) and s ₂ (t) of the _two satellites # 1 and # 2 are expressed by the following equations (19) and (20).

Here, the difference between the formulas (19) and (20) and the formulas (8) and (9) described in the background art is that τ ₁ (t) and τ ₂ (t) which are radio wave arrival times TOA. Is a function of time.

In this case, τ ₁ (t) and τ ₂ (t) at time t are expressed by the following equations (21) and (22).

Hereinafter, it is assumed that the received signals s ₁ (t) and s ₂ (t) of the two satellites # 1 and # 2 are down-converted by ω _{h in} the processing on the receiving side.

When the arrival time difference TDOA and the Doppler frequency difference FDOA greatly vary within the observation time due to the movement of the satellites # 1 and # 2, the reception is performed according to Expression (13) or Expression (17) described in the background art. Even if the correlation calculation of the signals s ₁ (t) and s ₂ (t) is performed, the correlation does not build up, so that a sharp correlation peak cannot be obtained.
Therefore, in the first embodiment, a method of calculating the inner product value after compensating the movement of the received signals s ₁ (t) and s ₂ (t) is adopted.
That is, assuming the candidate of a determined position and p _c, using the candidate position p _c, satellite # 1, # 2 of the received signal _{s 1 (t), s 2} (t) is compensated such that the same becomes The inner product value between the compensated received signals c ₁ (t) and c ₂ (t) is calculated.
If this inner product value is high, it means that the similarity between the received signals is high. Therefore, if the candidate position _pc is correct, it means that compensation has been correctly performed, and a high inner product value can be obtained.

First, the candidate position setting unit 1 divides the ground surface where the radio wave source may exist (the area indicated by the radio wave source position candidate range given from the outside) into a grid shape, and each radio wave source is divided into each divided area. set to which may be present candidate position p _c.
Then, the output from a plurality of candidate positions p _c, yet any candidate position p _c is not selected Select one the movement compensation quantity calculation section 2.

Movement compensation amount calculation unit 2 receives the one candidate position p _c from the candidate position setting unit 1, assuming that the radio wave source is present in the candidate position p _c, satellite # 1, # 2 of orbit information using (satellite # 1, # 3-dimensional positions of the two vectors p _s1, p _s2), the candidate position p radio wave transmitted from the radio wave source is present in _c satellite # 1, the time arriving at # 2 τ _c1 (t) and τ _c2 (t) are calculated.

When the movement compensation amount calculation unit 2 calculates the arrival times τ _c1 (t) and τ _c2 (t), the received signal movement compensation unit 3 uses the arrival times τ _c1 (t) and τ _c2 (t), The received signals s ₁ (t) and s ₂ (t) related to the radio waves received by the satellite # 1 and the satellite # 2 are compensated.
Here, it is assumed that the carrier frequency ω _c is unknown.
The down-conversion frequency ω _h is known, but since ω _h ≠ ω _c , the carrier component remains.
Therefore, the received signal movement compensator 3 compensates the received signals s ₁ (t) and s ₂ (t) as in the following equations (27) and (28), and a compensated signal that is a received signal after compensation: c ₁ (t) and c ₂ (t) are output.

When the inner product value calculation unit 4 receives the compensation signals c ₁ (t) and c ₂ (t) from the received signal movement compensation unit 3, the similarity between the compensation signal c ₁ (t) and the compensation signal c ₂ (t) , The inner product value cor (p _c ) between the compensation signals c ₁ (t) and c ₂ (t) is calculated as shown in the following equation (29).

この場合、式（２９）の内積値は最大値をとる。

At this time, if the candidate position p _c is correct, τ _c1 (t) = τ ₁ (t), τ _c2 (t) = τ ₂ (t), and the equation (27) is expressed by the following equation (30): It is expressed as Similarly, Expression (28) is expressed as Expression (31) below.

In this case, the inner product value of Expression (29) takes the maximum value.

