JP2012202698A - Time difference orientation detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a time difference orientation detection device which performs orientation detection with high precision without generating ambiguity of an orientation.SOLUTION: An authorization range setting part 315 sets an authorization range μ in which a time difference τc in pulse arrival time between antennas 11a, 11c is recognized as the time difference τc in pulse arrival time associated with the same pulse signal based upon a distance L between the antennas 11a, 11c, a pulse arrival orientation θ and a radio wave propagation speed C by a first signal processing part 2, and an azimuth error Δθ by an orientation error calculation part 314. A time difference determination part 316 determines the time difference τc in pulse arrival time which satisfies the recognition range μ by the recognition range setting part 315 among the time difference τc in pulse arrival time by the time difference detection part 311. A second orientation calculation part 32 calculates a pulse arrival orientation θ at which ambiguity of an orientation is not generated with high precision based upon the time difference τc in pulse arrival time which satisfies the recognition range μ, the distance between the antennas 11a, 11c, and the radio wave propagation speed C.

Description

  The present invention relates to a time difference azimuth detection device that receives radio waves coming from a pulse generation source such as a radar device using two or more antennas, and detects the direction of the pulse generation source from the time difference between pulse arrival times.

  As a conventional time difference azimuth detection device, two reception systems are arranged at a predetermined distance, and the signal processing unit detects the pulse arrival direction based on the pulse arrival times of the pulse signals received from the two reception systems. There is something.

  The two reception systems include an antenna that receives a pulse signal and a pulse detection unit that obtains a pulse arrival time for each pulse signal received by the antenna, and the signal processing unit has a pulse arrival time by the two reception systems. A time difference calculation unit for obtaining a time difference between the two, a distance between the antennas of the two receiving systems, and a direction calculation unit for obtaining a pulse arrival direction based on a radio wave propagation speed of the pulse signal. .

  As a publicly known document disclosing such a conventional time difference azimuth detecting device, there is the following Patent Document 1. This time difference azimuth detection device improves the accuracy of time difference azimuth detection without increasing the device scale by performing statistical processing for each reception system for multiple pulse arrival times related to a series of pulse signals by each reception system. ing.

JP 2003-215225 A

  By the way, as a method for improving the accuracy of time difference azimuth detection, one is a method for accurately calculating the time difference between incoming signals received by two antennas as in Patent Document 1, and the other is two methods for receiving two. There is a method of increasing the antenna distance.

FIG. 7 is a diagram showing a change in the time difference τ of the pulse arrival time due to a change in the distance d between the two antennas 11a and 11b in the time difference azimuth detection.
As shown in FIG. 7, even if the pulse signals arrive from the same direction and the distance d between the two antennas 11a and 11b is large, the time difference between the pulse arrival times detected by the two antennas 11a and 11b. τ increases. Since the error component included in the time difference τ does not depend on the distance d between the antennas 11a and 11b, the time difference τ with respect to the error component increases, and the accuracy of direction detection is improved.

Thus, the greater the distance between the two antennas 11a and 11b, the more accurate the direction finding. However, as shown in FIG. 8, when the pulse repetition interval (PRI) of the incoming pulse signal is smaller than the time difference τ between the pulse arrival times received by the two antennas 11a and 11b, Instead of the time difference τ between the same pulse signals, an erroneous calculation time difference τ _error with one or more previous pulses is calculated, and ambiguity (ambiguity ambiguity) occurs in the detected direction.
A method of suppressing the occurrence of azimuth of azimuth by increasing the pulse repetition period of the incoming pulse signal is also conceivable, but in this case, the responsiveness of azimuth detection is lowered.

  Since the conventional time difference azimuth detecting device is configured as described above, when the pulse repetition period of the incoming pulse signal is smaller than the time difference τ of the pulse arrival times received by the two antennas 11a and 11b. If ambiguity occurs in the detected direction, and conversely, if the pulse repetition period of the incoming pulse signal is increased to suppress the generation of direction ambiguity, the response of direction detection is There was a problem to be reduced.

