JP3353991B2 - Angle detecting device, angle detecting method, and radar device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angle information detecting device for detecting angle information of a target such as a flying object.

[0002]

2. Description of the Related Art A conventional angle information detecting apparatus obtains angle information of a direction in which a target exists and a height (elevation angle) direction by using a so-called known monopulse method. In particular, when measuring the elevation angle of a low-elevation angle target using this monopulse method, the angle of arrival of a direct wave from the target and the reflected wave (hereinafter referred to as a multipath reflected wave) that is received after being reflected once on the ground or sea surface Since the difference between the angles of arrival is small and two waves interfere with each other, an angle information detection method based on this is used.

When the number of arriving waves is one, S = Δ / Σ of the sum / difference division signal in the monopulse angle measurement method is expressed by the following equation (1). S = S ₁ (f, θ ₀ , θ) (1) f: Operating frequency θ ₀ : Direction of main beam θ: Arrival angle This is a real function, and if f and θ ₀ at the time of observation are determined, It is represented by equation (2). S = S ₁ (θ) (2) Assuming that the value at the time of observation is the observed value S _x with respect to the above general formula, θ _x can be obtained from the following formula (3) by calculating backward from this S _x . θ _x = S ₁ ⁻¹ (S _x ) (3) By calculating the expression (3), the arrival angle θ _x can be obtained. Generally, this S ₁ (θ) is nonlinear with respect to θ as shown in FIG. By the way, when there are two incoming waves, S is given by the following equation (4). S = S ₂ (f, θ ₀ , S ₁ (θ _t ), S ₁ (θ _i ), φ, ρ) (4) θ _t : angle of arrival of direct wave θ _i : angle of arrival of reflected wave φ: direct The phase difference ρ between the wave and the reflected wave: the amplitude ratio between the direct wave and the reflected wave, that is, a complex function, which cannot be handled by the conventional monopulse method. In addition, when the real part or the absolute value is obtained from the observed complex number S and converted into a real number to apply the monopulse method, a large error occurs.

The following is a second conventional example in which this is improved. FIG. 20 shows, for example, Samuel M. She
rman; "MonopulsePrinciples
and Techniques ", Artech H
FIG. 2 is a basic configuration diagram of a conventional angle information detection device shown in “use”, in which transmission and reception are separated for simplicity of description. In FIG. 20, 1 is a transmitting antenna, 2 is a stabilized local oscillator, 3 is a coherent oscillator, 4 is a frequency converter, 5 is a timing generator, 6 is a receiving antenna, 7 is a sum signal generator, and 8 is a difference signal generator. Means, 9 is a mixer, 10 is phase detection means, 11 is π / 2 phase shift means, 1
2 is an A / D converter, 13 is a complex divider, and 14 is a complex angle converter. FIG. 21 shows the outputs of the receiving antennas 6a and 6b, the sum signal generating means 7 and the difference signal generating means 8 of FIG. 20 with respect to the elevation angle, and 103a and 103b are the outputs of the receiving antennas 6a and 6b of FIG.
Reference numeral 4 denotes an output of the sum signal generation means 7 which is the sum of 103a and 103b, and reference numeral 105 denotes an output of the difference signal generation means 8 which is a difference between 103a and 103b. FIG. 22 shows the complex divider 13 shown in FIG. 20 when the direct wave interferes with the multipath reflected wave.
100b is a locus drawn on the complex plane by the output of the complex division means 13 in the absence of noise or the like according to the elevation angle when the target moves at a certain altitude, and 101e, 101f , 101g are complex division means 13 including noise obtained when the target is at a certain position.
This is the observed value output of. 106a, 106b and 106c,
106d and 106e are the observation output 101e, 1
This is the selected point on the locus 100b closest to 01f and 101g.