All candidate position processing end determining unit 5, for all the candidate positions p _c set by the candidate position setting unit 1, the processing of the movement compensation quantity calculation section 2, the received signal motion compensation unit 3 and the inner product value calculating unit 4 ends determines whether (calculation of the inner product value cor (p _c) is terminated) are, until the processing for all the candidate positions p _c ends, movement compensation quantity calculation section 2, the received signal motion compensation unit 3 and The process of the inner product value calculation unit 4 is repeatedly performed.
Note that when the processes of the movement compensation amount calculation unit 2, the received signal movement compensation unit 3, and the inner product value calculation unit 4 are repeatedly performed under the instruction of the all candidate position processing end determination unit 5, the candidate position setting unit 1 is still selected. and it outputs an arbitrary candidate position p _c which is not one selected and the movement compensation quantity calculation section 2.

Positioning result output unit 6, for all the candidate positions p _c set by the candidate position setting unit 1, the calculation of the inner product value cor (p _c) is completed, all the candidates set by the candidate position setting unit 1 among the positions p _c, the inner product value inner product value calculated by the calculating unit 4 cor (p _c) is to identify the candidate position p _c becomes maximum, and outputs the candidate location p _c as a positioning result of the radio wave sources.
Since the compensation value for the ambiguity position is different from the true compensation value, a correlation peak does not appear at the ambiguity position, and a correlation peak appears only at the correct position.
Therefore, only the correct position can be output as a positioning result by eliminating the ambiguity position.

また、信号が正弦波である場合、式（３０）は下記の式（３５）のように表され、式（３１）は下記の式（３６）のように表される。

また、ω_h＝ω_cであり、かつ、信号が正弦波である場合、式（３０）は下記の式（３７）のように表され、式（３１）は下記の式（３８）のように表される。

Up to this point, an example in which ω _h ≠ ω _c has been described, but when ω _h = ω _c , if the candidate position p _c is the correct answer, τ _c1 (t) = τ ₁ (t), τ _c2 (T) = τ ₂ (t), and the expression (30) is expressed as the following expression (33), and the expression (31) is expressed as the following expression (34).

When the signal is a sine wave, the expression (30) is expressed as the following expression (35), and the expression (31) is expressed as the following expression (36).

Further, when ω _h = ω _c and the signal is a sine wave, the expression (30) is expressed as the following expression (37), and the expression (31) is expressed as the following expression (38). It is expressed in

実際の処理は、以上を置き換えて行えばよく、式（３２）に示す内積値の最大値は、下記の式（４０）となる。

As a matter common to the first embodiment and later-described embodiments, the signal transmitted from the radio wave source is described as a continuous signal. However, in actual signal processing, the signal is sampled by an A / D converter. Since discrete signals are handled, each expression is replaced as follows.
(1) The received signal is s ₁ (k) = s ₁ (t) | _{t = Δtk} , s ₂ (k) = s ₂ (t) | _{t = Δtk}
Thus, it is obtained discretely with the sample period Δt.
(2) When generating the compensation signals c ₁ (k) and c ₂ (k), since information between samples cannot be obtained with discrete signals, for example, some interpolation processing such as spline interpolation is used.
(3) Expression (29) for calculating the inner product value is replaced with the following expression (39).

The actual processing may be performed by replacing the above, and the maximum value of the inner product value shown in the equation (32) is expressed by the following equation (40).

However, it is necessary to pay attention to the following points.
(1) In the equations (27) and (28), as shown in FIG.
The compensation signals c ₁ (t) and c ₂ (t) are compensated so that TOA and FOA become zero.
(2) In equations (27) and (28), the compensation signals c ₁ (t) and c ₂ (t) are calculated from the received signals s ₁ (t) and s ₂ (t). , Arrival time τ ₁ (t)
, Τ ₂ (t) (Δτ ₁₂ (t) = τ ₁ (t) −τ ₂ (t))
If it is necessary to reduce the time shift amount in the interpolation process, the bias component can be removed and the shift amount set (see FIG. 2B).
That is, the actual shift amount may be τ ₁ (t) −b, τ ₂ (t) −b.
(3) In equations (27) and (28), the compensation signals c ₁ (t) and c ₂ (t) are calculated from the received signals s ₁ (t) and s ₂ (t). , Arrival time τ ₁ (t)
, Τ ₂ (t) difference (Δτ ₁₂ (t) = τ ₁ (t) −τ ₂ (t)) only, Δτ ₁₂ (t) need only be shifted by one (FIG. 2 (c)). See).
For example, only the signal having a higher S / N may be subjected to the interpolation process.