  The present invention has been made to solve the above-mentioned problems, and does not generate azimuth ambiguity without increasing the pulse repetition period to reduce azimuth detection responsiveness. An object of the present invention is to obtain a time difference azimuth detecting device for detecting the azimuth.

  The time difference azimuth detecting apparatus according to the present invention includes a time difference detection unit that obtains a time difference between pulse arrival times by two receiving systems arranged at a long distance, and a first pulse arrival direction by a first signal processing unit. An azimuth error calculation unit for obtaining an azimuth error included in one pulse arrival azimuth, and a pulse signal having the same time difference between pulse arrival times by two reception systems arranged at a long distance based on the azimuth error by the azimuth error calculation unit An authorized range setting unit that obtains an authorized range that is recognized as a time difference between pulse arrival times, and a pulse arrival time that satisfies the authorized range obtained by the authorized range setting unit of the time difference between pulse arrival times obtained by the time difference detector. The time difference determination unit for obtaining the time difference between the two, and the time difference of the pulse arrival times by the time difference determination unit, the antennas of the two receiving systems arranged at a long distance Distance, and is obtained by a orientation calculation unit for obtaining a second pulse arrival direction based on the radio wave propagation speed of the pulse signal.

According to the present invention, since the final pulse arrival direction is obtained from two receiving systems arranged at a long distance, the direction can be detected with high accuracy.
Even if the pulse repetition period of the incoming pulse is smaller than the time difference between the pulse arrival times, the pulse arrival direction can be obtained from the time difference between the pulse arrival times for the same pulse signal. Therefore, there is an effect that the direction can be detected with high accuracy without increasing the pulse repetition period and reducing the response of the direction detection, and without generating the direction ambiguity.

It is a block diagram which shows the structure of the time difference azimuth | direction detection apparatus by Embodiment 1 of this invention. It is a block diagram which shows the detailed structure of a 2nd time difference calculation part. It is explanatory drawing which shows the azimuth | direction error reference table by a short-distance antenna. It is explanatory drawing which shows the example which three antennas receive a series of pulse signals. It is explanatory drawing which shows the azimuth | direction error contained in the pulse arrival azimuth | direction measured by the time difference of the pulse arrival time of two antennas arrange | positioned at a short distance, and the accreditation range calculated | required based on the azimuth | direction error. It is a block diagram which shows the structure of the time difference azimuth | direction detection apparatus by Embodiment 2 of this invention. It is explanatory drawing which shows the change of the time difference of the pulse arrival time by the change of the distance between two antennas. It is explanatory drawing which shows the generation principle of ambiguity.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a time difference azimuth detecting apparatus according to Embodiment 1 of the present invention. This time difference azimuth detecting device includes three receiving systems 1A to 1C, a first signal processing unit 2, and a second signal processing unit 3.

  In the receiving system 1A, the antenna 11a receives a series of pulse signals, and the pulse detector 12a adds and records a pulse arrival time (TOA: Time Of Arrival) for each pulse signal received by the antenna 11a. is there.

  Similarly, in the receiving system 1B, the antenna 11b receives a series of pulse signals, and the pulse detector 12b adds and records a pulse arrival time for each pulse signal received by the antenna 11b.

  Similarly, in the receiving system 1C, the antenna 11c receives a series of pulse signals, and the pulse detection unit 12c records a pulse arrival time for each pulse signal received by the antenna 11c.

  However, as shown in FIG. 4 to be described later, the antennas 11a to 11c are arranged on the same straight line and receive a series of pulse signals coming from the same pulse generation source.

Further, the antennas 11a and 11b are arranged with a small distance d so as not to cause azimuth of azimuth, and the antennas 11a and 11c are arranged with a large distance L in order to improve the accuracy of azimuth detection. Is done.
Furthermore, the pulse detection unit 12b of the reception system 1B and the pulse detection unit 12c of the reception system 1C are time-synchronized with the pulse detection unit 12a of the reception system 1A.

  The first signal processing unit 2 has a low-accuracy and low-accuracy azimuth error but does not generate an azimuth azimuth based on the pulse arrival time for each pulse signal received by the receiving systems 1A and 1B. The direction is determined.