The basic concept of the second conventional example is as follows. Fig. 2 for multi-pulse considering reflected wave
For the model as shown in FIG. 3, the conventional monopulse method is approximated by the following equation (5). S = S ₁ (θ) ≒ αθ (5) That is, it is assumed that the observation is performed in the shaded portion in FIG. Further, the following equations (6) to (8) are assumed. θ _i = −θ _t (6)

[0006]

(Equation 1)

Ρ ≒ 1 (8) As a result, S can be represented by the complex function of equation (9) corresponding to the following input: S = S ₂₁ (f, θ ₀ , θ _t ) (9) Then, for each of f and θ ₀ at the time of observation, S = S ₂₁ (θ _t ) (10) is prepared, and a complex number _Sc is obtained as an observation value. When obtained,
_Assuming that it can be expressed by the following equation (11), the value S _cx closest to the value is
_Is obtained as the target elevation angle. S _c ≒ S _cx = S ₂₁ (θ _cx ) (11) That is, as shown in FIG. 22, f
Complex function S ₂₁ (θ for the advance angle of elevation for each θ ₀ and
The locus 100b of _t ) is tabulated and stored, and a point 106a on the locus closest to the observation result point 101e is selected, and the elevation angle at that point is set as the target elevation angle.

The operation of the angle information detecting device will be described with reference to FIG. The signal generated by the stabilized local oscillator 2 and the coherent oscillator 3 is input to the frequency conversion unit 4 to be a high-frequency pulse, and the transmission antenna is controlled by the timing generation unit 5 based on the phase information of the coherent oscillator 3. 1 radiated into the search space. A reflected signal from a target located at a certain position in the search space is received by two receiving antennas 6a and 6b which are directly or once reflected on the ground or the sea surface, and which are arranged vertically to the ground. The outputs 103a and 103 of the two receiving antennas 6a and 6b as shown in FIG.
3b is a sum signal generating means 7 for outputting the sum component 104.
Is input to the difference signal generating means 8 which outputs the difference component 105. The outputs of the sum signal generation means 7 and the difference signal generation means 8 are output from the stabilized local oscillator 2 to the mixer 9.
The signals are converted into intermediate frequency (IF) signals at a and 9b. The outputs of the two mixers 9a and 9b are respectively based on the phase detection means 10a and 10c based on the output of the coherent oscillator 3.
To the signal of the in-phase component by the π / 2 phase shifter 11 based on the output of the coherent oscillator 3 by the phase detector 10b.
Is converted into a signal of an orthogonal component by 10d. The outputs of the phase detectors 10a to 10d are output from A / D converters 12a to 12d.
And is A / D converted and output. Outputs of the A / D converters 12a to 12d are input to a complex divider 13 and perform complex division Δ / Σ between a complex sum signal (hereinafter referred to as Σ) and a complex difference signal (hereinafter referred to as Δ). The result is output.

The complex angle conversion means 14 is a complex division means 13
The target elevation angle is obtained from the complex output of the above and is output. If the width of the beam formed by the receiving antenna 6, the direction of the beam nose, the height of the antenna, and the used frequency are known, the complex number Δ / Σ in a state where there is no disturbance due to noise or the like other than the multipath reflected wave. The values are plotted on the complex plane according to the elevation angle at which the target exists, as shown in FIG.
It can be understood in advance that a locus 100b is drawn. At this time, when a certain observation value 101e is obtained, the elevation angle corresponding to the closest selected point 106a is set as the target elevation angle. Therefore, the complex angle conversion means 14 uses the locus 100b shown in FIG.
(Hereinafter, referred to as a complex elevation trajectory) is obtained in advance, and a target elevation angle is obtained from the output of the complex division means 13 by the above-described means and output.

There is a third conventional example. JP-A-5-19
In 6725, the model as shown in FIG. 24 is assumed to have a range that can be handled by the conventional monopulse formula (5), and approximates formulas (12) to (14).

[0011]

(Equation 2)

Equation (4) can be expressed as follows. _{S = S 22 (f, h} t, h a, R, ρ) and (15) In this equation (15), the real part of _{S 22 R e (S 22)} , S
H _t is determined by using the following equation for the declination arg (S ₂₂ ).

[0013]

(Equation 3)

That is, instead of directly using the trajectory of the complex function with respect to the elevation angle on the complex plane, the target value is obtained by differentiating the argument of the complex function by a certain variable (time or frequency) and the value of the real part of the complex function. Ask for altitude. According to this method, even when the observation result is like the point 101f in FIG. 22 , the differential value of the argument from the point 107a to the point 107b and the point 107f
Since the differential value of the argument from c to the point 107d is different, the target altitude can be obtained without ambiguity.