As apparent from the above, according to the first embodiment, the ground surface where the radio wave source may exist (the area indicated by the radio wave source position candidate range given from the outside) is divided into a grid shape, a candidate position setting unit 1 for setting the candidate position p _c which may each divided area radio sources are present, radio source is present in each of the candidate positions p _c set by the candidate position setting unit 1 A movement compensation amount calculation unit 2 for calculating times τ _c1 (t) and τ _c2 (t) when radio waves transmitted from the radio wave source arrive at satellites # 1 and # 2, and a movement compensation amount calculation unit Using the arrival times τ ₁ (t) and τ ₂ (t) calculated according to 2, the received signals s ₁ (t) and s ₂ (t) related to the radio waves received by the satellites # 1 and # 2 are compensated. Received signal movement compensator 3 and a compensation signal that is a received signal after compensation by received signal movement compensator 3. c ₁ (t), the inner product value calculating unit 4 is provided for calculating c ₂ (t) is the inner product values between cor (p _c), the positioning result output unit 6, a plurality of which are set by the candidate position setting unit 1 among the candidate positions p _c, the inner product value calculating unit 4 inner product values calculated by cor (p _c) is to identify the candidate position p _c becomes maximum, and outputs the candidate location p _c as a positioning result of the radio wave source Since it comprised in this way, there exists an effect which can position the exact position of a radio wave source, without causing the deterioration of the positioning accuracy accompanying satellite # 1 and # 2 moving at high speed.

In the first embodiment, two satellites # 1 and # 2 receive radio waves transmitted from radio sources. However, three or more satellites receive radio waves transmitted from radio sources. You may make it do.
For example, when three satellites # 1, # 2, and # 3 receive radio waves transmitted from radio sources, the time τ ₁ (t), τ ₂ when the radio waves arrive at satellites # 1, # 2, and # 3 (T), τ ₃ (t) are calculated, and the received signals of the satellites # 1, # 2, # 3 are used by using the arrival times τ ₁ (t), τ ₂ (t), τ ₃ (t). _{s 1 (t), s 2} (t), to compensate s ₃ a (t), and the compensation signal _{c 1 (t), c 2} (t) inner product value cor ₁ (p _c) between the compensation signal c ₂ (t), calculates c ₃ (t) and the inner product value cor ₂ (p _c) between the compensation signal c ₃ (t), c ₁ (t) inner product between cor ₃ and (p _c).
The identified among a plurality of candidate positions p _c, for example, the sum of the inner product value _{(cor 1 (p c) +} cor 2 (p c) + cor 3 (p c)) is maximized candidate position p _c, as a candidate position p _c is output as the positioning result of the radio wave sources.

Embodiment 2. FIG.
The configuration of the positioning device according to the second embodiment is the same as that of the positioning device according to the first embodiment, but the method of movement compensation is different.
Here, as the carrier frequency f _c is known and the received signal movement compensation section 3, by using the carrier frequency f _c, is described a method of performing motion compensation.

Hereinafter, it is assumed that the received signals s ₁ (t) and s ₂ (t) of the satellites # 1 and # 2 are down-converted by ω _{h in} a certain frequency band.

式（４３），（４４）では、キャリア周波数ω_cが既知であるとして、キャリア成分を除去するためのｅ^-j(ωc-ωd)t項による乗算を加えている。 When the received signals s ₁ (t) and s ₂ (t) of the satellites # 1 and # 2 are compensated to be the same signal, the compensation signals c ₁ (t) and c ₂ (t) are expressed by the following equation (43) ), (44).