In the first signal processing unit 2, the first time difference calculation unit 21 calculates the time difference between the pulse arrival times recorded for each pulse signal by the reception systems 1A and 1B.
The first azimuth calculation unit 22 calculates the pulse arrival azimuth based on the time difference between the pulse arrival times, the distance between the antennas 11a and 11b of the receiving systems 1A and 1B, and the radio wave propagation speed of the pulse signal. is there.

  The second signal processing unit 3 includes a pulse arrival time for each pulse signal by the receiving systems 1A and 1C and an azimuth error by the first signal processing unit 2 and has low accuracy, but the azimuth of the azimuth is low. Based on the pulse arrival azimuth that does not occur, the pulse arrival azimuth that does not generate azimuth of the azimuth with high accuracy is obtained.

In the second signal processing unit 3, the second time difference calculating unit 31 calculates a time difference between the pulse arrival times recorded for each pulse signal by the receiving systems 1A and 1C. Further, the certified range is obtained so that only the time difference of the pulse arrival times related to the same pulse signal among the calculated time differences of the pulse arrival times is certified. This accreditation range is obtained from the azimuth error obtained from the azimuth error included in the pulse arrival azimuth based on the pulse arrival azimuth by the first signal processing unit 2.
In addition, the second azimuth calculation unit 32 calculates the pulse arrival azimuth based on the time difference between the pulse arrival times satisfying the certified range, the distance between the antennas 11a and 11c of the receiving systems 1A and 1C, and the radio wave propagation speed of the pulse signal. Is to be calculated.

  FIG. 2 is a block diagram showing a detailed configuration of the second time difference calculation unit. The second time difference calculation unit 31 includes a time difference detection unit 311, a pulse frequency calculation unit 312, an azimuth error reference table storage unit 313, an azimuth error calculation unit 314, a certified range setting unit 315, and a time difference determination unit 316. It consists of.

  The time difference detection unit 311 calculates a time difference between pulse arrival times by the receiving systems 1A and 1C. The pulse frequency calculation unit 312 calculates the pulse frequency based on the pulse arrival time by the reception system 1A.

  The azimuth error reference table storage unit 313 stores in advance an azimuth error reference table including azimuth errors according to the pulse frequency and the pulse arrival azimuth. FIG. 3 is an explanatory diagram showing an azimuth error reference table using a short-range antenna. Further, the azimuth error calculation unit 314 uses the azimuth error reference table stored in the azimuth error reference table storage unit 313 based on the pulse frequency by the pulse frequency calculation unit 312 and the pulse arrival azimuth by the first signal processing unit 2. This is to extract the azimuth error.

  The authorized range setting unit 315 determines the distance between the antennas 11a and 11c of the receiving systems 1A and 1C, the pulse arrival direction by the first signal processing unit 2, the radio wave propagation speed of the pulse signal, and the direction error by the direction error calculation unit 314. The accreditation range is set based on this. Further, the time difference determination unit 316 determines a time difference between the pulse arrival times that satisfies the certified range set by the certified range setting unit 315 among the time differences between the pulse arrival times set by the time difference detection unit 311.

  In addition, about the structure except the antennas 11a-11c of each structure shown in FIG. 1 and FIG. 2, you may make it implement | achieve a function with hardware, such as a semiconductor circuit board which mounts a microcomputer. Further, the function may be realized by software such as a program in which processing contents are described is stored in a memory of a computer, and a CPU of the computer executes the program stored in the memory.

Next, the operation will be described.
First, based on FIG. 4 and FIG. 5, the principle of the time difference azimuth detecting apparatus in the first embodiment will be described.
FIG. 4 shows an example in which three antennas 11a to 11c receive a series of pulse signals.

と求められる。 First, the pulse arrival azimuth θ is obtained from the time difference τb of the pulse arrival time between the antennas 11a and 11b, which has a small distance between the antennas. If the radio wave propagation speed of the pulse is C, the time difference τb is

Is required.

  However, in this case, since the distance d between the antennas is small, the measurement accuracy of the time difference τb of the pulse arrival time is not good, and the direction finding accuracy is not good. However, no ambiguity occurs in the detected direction.