Further, there is a fourth embodiment in which x and y values of the complex division of Δ / Σ are directly obtained by other means. This is Sym
onds-Smith proposed Radar-
Present & Future IEEE 1973 M
ULTI-FREQUENCYCOMPLEX-ANG
LE TRACKING OF LOW-LEVEL
ARGETS. According to this method, there is provided a means for controlling the amplitude so that S = S ₁ (θ) = θ (18) within a range in which the conventional monopulse method can be approximated by Expression (5). Then, the real part x and the imaginary part y of the equation (4) are expressed by: x = R _e (S ₂ ) = S ₂ r ₁ (f, θ ₀ , θ _t , θ _i , φ, ρ) (19) y = I _m (S ₂ ) = S ₂ i ₁ (f, θ ₀ , θ _t , θ _i , φ, ρ) (20) When focusing on φ, (x−C ₁ ) ² + y ² = r ₁ ² (cos ² φ + sin ² φ) = r ₁ ² (21), which is the center (C ₁ , 0) in the xy plane,
Which is the circle of form radius r _1. At this time, the center x coordinate C ₁ and the radius r ₁ are respectively the following functions. C ₁ = C ₁ (f, θ ₀ , θ _t , θ _i , ρ) (22) r ₁ = r ₁ (f, θ ₀ , θ _t , θ _i , ρ) (23) C ₁ and r ₁ Clearing the ρ ^{_{for, C 1 2 -r 1 2 +}} θ t · θ i = C 1 (θ t + θ i) obtaining the expression (24). Here, assuming a model as shown in FIG. 24, equations (12) and (1) are used for θ _t and θ _i in equation (24).
3) and performed a similar approximation since the following equation is obtained, C ₁
If r ₁ is determined, h _t can be obtained. This C ₁
And r ₁ , equation (26) holds because φ is a function like equation (26).

[0016]

(Equation 4)

It can be obtained from a plurality of x and y in equation (21) in which φ is changed by a plurality of different frequencies. Here, it is determined using the least squares method. That is,
The radius and center of the complex plane are obtained, and the altitude or angle to the target is obtained from these two values. Further, this conventional example requires the amplitude control of equation (18).

[0018]

In a radar, since the solid angle of the antenna beam is usually smaller than that of the observation area, the main beam must be directed in various directions in order to observe the entire observation area. For this reason, the angle information detecting device of the second conventional example has a problem that it is necessary to prepare a complex elevation trajectory for each main beam, and the observation values 101f and 10f in FIG.
In the case of 1g, 106b or 1
Since 06c, 106d or 106e is obtained, there is ambiguity. Particularly for a long-distance target, there is a problem that the target altitude calculated from the elevation angle of the target greatly changes due to the ambiguity. Further, in the third and fourth conventional examples, the range of the distance that can be handled is limited, and the reflection surface is assumed to be a flat surface. Therefore, there is a problem that the accuracy decreases when the distance increases. Further, the third conventional example is for obtaining a trajectory from a differential value, and requires a complicated calculation.
In the fourth conventional example, both the radius and the center of the complex circle are obtained,
There is a problem that the calculation for obtaining the altitude is required, the calculation takes time, and the amplitude control means is also required.

The present invention has been made in order to solve the above-mentioned problem. In this invention, S on the imaginary axis is obtained from a complex elevation trajectory, and the angle of attack is obtained from this. That is, an object of the present invention is to provide an angle information detecting device that accurately detects an angle at which a target exists regardless of the distance in a state where interference is caused by a multipath reflected wave.

[0020]

An angle detecting device according to the present invention comprises: a sum signal generating means for generating a sum component of a received signal; a difference signal generating means for generating a difference component of the received signal; Complex division means for mixing each signal of the above with a local oscillation signal, phase detecting with a coherent oscillation signal to obtain each quadrature phase component, and performing complex division from the obtained sum signal and difference signal of complex numbers, and this complex division Is a circle on the complex plane, and a plurality of complex division results corresponding to a plurality of received signals are on the circle. Angle conversion means for obtaining an angle from the center value of the output circle.

An angle detecting device according to the present invention comprises a transmitting means for transmitting a radio wave to a target at a different transmitting frequency with a variable frequency oscillator, and a sum component of a received signal which is a reflected wave of a transmitted signal output from the transmitting means. Sum signal generating means for generating;
A difference signal generating means for generating a difference component of the received signal; mixing the sum and the difference signal with a local oscillation signal; performing phase detection with a coherent oscillation signal; obtaining quadrature phase components; and summing the obtained complex numbers Complex division means for performing complex division from the signal and the difference signal, and assuming that the result of the complex division substantially forms a circle on a complex plane, and the results of the plurality of complex divisions corresponding to a plurality of reception signals corresponding to different transmission frequencies are A circle center calculating means for obtaining a center value of the circle as being on the circle, and an angle converting means for obtaining an angle from the center value of the circle output from the circle center calculating means are provided.