In the equations (43) and (44), assuming that the carrier frequency ω _c is known, multiplication by an e ^{−j (ωc−ωd) t} term for removing the carrier component is added.

この場合、内積値ｃｏｒ（ｐ_c）は、下記の式（４７）となり、最大値をとる。

In the equations (43) and (44), when the compensation term is correct, p _c = p ₀ , so the equation (43) becomes the following equation (45), and the equation (44) becomes the following equation (46). Become.

In this case, the inner product value cor (p _c), the following equation (47), and a maximum value.

Conversely, if the compensation term is incorrect, equation (29) takes a low value. Utilizing this property, the candidate positions p _c of the radio sources, equation (43) and by calculating the equation (44) to evaluate the inner product value cor (p _c), to the inner product value cor (p _c) maximum the become candidate positions p _c and outputs as a located position.
When the signal is a non-modulated continuous wave (CW), the equations (45) and (46) become the following equations (48) and (49).

Embodiment 3 FIG.
3 is a block diagram showing a positioning apparatus according to Embodiment 3 of the present invention. In the figure, the same reference numerals as those in FIG.
The correlation value calculation unit 11 performs a process of calculating a two-dimensional correlation value ccf (τ, f) between the reception signals c ₁ (t) and c ₂ (t) after compensation by the reception signal movement compensation unit 3. The correlation value calculation unit 11 constitutes a two-dimensional correlation value calculation unit.
The peak detection unit 12 performs a process of detecting the arrival time difference TDOA and the Doppler frequency difference FDOA in which the two-dimensional correlation value ccf (τ, f) calculated by the correlation value calculation unit 11 is maximum.

All candidate position processing end determining unit 13 for all candidate positions p _c set by the candidate position setting unit 1, the movement compensation quantity calculation section 2, the received signal movement compensation section 3, the correlation value calculation section 11 and the peak detector 12 determines whether processing for has been completed, until the processing for all the candidate positions p _c ends, movement compensation quantity calculation section 2, the received signal movement compensation section 3, the correlation value calculation section 11 and the peak detector 12 Repeat the process.
Positioning result output unit 14 among a plurality of candidate positions p _c set by the candidate position setting unit 1, identifies the detected arrival time difference TDOA and Doppler frequency differences FDOA highest candidate positions p _c by the peak detector 12 and, performing the process of outputting the candidate position p _c as a positioning result of the radio wave sources. The positioning result output unit 14 constitutes positioning result output means.

In the example of FIG. 3, the candidate position setting unit 1, the movement compensation amount calculation unit 2, the received signal movement compensation unit 3, the correlation value calculation unit 11, the peak detection unit 12, and all candidate position processing end determinations that are components of the positioning device. It is assumed that each of the unit 13 and the positioning result output unit 14 is configured by dedicated hardware (for example, a semiconductor integrated circuit on which a CPU is mounted, or a one-chip microcomputer). May be configured by a computer.
When the positioning device is configured by a computer, the candidate position setting unit 1, the movement compensation amount calculation unit 2, the received signal movement compensation unit 3, the correlation value calculation unit 11, the peak detection unit 12, and the all candidate position processing end determination unit 13 The program describing the processing contents of the positioning result output unit 14 may be stored in the memory of the computer, and the CPU of the computer may execute the program stored in the memory.

Next, the operation will be described.
As in the first embodiment, the candidate position setting unit 1 divides the ground surface where the radio wave source may exist (the area indicated by the radio wave source position candidate range given from the outside) into a grid shape, set the candidate position p _c which may each divided area radio sources are present.
Then, the output from a plurality of candidate positions p _c, yet any candidate position p _c is not selected Select one the movement compensation quantity calculation section 2.