と求められる。 Next, the pulse arrival direction θ is obtained from the time difference τc of the pulse arrival time between the antennas 11a and 11c, which has a large distance between the antennas. The time difference τc is

Is required.

  In this case, since the distance L between the antennas is large, the measurement accuracy of the time difference τc of the pulse arrival times is good, and the accuracy of the direction finding is also good. However, ambiguity occurs in the detected direction.

  Therefore, first, the pulse arrival azimuth θ is obtained from the time difference τb of the pulse arrival time between the antennas 11a and 11b where the distance between the antennas is small. The pulse arrival azimuth θ obtained here includes an azimuth error and is low in accuracy, but does not generate azimuth azimuth.

FIG. 5 shows the azimuth error Δθ included in the pulse arrival direction θ due to the time difference τb of the pulse arrival time between the antennas 11a and 11b.
Here, the azimuth error Δθ varies depending on the pulse frequency f and the pulse arrival azimuth θ.

  In the first embodiment, after manufacturing the time difference azimuth detecting device, tests and operations are performed, and the azimuth error Δθ is measured for each pulse frequency f and for each pulse arrival azimuth θ, and recorded in advance as a parameter.

  FIG. 3 shows the orientation error reference table. In this azimuth error reference table, the azimuth error Δθ can be extracted based on the received pulse frequency f and the pulse arrival azimuth θ measured by the time difference τb between the pulse arrival times of the two antennas 11a and 11b. .

である。 Returning to FIG. 5, from this azimuth error Δθ, the time error Δτc affecting the time difference τc of the pulse arrival time between the antennas 11a and 11c arriving at the antenna 11c is

It is.

と求められる。 Therefore, based on this time error Δτc, the recognized range μ in which the time difference τc of the pulse arrival times between the antennas 11a and 11c is recognized as the time difference of the pulse arrival times for the same pulse signal is

Is required.

  Therefore, when the time difference τc of the pulse arrival times between the antennas 11a and 11c satisfies the certified range μ of the above equation (6), it is recognized that this is the time difference of the pulse arrival times for the same pulse signal. If the pulse arrival azimuth θ is obtained using the time difference τc satisfying the certified range μ in 6), the azimuth can be detected with high accuracy without generating the ambiguity of the azimuth.

Next, a specific operation of the time difference azimuth detecting apparatus according to the first embodiment will be described with reference to FIGS.
In FIG. 1, the antennas 11 a to 11 c of the receiving systems 1 </ b> A to 1 </ b> C receive a series of pulse signals coming from the same pulse generation source, as shown in FIG. 4. The pulse detectors 12a to 12c of the reception systems 1A to 1C add and record the pulse arrival times TOAa to TOAc for each pulse signal received by the antennas 11a to 11c.

  In the first signal processing unit 2, the first time difference calculation unit 21 calculates the time difference τb between the pulse arrival times TOAa and TOAb by the reception systems 1A and 1B. Further, the first azimuth calculation unit 22 calculates the time difference τb between the pulse arrival times, the distance d between the antennas 11a and 11b of the receiving systems 1A and 1B, and the radio wave propagation velocity C of the pulse signal according to the above equation (2). Based on this, a pulse arrival azimuth θ that includes an azimuth error and has low accuracy but does not generate azimuth of azimuth is calculated.

  In FIG. 2, the time difference detector 311 of the second time difference calculator 31 calculates the time difference τc between the pulse arrival times TOAa and TOAc by the receiving systems 1A and 1C. The pulse frequency calculation unit 312 calculates the pulse frequency f based on the pulse arrival time TOAa by the reception system 1A. Further, the azimuth error calculation unit 314 is stored in the azimuth error reference table storage unit 313 based on the pulse frequency f by the pulse frequency calculation unit 312 and the pulse arrival azimuth θ by the first signal processing unit 2. The azimuth error Δθ included in the pulse arrival azimuth θ is extracted from the azimuth error reference table shown in FIG.