Still further, the circle center calculating means is a first circle center calculating means, and the second circle center calculating means for obtaining a circle center on a complex plane based on a complex division result by reception signals at different times. And input value selection means for comparing the output of the first circle center calculation means with the output of the second circle center calculation means to select an output which provides continuity of change from the previous observation value. The output of the input value selection means is provided to the angle conversion means.

Still further, the circle center calculating means is first circle center calculating means, and a complex division result by a received signal corresponding to a transmission signal having an oscillation frequency different from a transmission signal for the first circle center calculating means. The second circle center calculating means for obtaining the center of the circle on the complex plane based on the above, the output of the first circle center calculating means and the output of the second circle center calculating means are compared, and the continuous change from the previous observation value Input value selecting means for selecting an output which can provide the characteristic, and the output of the input value selecting means is provided to the angle converting means.

Further, each signal of the sum and difference of the received signals is phase-detected by a coherent oscillation signal to obtain each quadrature phase component, and further coherently integrated for a plurality of received signals to obtain a sum signal of a plurality of complex numbers. The first to n-th coherent integrating means for obtaining a difference signal, and the complex dividing means correspond to the output of the first to n-th coherent integrating means and generate a sum signal of a complex number obtained by each of the integrating means. First to n-th complex division means for performing complex division from the difference signal, wherein the circle center operation means determines that the result of each complex division substantially forms a circle on a complex plane, and corresponds to a plurality of reception signals corresponding to a plurality of reception signals. The corresponding first to n-th circle center calculation means for obtaining the center value of the circle on the assumption that the result of the complex division is on a circle, and further, the angle calculation means corresponds to the circle output of each circle center calculation means. Find angle from median 1 and the angle converter of the n.

Further, each of the sum and difference of the received signals is phase-detected with a coherent oscillation signal to obtain each quadrature phase component, and further coherently integrated for a plurality of received signals to obtain a sum signal of a plurality of complex numbers. The first to n-th coherent integrating means for obtaining a difference signal, and the complex dividing means correspond to the output of the first to n-th coherent integrating means and generate a sum signal of a complex number obtained by each of the integrating means. First to n-th complex division means for performing complex division from the difference signal, wherein the circle center operation means determines that the result of each complex division substantially forms a circle on a complex plane, and corresponds to a plurality of reception signals corresponding to a plurality of reception signals. It is assumed that the result of the complex division is on a circle, and the corresponding eleventh to n-th circle center calculation means for calculating the center value of the circle are based on the same complex division result by the received signals having different time or frequency. Zu 12 for determining the circle center in the complex plane
To the n2th circle center calculating means and the input selecting means,
The first input value selection means for comparing the outputs of the eleventh and twelfth circle center calculation means and selecting an output from which the continuity of the change from the previous observation value is obtained. To the n-th input selecting means for comparing the output with the circle center calculating means and selecting the same by the same configuration operation. Further, as the angle converting means, the center value of the circle corresponding to the first to n-th input selecting means First to n-th angle conversion means for obtaining an angle from the angle.

Further, a coherent integration means for phase-detecting the sum and difference signals of the received signals with a coherent oscillation signal to obtain each quadrature phase component and coherently integrate the signals, and a target for obtaining a target speed from the output of the coherent integration means There is provided a speed detecting means, and a timing control means for determining an interval of the observation time from the target speed calculated by the target speed detecting means, and the reception signal is observed at a timing determined by the control means.

Further, a coherent integration means for phase-detecting the sum and difference signals of the received signals with a coherent oscillation signal to obtain each quadrature phase component and coherently integrate the signals, and a target for obtaining a target speed from the output of the coherent integration means Speed detecting means, and frequency setting means for determining a use frequency interval of the transmission frequency from the target speed calculated by the target speed detecting means, and changing the transmission frequency of the transmission signal at the set frequency interval so as to perform observation. did.

Further, a plurality of sets of sum signal generation means, difference signal generation means, complex division means, circle center calculation means and angle conversion means are provided, and angles in different directions are obtained.

Further, a plurality of sets of frequency variable transmission means, sum signal generation means, difference signal generation means, complex division means, circle center calculation means and angle conversion means are provided, and the angles in different directions are changed by changing the oscillation frequency. I asked for it.