Movement compensation amount calculation unit 2 receives the one candidate position p _c from the candidate position setting unit 1, as in the first embodiment, assuming that the radio source to the candidate position p _c is present, satellite # 1, # 2 of orbit information using the (satellite # 1, # 2 of the three-dimensional position vector p _s1, p _s2), the candidate position p radio wave transmitted from the radio wave source is present in _c satellite Times τ _c1 (t) and τ _c2 (t) arriving at # 1 and # 2 are calculated (see formulas (25) and (26)).

Received signal movement compensator 3, the movement compensation quantity calculation section 2 is arrival time tau _c1 (t), calculating the tau _c2 (t), as in the first embodiment, the arrival time tau _c1 (t), Using τ _c2 (t), the received signals s ₁ (t) and s ₂ (t) related to the radio waves received by the satellite # 1 and the satellite # 2 are compensated, and a compensated signal that is a compensated received signal c ₁ (t) and c ₂ (t) are output (see equations (27) and (28)).

この２次元相関は、下記の式（５１）において、τがＴＤＯＡ、ｆがＦＤＯＡであるときにピークを有し、その他の場合は、低い値をとる。
よって、相関ピークにおけるτがＴＤＯＡ、ｆがＦＤＯＡとなる。

When the correlation value calculation unit 11 receives the compensation signals c ₁ (t) and c ₂ (t) from the reception signal movement compensation unit 3, as shown in the following formula (50), the correlation signal c ₁ (t) , C ₂ (t), a two-dimensional correlation value ccf (τ, f) is calculated.

This two-dimensional correlation has a peak when τ is TDOA and f is FDOA in the following formula (51), and takes a low value in other cases.
Therefore, τ at the correlation peak is TDOA, and f is FDOA.

When the correlation value calculation unit 11 calculates the two-dimensional correlation value ccf (τ, f), the peak detection unit 12 calculates the arrival time difference TDOA and Doppler frequency difference FDOA that maximize the two-dimensional correlation value ccf (τ, f). To detect. That is, τ at the correlation peak is detected as the arrival time difference TDOA, and f at the correlation peak is detected as the Doppler frequency difference FDOA.
In the first embodiment, the compensation signal c ₁ (t), after calculating the c ₂ (t), the compensation signal c ₁ (t), 2-dimensional correlation value between _{c 2 (t) ccf (τ} , f) is calculated and the correlation peak is detected. In this case, since the correlation peak stands at the origin, the detection of the correlation peak is performed by the compensation signal c ₁ (t ), C ₂ (t) is equivalent to calculating the inner product value.

All candidate position processing end determining unit 13, for all the candidate positions p _c set by the candidate position setting unit 1, the movement compensation quantity calculation section 2, the received signal movement compensation section 3, the correlation value calculation section 11 and the peak detector for 12 ends and determines whether or not (detection processing of the correlation peak is complete) and, until the processing for all the candidate positions p _c ends, movement compensation quantity calculation section 2, the received signal movement compensation section 3, The processing of the correlation value calculation unit 11 and the peak detection unit 12 is repeatedly performed.
In the case where the processes of the movement compensation amount calculation unit 2, the received signal movement compensation unit 3, the correlation value calculation unit 11, and the peak detection unit 12 are repeatedly performed under the instruction of the all candidate position processing end determination unit 13, the candidate position setting is performed. any candidate position p _c where part 1 has not yet selected one selects and outputs the movement compensation quantity calculation section 2.

Positioning result output unit 14, for all the candidate positions p _c set by the candidate position setting unit 1, the detection processing of the correlation peak is ended, among all the candidate positions p _c set by the candidate position setting unit 1 in, time difference of arrival is detected TDOA and Doppler frequency difference FDOA is to identify the highest candidate position p _c by the peak detector 12, and outputs the candidate location p _c as a positioning result of the radio wave sources.
Since the compensation value for the ambiguity position is different from the true compensation value, a correlation peak does not appear at the ambiguity position, and a correlation peak appears only at the correct position.
Therefore, only the correct position can be output as a positioning result by eliminating the ambiguity position.