  The accreditation range setting unit 315 includes the distance L between the antennas 11a and 11c of the receiving systems 1A and 1C, the pulse arrival direction θ by the first signal processing unit 2, the radio wave propagation velocity C of the pulse signal, Then, the azimuth error Δθ by the azimuth error calculation unit 314 is applied to set a certified range μ in which the time difference τc between the pulse arrival times of the two antennas 11a and 11c is recognized as the time difference between the pulse arrival times for the same pulse signal.

  Further, the time difference determination unit 316 determines the time difference τc of the pulse arrival times that satisfies the certified range μ by the certified range setting unit 315 among the time differences τc of the pulse arrival times by the time difference detection unit 311.

  In FIG. 1, the second azimuth calculation unit 32 uses the above equation (4) to calculate the time difference τc of the pulse arrival times satisfying the certified range μ, the distance L between the antennas 11a and 11c of the receiving systems 1A and 1C, and the pulse Based on the radio wave propagation velocity C of the signal, a pulse arrival direction θ that does not generate a direction ambiguity with high accuracy is calculated.

  As described above, according to the first embodiment, even when the pulse repetition period of the incoming pulse is smaller than the time difference between the pulse arrival times, the pulse arrival direction is determined by the time difference between the pulse arrival times for the same pulse signal. Can be requested. Therefore, it is possible to detect the azimuth with high accuracy without increasing the pulse repetition period and lowering the responsiveness of the azimuth detection and without generating the ambiguity of the azimuth.

  Further, the azimuth error included in the pulse arrival azimuth from the azimuth error reference table stored in the azimuth error reference table storage unit 313 based on the pulse frequency by the pulse frequency calculation unit 312 and the pulse arrival azimuth by the first signal processing unit 2 Can be easily extracted.

  Further, the authorized range setting unit 315 is based on the above formula (6), the distance between the antennas 11a and 11c of the receiving systems 1A and 1C, the specified value such as the radio wave propagation speed of the pulse signal, and the first signal processing unit 2 By simply applying the pulse arrival azimuth and the azimuth error by the azimuth error calculation unit 314, a highly accurate certified range can be set easily.

  In the first embodiment, in FIG. 4, two receiving systems arranged at a short distance among the three receiving systems 1A to 1C are defined as 1A and 1B, and two receiving systems arranged at a long distance are used. 1A and 1C. However, the two receiving systems arranged at a long distance may be 1B and 1C. In this case, L in each equation may be (Ld).

  In the first embodiment, the azimuth error reference table storage unit 313 stores the azimuth error reference table including the azimuth errors according to the pulse frequency and the pulse arrival azimuth, as shown in FIG. . However, instead of this pulse frequency, an azimuth error reference table composed of azimuth errors according to the pulse repetition period and the pulse arrival azimuth may be stored. In this case, a pulse repetition period calculation unit that calculates a pulse repetition period may be provided instead of the pulse frequency calculation unit 312.

Embodiment 2. FIG.
In the first embodiment, the time difference azimuth detection apparatus applied when time difference azimuth detection is performed on a single platform has been described.
In the second embodiment, each constituent unit of the time difference azimuth detecting device in the first embodiment is separated into two devices, and wireless communication is performed between the two devices, so that the degree of freedom of installation is increased and the distance is increased. It can be expected to further improve the accuracy of direction detection by installing it at a distance.

  FIG. 6 is a block diagram showing a configuration of a time difference azimuth detecting apparatus according to Embodiment 2 of the present invention. The time difference azimuth detecting device described in the first embodiment is provided separately in the first and second devices 401 and 402.

In FIG. 6, the first device 401 includes the reception systems 1 </ b> A and 1 </ b> B and the first signal processing unit 2, and the second device 402 includes the reception system 1 </ b> C and the second signal processing unit 3.
Further, the first device 401 includes a transmitter 403 that transmits the pulse arrival time TOAa by the reception system 1A and the pulse arrival direction θ by the first signal processing unit 2, and the second device 402 has a transmission A receiver 404 that receives the pulse arrival time TOAa and the pulse arrival direction θ from the machine 403 and supplies the pulse arrival direction θ to the second device 402.