The method for detecting an angle according to the present invention comprises the steps of calculating and storing a division value of a difference signal of a received signal and a sum signal of the received signal as a function form with respect to an angle of arrival, assuming that there is no multipath reflected wave in the received signal. Calculating the difference signal and the sum signal from the actual received signal, further performing complex division from the obtained difference / sum signal, and performing the complex division of the real received signal to obtain an imaginary value and a real value a plurality of times. Steps to repeat,
A step of obtaining the center of a circle passing through each point from the imaginary and real values of the complex division result of the plurality of times, and a step of obtaining an angle of arrival by referring to the function form from the obtained value of the center of the circle Equipped.

According to the radar apparatus of the present invention, there is provided a transmitting antenna for emitting a transmitting radio wave for radar, a plurality of receiving antennas for receiving a receiving wave corresponding to the transmitting radio wave, and a sum for generating a sum component of the receiving signal. A signal generating means, a difference signal generating means for generating a difference component, and a signal obtained by mixing each signal of the sum and the difference with a local oscillation signal, performing phase detection with a coherent oscillation signal to obtain each quadrature phase component, and obtaining a complex number. Complex division means for performing complex division from the sum signal and the difference signal, and assuming that the result of this complex division draws a circle on a complex plane, the plurality of complex division results corresponding to a plurality of reception signals corresponding to different transmission frequencies. First calculating means for calculating the center value of the circle from
Angle conversion means for obtaining an angle from the center value of the circle output from the first calculation means, and display means for displaying the obtained angle are provided.

[0032]

According to the angle detecting device of the present invention, the complex division result of the sum signal and the difference signal of the received signals is output at least three times, and the center value of the complex circle is obtained from these values. Further, the angle is directly obtained from the center value of the circle on the real axis on the complex plane.

According to the angle detecting device of the present invention, the oscillation frequency is changed at least three times on the transmitting side, and a complex division result of the sum signal and the difference signal of the reception signals obtained correspondingly is obtained. The center value of the circle is obtained. Further, the angle is directly obtained from the center value of the circle on the real axis on the complex plane.

Further, a plurality of sets of the complex division result of the sum signal and the difference signal of the received signals are calculated with three or more operations as one set, and the central value of the complex circle is obtained from the continuity of the values of each set. . Further, the angle is directly obtained from the center value of the circle on the real axis on the complex plane.

Further, the oscillation frequency is changed three or more times on the transmitting side to form a set, and further, a plurality of sets are changed, and a correspondingly obtained complex division result of the sum signal and the difference signal of the received signals is obtained. From the continuity of each set of values, the center value of the complex circle is obtained. Further, the angle is directly obtained from the center value of the circle on the real axis on the complex plane.

In addition, the result of complex division of the sum signal and difference signal of the received signals for different targets at different Doppler frequencies is output at least three times in units of coherent integration means, and the central value of the complex circle is obtained from these values. Further, the angle of each target is directly obtained from the center value of the circle on the real axis on the complex plane.

In addition, for each coherent integration means, a plurality of sets of complex division results of the sum signal and the difference signal of the received signals of different Doppler frequencies for each target are calculated as a set of three or more sets. The central value of the complex circle is obtained from the continuity of the values. Further, the angle of each target is directly obtained from the center value of the circle on the real axis on the complex plane.

Further, a target speed signal is obtained, a reception timing is determined based on the speed, and a complex division result of the sum signal and the difference signal of the received signal is output at least three times. The center value of the circle is obtained. Further, the angle of each target is directly obtained from the center value of the circle on the real axis on the complex plane.

Further, a target speed signal is obtained, a transmission oscillation frequency is determined based on the speed, and a result of complex division of the sum signal and the difference signal of the received signal is output at least three times. Gives the center value of the complex circle. Further, the angle of each target is directly obtained from the center value of the circle on the real axis on the complex plane.

Also, a plurality of sets of angle detecting devices are provided,
By shifting the reception time, angles with the target with respect to the different planes can be obtained.

Further, a plurality of sets of angle detecting devices are provided,
The oscillating frequency is changed so that the corresponding received signal gives the angle to the target for each different plane.

According to the angle detecting method of the present invention, a signal of the difference and the sum of the received signals is obtained, and a complex division thereof is obtained.
The center value on the complex plane is obtained, and the angle is obtained from the function form when there is no multipath.