As apparent from the above, according to the third embodiment, the ground surface where the radio wave source may exist (the area indicated by the radio wave source position candidate range given from the outside) is divided into a grid shape, a candidate position setting unit 1 for setting the candidate position p _c which may each divided area radio sources are present, radio source is present in each of the candidate positions p _c set by the candidate position setting unit 1 A movement compensation amount calculation unit 2 for calculating times τ _c1 (t) and τ _c2 (t) when radio waves transmitted from the radio wave source arrive at satellites # 1 and # 2, and a movement compensation amount calculation unit Using the arrival times τ ₁ (t) and τ ₂ (t) calculated according to 2, the received signals s ₁ (t) and s ₂ (t) related to the radio waves received by the satellites # 1 and # 2 are compensated. Received signal movement compensator 3 and a compensation signal that is a received signal after compensation by received signal movement compensator 3. _{c 1 (t), c 2} (t) 2 -dimensional correlation value ccf between (tau, f) the correlation value calculation unit 11 for calculating the two-dimensional correlation value ccf calculated by the correlation value calculation section 11 (tau, f) is provided and a peak detector 12 for detecting the arrival time difference TDOA and Doppler frequency difference FDOA becomes maximum, the positioning result output section 14, among the plurality of candidate positions p _c set by the candidate position setting unit 1 identifies the highest candidate position p _c is the arrival time difference TDOA and Doppler frequency differences FDOA detected by the peak detection unit 12, and then, is output the candidate position p _c as a positioning result of the radio wave sources, satellite # There is an effect that the accurate position of the radio wave source can be measured without degrading the positioning accuracy accompanying the high-speed movement of # 1 and # 2.

In the third embodiment, two satellites # 1 and # 2 receive radio waves transmitted from a radio wave source. However, as in the first embodiment, three or more satellites are used. You may make it receive the electromagnetic wave transmitted from the radio wave source.
For example, when three satellites # 1, # 2, and # 3 receive radio waves transmitted from radio sources, the time τ ₁ (t), τ ₂ when the radio waves arrive at satellites # 1, # 2, and # 3 (T), τ ₃ (t) are calculated, and the received signals of the satellites # 1, # 2, # 3 are used by using the arrival times τ ₁ (t), τ ₂ (t), τ ₃ (t). s ₁ (t), s ₂ (t), s ₃ (t) are compensated, and the two-dimensional correlation value ccf ₁ (τ, f) between the compensation signals c ₁ (t) and c ₂ (t) is maximum. The arrival time difference TDOA ₁ and the Doppler frequency difference FDOA ₁ , and the arrival time difference TDOA ₂ and the Doppler frequency difference at which the two-dimensional correlation value ccf ₂ (τ, f) between the compensation signals c ₂ (t) and c ₃ (t) is maximized. FDOA _2, and the compensation signal _{c 3 (t), c 1} (t) 2 -dimensional correlation value between ccf ₃ (τ, f) the arrival time difference TDOA ₃ and Doppler is maximum To detect the wave number difference FDOA _3.
Then, among the plurality of candidate positions p _c, for example, the sum of the arrival time difference TDOA and Doppler frequency differences _{FDOA (TDOA 1 + TDOA 2 +} TDOA 3, FDOA 1 + FDOA 2 + FDOA 3) is to identify the candidate position p _c of maximum , so as to output the candidate position p _c as a positioning result of the radio wave sources.

Embodiment 4 FIG.
4 is a block diagram showing a positioning apparatus according to Embodiment 4 of the present invention. In the figure, the same reference numerals as those in FIG.
The coarse positioning unit 21 uses the received signals s ₁ (t) and s ₂ (t) related to the radio waves received by the satellites # 1 and # 2 and the orbit information of the satellites # 1 and # 2, and receives the received signal s _1. By calculating the two-dimensional correlation value between (t) and s ₂ (t) and detecting the peak of the two-dimensional correlation value, rough positioning of the position where the radio wave source exists is performed. The coarse positioning unit 21 constitutes a coarse positioning means.