As described above, according to the second embodiment, since the first and second devices 401 and 402 can be installed at free locations, the degree of freedom of installation as a time difference azimuth detection device is increased. be able to.
Further, if the first and second devices 401 and 402 are installed farther away than the distance L, for example, it is possible to detect the direction with higher accuracy.
In this case as well, the antennas 11a to 11c are arranged on the same straight line, and the antennas 11a and 11b are arranged with a short distance d so as not to cause azimuth of azimuth.

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

  1A to 1C reception system, 2 first signal processing unit, 3 second signal processing unit, 11a to 11c antenna, 12a to 12c pulse detection unit, 21 first time difference calculation unit, 22 first azimuth calculation unit, 31 Second time difference calculation unit, 32 Second direction calculation unit, 311 Time difference detection unit, 312 Pulse frequency calculation unit, 313 Direction error reference table storage unit, 314 Direction error calculation unit, 315 Certified range setting unit, 316 Time difference determination Part 401 first device 402 second device 403 transmitter 404 receiver.

Claims (4)

Three receiving systems each receiving a series of pulse signals respectively arranged at predetermined distances and coming from the same pulse generation source;
A first signal processing unit for obtaining a first pulse arrival direction based on pulse arrival times received by two reception systems arranged at a short distance of the three reception systems;
A second signal processing unit for obtaining a second pulse arrival direction based on a pulse arrival time received by two reception systems arranged at a long distance among the three reception systems;
The above three receiving systems are
An antenna for receiving a pulse signal;
A pulse detector for obtaining a pulse arrival time for each pulse signal received by the antenna,
The second signal processing unit includes:
A time difference detection unit for obtaining a time difference between pulse arrival times by two receiving systems arranged at a long distance;
An azimuth error calculation unit for obtaining an azimuth error included in the first pulse arrival direction based on the first pulse arrival direction by the first signal processing unit;
Based on the azimuth error by the azimuth error calculation unit, a certification range is obtained for obtaining a certification range in which the time difference between the pulse arrival times by two receiving systems arranged at a long distance is recognized as the time difference between the pulse arrival times for the same pulse signal. And
A time difference determination unit for obtaining a time difference of pulse arrival times satisfying a certified range obtained by the certified range setting unit of time differences of pulse arrival times obtained by the time difference detection unit;
An azimuth calculation unit for obtaining a second pulse arrival direction based on the time difference of the pulse arrival times by the time difference determination unit, the distance between the antennas of two receiving systems arranged at a long distance, and the radio wave propagation speed of the pulse signal; A time difference azimuth detecting device characterized by comprising. A first apparatus including the two reception systems arranged at a short distance, and the first signal processing unit;
One receiving system not included in the first device among the two receiving systems arranged at a long distance, and a second device including the second signal processing unit;
The first pulse arrival direction determined by the first signal processing unit and the pulse arrival time by the other reception system of the two reception systems disposed in the long distance included in the first device A transmitter to transmit,
The time difference according to claim 1, further comprising: a receiver that receives a pulse arrival time and a first pulse arrival direction by the other receiving system from the transmitter and supplies the first pulse arrival direction to the second device. Direction finding device. The second signal processing unit includes:
A pulse frequency calculation unit for obtaining a pulse frequency based on a pulse arrival time by the reception system;
An azimuth error reference table storage unit that stores in advance an azimuth error reference table composed of azimuth errors according to the pulse frequency and the pulse arrival azimuth;
The azimuth error calculation unit
Extracting an azimuth error from the azimuth error reference table stored in the azimuth error reference table storage unit based on the pulse frequency by the pulse frequency calculation unit and the first pulse arrival azimuth by the first signal processing unit; The time difference azimuth detecting apparatus according to claim 1 or 2, characterized in that: The above accreditation range setting section
Based on the distance between the antennas of the two receiving systems arranged at a long distance, the first pulse arrival direction by the first signal processing unit, the radio wave propagation speed of the pulse signal, and the direction error by the direction error calculation unit The time difference azimuth detecting device according to any one of claims 1 to 3, wherein an authorized range is obtained.

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