According to the radar apparatus of the present invention, a transmission radio wave is emitted from a transmission antenna, a reflected wave from a target is received from a reception antenna, a center value of a circle on a complex plane is obtained, an angle is obtained, and a display device is obtained. The goal is displayed in.

[0044]

[Embodiment 1] The basic concept of the present invention will be described. First, it is assumed that Equation (2) for a monopulse holds. Then, the real part x and the imaginary part y of the equation (4) are converted into the equation (2)
7) and (28). x = R _e (S ₂ ) = S ₂ r ₂ (f, θ ₀ , S ₁ (θ _t ), S ₁ (θ _i ), φ, ρ) (27) y = I _m (S ₂ ) = S ₂ i ₂ (f, θ ₀ , S ₁ (θ _t ), S ₁ (θ _i ), φ, ρ) (28) Now, focusing on φ, equation (29) is obtained. x ² + (y−C ₂ ) ² = r ₂ ² (cos ² φ + sin ² φ) = r ₂ ² (29) This is a form of a circle having a center (0, C ₂ ) of the xy plane and a radius r _2. It is. At this time, the center y coordinate C ₂ and the radius r ₂ are respectively the following functions. C ₂ = C ₂ (f, θ ₀ , S ₁ (θ _t ), S ₁ (θ _i ), ρ) (30) r ₂ = r ₂ (f, θ ₀ , S ₁ (θ _t ), S ₁ (Θ _i ), ρ) (31) where S ₁ (θ) = d (θ) / S (θ) (32) S (θ): Σ component at θ d (θ): Δ component at θ Then, C ₂ can be expressed by equation (33). Assuming that the value of ρ is small, C ₂ is given by equation (34).

[0045]

(Equation 5)

From the obtained S ₁ (θ _t ), θ _t can be obtained in the same manner as a normal monopulse. In other words, θ _t is required once the center. Since the center is the function represented by the equation (26) as in the fourth conventional example, when the target is moving, the center is observed a plurality of times at a certain interval to determine the center. It can be obtained from a plurality of x and y in Expression (29) in a state where the distance changes and φ changes. Next, a method for obtaining the center of a circle from the real part and the imaginary part of a plurality of observed Δ / Σ important in the present invention will be described. ^{_{Now, x n 2 + (y n}} -C) 2 = r 2 2 points if (35) holds for resulting complex observations x _n + jy _n observations _{(x 1, y 1),} (x 2, y ₂ ),

[0047]

(Equation 6)

From the above, C is determined. However, since y ₁ ≒ y ₂ may occur at the time of observation, the value obtained by Expression (36) may take an extreme value. Therefore, from a plurality of points (x _n , y _n ) {n = 1 to m, m ≧ 3}, C _n ｛n is obtained from equation (36) for all two points that can be combined.
= 1 to m, m ≧ 3}. Next, C _n ｛n = _{1 to} m,
m ≧ 3｝ is sorted and the middle value is set to C. By this processing, the possibility that the denominator takes an extreme value that appears due to being close to 0 is reduced. Numerical simulation was performed for three points. The conditions are the values shown in FIG. 3 and a model as shown in FIG. 4 is assumed. That is, the reflecting surface may be a spherical surface. For comparison, the results are shown in FIG. 5 together with the results of a normal monopulse method using the value of | Δ / Σ | under the same conditions. In FIG. 5, a solid line 122 is a result of the above-described processing, a dotted line 123 is a result of a normal monopulse method using | Δ / Σ |, and a dashed line 124 is a true value. The solid line shows a stable altitude close to the true altitude. When the error in the target distance range is obtained by the rms value, the error is about 1/5 as compared with the method using | Δ / Σ |.

Hereinafter, a circuit configuration of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of an angle information detection device according to one embodiment of the present invention. In FIG. 1, the novel parts are 15 first input value storage means, 16 first circle center calculation means, and 17 angle conversion means. Other components are the same as those shown in FIG. 20 of the conventional example. FIG. 2 shows the output of the complex divider 13 of FIG. 1 when the direct wave and the multipath reflected wave interfere with each other.
a is a complex elevation trajectory 101a to 101d according to the elevation angle when a long-distance target moves at a certain altitude and the output of the complex division means 13 when there is no noise or the like is obtained when the target is at a certain position. The observed value output 102 of the complex division means 13 including noise, etc., is the center of the circle when 100a is a circle. The circle center calculating means important in the present invention is:
This is for obtaining the center 102 in FIG.