The radio wave source position candidate range setting unit 22 sets the range around the position roughly measured by the coarse positioning unit 21 to the radio wave source position candidate range (the ground surface where the radio wave source may exist). A process of outputting the source position candidate range to the candidate position setting unit 1 is performed.
The candidate position setting unit 1 and the radio wave source position candidate range setting unit 22 constitute candidate position setting means.

  4 shows an example in which the coarse positioning unit 21 and the radio source position candidate range setting unit 22 are applied to the positioning apparatus of FIG. 1, the rough positioning unit 21 and the radio source position candidate range setting unit 22 are illustrated. 3 positioning devices may be applied.

Next, the operation will be described.
The coarse positioning unit 21 uses the received signals s ₁ (t) and s ₂ (t) related to the radio waves received by the satellites # 1 and # 2 and the orbit information of the satellites # 1 and # 2, and receives the received signal s. A two-dimensional correlation value between ₁ (t) and s ₂ (t) is calculated. That is, the two-dimensional correlation value ccf (τ, f) represented by Expression (13) described in the background art is calculated.
After calculating the two-dimensional correlation value ccf (τ, f), the coarse positioning unit 21 detects the peak of the two-dimensional correlation value ccf (τ, f), and the two-dimensional correlation value ccf (τ, f) is the maximum. The arrival time difference TDOA and the Doppler frequency difference FDOA are detected.

When the coarse positioning unit 21 detects the arrival time difference TDOA and the Doppler frequency difference FDOA, the coarse positioning unit 21 substitutes the arrival time difference TDOA and the Doppler frequency difference FDOA into Equations (5) and (6) described in the background art, The three-dimensional position of the radio wave source is roughly determined by solving the simultaneous equations 5), (6), and (7) with respect to the three-dimensional position vector p ₀ of the radio wave source.
Although the peak of the two-dimensional correlation value ccf (τ, f) may be low as described above, the accurate position is not determined from the two-dimensional correlation value ccf (τ, f). For the purpose of limiting the radio wave source position candidate range, as long as a peak is provided for use in rough positioning of the three-dimensional position, the positioning accuracy is not deteriorated.

When the coarse positioning unit 21 roughly measures the three-dimensional position of the radio wave source, the radio wave source position candidate range setting unit 22 converts the surrounding range including the three-dimensional position into the radio wave source position candidate range (the radio wave source may exist). The radio wave source position candidate range is output to the candidate position setting unit 1.
When the candidate position setting unit 1 receives the radio source position candidate range from the radio source position candidate range setting unit 22, the candidate position setting unit 1 divides the region indicated by the radio source position candidate range into a grid shape, and the radio source exists in each divided region. possibility is to set a certain candidate position p _c.
Then, the output from a plurality of candidate positions p _c, yet any candidate position p _c is not selected Select one the movement compensation quantity calculation section 2.
Since the following processing contents are the same as those in the first to third embodiments, description thereof will be omitted.

As is apparent from the above, according to the fourth embodiment, the received signals s ₁ (t) and s ₂ (t) related to the radio waves received by the satellites # 1 and # 2 and the satellites # 1 and # 2 A position where the radio wave source exists by calculating a two-dimensional correlation value between the received signals s ₁ (t) and s ₂ (t) using the orbit information and detecting a peak of the two-dimensional correlation value. The radio source position candidate range setting unit 22 sets a range around the position roughly positioned by the coarse positioning unit 21 as a radio source position candidate range, and the radio source position candidate. Since the range is output to the candidate position setting unit 1, the search range of the position of the radio wave source is limited, and the calculation load of the positioning device can be reduced.