This operation will be described with reference to the drawings. In FIG. 1, the operation up to the output of the complex division means 13 is the same as the conventional one. That is, the stabilized local oscillator 2 and the coherent oscillator 3
Is input to the frequency conversion means 4 and becomes a high-frequency pulse, which is radiated to the search space by the transmission antenna 1 at a timing controlled by the timing generation means 5 based on the phase information of the coherent oscillator 3. A reflected signal from a target located at a certain position in the search space is received by two receiving antennas 6a and 6b which are directly or once reflected on the ground or the sea surface, and which are arranged vertically to the ground. Two receiving antennas 6a
And 6b are input to sum signal generating means 7 for outputting the sum component and difference signal generating means 8 for outputting the difference component. The outputs of the sum signal generating means 7 and the difference signal generating means 8 are respectively output from the stabilized local oscillator 2 to the mixer 9a.
And 9b to convert it to an IF signal. Two mixers 9a and 9
The output of b is converted into a signal of an in-phase component by the phase detectors 10a and 10c with reference to the output of the coherent oscillator 3, and the phase detectors 10b and 10d by the π / 2 phase shifter 11 with reference to the output of the coherent oscillator 3. It is converted to a signal of orthogonal components. The outputs of the phase detectors 10a to 10d are input to A / D converters 12a to 12d,
It is converted and output. A / D conversion means 12a to 12d
Is input to the complex division means 13, and the result of performing complex division Δ / Σ between Σ of the complex number and Δ of the complex number is output.

Here, a method of obtaining the target elevation angle utilizing the property of the complex elevation trajectory focused on in the present invention will be described with reference to FIG. The output of the complex division means 13 is similar to the above-mentioned conventional example,
A complex elevation trajectory is drawn on a complex plane based on the width of the beam formed by the receiving antenna 6, the direction of the main beam, the height of the antenna, the frequency used, and the like. In particular, when the target is traveling at the same altitude at a long distance, the complex elevation trajectory due to the change of the elevation angle draws a circle as shown by 100a in FIG. The shape of this circle depends on the width of the beam formed by the receiving antenna 6, the direction of the main beam,
Although it differs depending on the height of the antenna, the frequency used, and the like, the center is a pure imaginary number and has a property of corresponding to the target elevation angle when there is no interference by the multipath reflected wave, and the present invention utilizes this property. Assuming that one point on this circle can be obtained by one observation when the target is moving at a constant altitude and a constant speed, a point on this circle as shown in FIG. Several points 101a to 101d are obtained. By using, for example, three points on the plurality of circles, the center 102 of the circle can be obtained. Now, four complex observations x ₁ + ji ₁ , x ₂ + ji ₂ , x
_{3 + jy 3, x 4 +} jy 4 is obtained, if the value of the real part is 0, the value y _c of the imaginary part of the circle center on the complex plane is obtained by the following equation, as described in the prior art There is no ambiguity.

[0052]

(Equation 7)

Next, the angle conversion means which is another important element will be described. The angle conversion means previously obtains a value of Δ / Σ according to the target elevation angle θ in the case where there is no interference by the multipath reflected wave in the form of the following equation (38). It may be stored in a table format. Δ / Σ = f (θ) (38) The elevation angle of the target can be obtained using the value of the center of the circle obtained by Expression (37) and the inverse function of Expression (38).

[0054]

(Equation 8)

In FIG. 1, for example, the first input value storage means 15 constituted by a sample-and-hold circuit stores observation values until four complex numbers which are the outputs of the complex division means 13 are input, and then simultaneously stores these four values. Output one. In the first circle center calculating means 16, the four observed values output from the first input value storing means 15 are put into equation (37), the center of the circle is obtained, and the value is output. The angle conversion means 17 refers to the relational expression of the expression (39) obtained in advance and obtains and outputs a target elevation angle from the above output. Compared with the fourth conventional example, the angle can be calculated strictly and the angle can be accurately obtained even at a long distance, so that the calculation is simple and the amplitude control is unnecessary.