Embodiment 5 FIG.
In the fourth embodiment, the range around the position roughly measured by the coarse positioning unit 21 is set as the radio wave source position candidate range. However, there are a plurality of two-dimensional correlation value peaks due to the influence of ambiguity. In some cases, a plurality of positions where the radio wave source is detected are roughly measured.
When a plurality of positions are roughly measured in this way, the radio wave source position candidate range setting unit 22 sets a range around each position roughly measured by the coarse positioning unit 21 as a radio wave source position candidate range. To do.
In this case, the candidate position setting unit 1 divides the areas indicated by the plurality of radio source position candidate ranges set by the radio source position candidate range setting unit 22 in a grid shape, and the radio sources exist in the respective divided areas. set the candidate position p _c where there is likely to be.
Thereby, although the search range of the position of the radio wave source is wider than that of the fourth embodiment, the search range of the position of the radio wave source can be limited as compared with the first to third embodiments. Also, the ambiguity position can be eliminated.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  1 candidate position setting section (candidate position setting means), 2 movement compensation amount calculation section (arrival time calculation means), 3 received signal movement compensation section (received signal compensation means), 4 inner product value calculation section (inner product value calculation means), 5 all candidate position processing end determination unit, 6 positioning result output unit (positioning result output unit), 11 correlation value calculation unit (two-dimensional correlation value calculation unit), 12 peak detection unit, 13 all candidate position processing end determination unit, 14 Positioning result output unit (positioning result output unit), 21 Coarse positioning unit (coarse positioning unit), 22 Radio wave source position candidate range setting unit (candidate position setting unit), 51 Correlation value calculation unit, 52 Peak detection unit, 53 Positioning unit .

Claims (4)

  Candidate position setting means for setting a plurality of candidate positions where a radio wave source having an unknown position may exist, and the radio wave source exists at each candidate position set by the candidate position setting means. The arrival time calculation means for calculating the time when the radio wave transmitted from the radio wave source arrives at a plurality of satellites and the arrival time calculated by the arrival time calculation means are received by the plurality of satellites. Reception signal compensation means for compensating a reception signal related to radio waves, inner product value calculation means for calculating an inner product value between a plurality of reception signals compensated by the reception signal compensation means, and a plurality of values set by the candidate position setting means A positioning result output unit that specifies a candidate position where the inner product value calculated by the inner product value calculating means is the largest among the candidate positions and outputs the candidate position as a positioning result of the radio wave source. Positioning device provided with a door.   Candidate position setting means for setting a plurality of candidate positions where a radio wave source having an unknown position may exist, and the radio wave source exists at each candidate position set by the candidate position setting means. The arrival time calculation means for calculating the time when the radio wave transmitted from the radio wave source arrives at a plurality of satellites and the arrival time calculated by the arrival time calculation means are received by the plurality of satellites. A reception signal compensation means for compensating a reception signal related to a radio wave; a two-dimensional correlation value calculation means for calculating a two-dimensional correlation value between a plurality of reception signals compensated by the reception signal compensation means; and the candidate position setting means. Among the set candidate positions, a candidate position where the two-dimensional correlation value calculated by the two-dimensional correlation value calculating means is maximized is specified, and the candidate position is set as a positioning result of the radio wave source. Positioning device and a positioning result output means for outputting. By using a received signal related to radio waves received by a plurality of satellites and orbit information of the satellite, a two-dimensional correlation value between the plurality of received signals is calculated, and a peak of the two-dimensional correlation value is detected. Coarse positioning means for coarse positioning of the position where the
The candidate position setting means divides an area around the position roughly measured by the coarse positioning means, and sets each divided area to a plurality of candidate positions where the radio wave source may exist. The positioning device according to claim 1 or 2, characterized in that When two or more two-dimensional correlation value peaks are detected due to the influence of ambiguity, and the position where the radio wave source is present is roughly measured by the coarse positioning means,
The candidate position setting means divides each of the areas around the plurality of positions roughly measured by the rough positioning means, and each of the divided areas includes a plurality of candidate positions where the radio wave source may exist. The positioning device according to claim 3, wherein the positioning device is set as follows.

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