Embodiment 2 FIG. In this embodiment, the center frequency of the circle is obtained by changing the oscillation frequency on the transmission side and equivalently obtaining different coordinate values on the complex plane. Thus, even when the target is at a low speed, the angle can be obtained. Hereinafter, another embodiment of the present invention will be described with reference to the drawings. FIG.
Is the configuration diagram, the new part in the figure is the first of 18
And a frequency variable stabilized local oscillator 19. Other components are the same as those shown in FIG. 1 of the first embodiment.

Next, the operation will be described. The present invention utilizes the fact that the circle on the complex plane drawn by the output value of the complex divider 13 is drawn not only when the distance changes due to the movement of the target, but also when the oscillation frequency is changed regardless of the movement of the target. . The first frequency control means 18 determines different frequencies by the number of inputs required for calculation by the first circle center value calculation means 16, and performs frequency variable stabilization so that the frequency variable stabilization local oscillator 19 oscillates. A control signal is output to the local oscillator 19 and the timing generator 5. The frequency variable stabilized local oscillator 19 oscillates a plurality of frequencies controlled by the first frequency control means 18.

For example, when the center of the circle is obtained from the four observation values by the equation (37) as in the first embodiment, the first frequency control means 18 controls the frequency-variable stabilized local oscillator 1
9 oscillates at _four different frequencies f ₁ , f ₂ , f ₃ and f ₄ . At each frequency, the complex division means 13 outputs the corresponding four division values, and obtains the target elevation angle even if the target does not move so much as in the first embodiment.

Embodiment 3 FIG. In the present embodiment, even when a set of a plurality of reception signals, that is, target position information becomes inaccurate due to noise or the like, an attempt is made to obtain a more accurate angle from the plurality of sets, that is, continuity of the position information. Multiple sets of angle calculations are required,
Although it takes time, the reliability is improved. Hereinafter, another embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a block diagram showing the configuration. In this figure, new parts are a second input value storage means 20, a second circle center calculation means 21, and a first input value selection means 22. Other components are the same as those shown in FIG. 1 of the first embodiment. An important element in the present embodiment is the second circle center calculating means 21. The second circle center calculation means 21 stores a plurality of sets of circle center values which are calculation results.

Next, the operation will be described. Example 1 above
When the same operation as described above is performed, the operation up to the output of the complex division means 13 is the same. The second input value storage means 20 stores the outputs of the complex division means 13 by a different number from the first input value storage means 15 and outputs them simultaneously. The second circle center calculation means 21 receives the output of the second input value storage means 20 and
The center of the circle on the complex plane is obtained and output by using means different from the circle center calculating means 16.

For example, when the target is moving at the same altitude at a constant speed as in the first embodiment, the first input value storage means 15 outputs the complex number output from the complex division means 13 at a certain time interval. After storing observation values until four are input, output four at the same time. The first circle center calculating means 16 applies the four observed values output from the first input value storing means 15 to the equation (37), finds the center of the circle, and outputs the value. On the other hand, in the second input value storage means 20, the complex number output from the complex division means 13 at a certain time interval is 16
After storing observation values until the number of observations is input, 16 are output at the same time. The second circle center calculating means 21 calculates the center of the circle from the 16 observation values output from the second input value storage means 20 using the least squares method and outputs the circle center. Next, the operation of the first input value selection means 22 will be described based on the flowchart of FIG. In ST1, four outputs of the first calculation means 16 (S1, S2, S3, S4) and one output of the second calculation means 21 (L1) are input. In ST2, S1, S2, S
3. The variance σ of S4 is determined. The magnitude of this variance σ is 16
It indicates the magnitude of the altitude change due to the movement of the target while obtaining the observation values. The value is large if the altitude change is large, and the value is small if the altitude change is small. In ST3, if σ is smaller than the predetermined value T, the process proceeds to ST4, and if it is larger, the process proceeds to ST5. In ST4, L1 is output, and in ST5
Then, S1, S2, S3, and S4 are sequentially output. As a result, a result with an accuracy corresponding to the movement of the target is obtained. The angle conversion means 17 calculates and outputs a target elevation angle from the input of the first input value selection means 22, as in the other embodiments.

Embodiment 4 FIG. This embodiment is a combination of the second and third embodiments. That is, a plurality of sets of oscillation frequencies are sequentially changed on the transmission side, and the result of each set is compared with the average of all sets. If the change is small, an average is obtained. If there is a change, the change of each set is output. Hereinafter, another embodiment of the present invention will be described with reference to the drawings. The new part in FIG.
Input value selection means. 18 frequency control means, 19
The frequency-variable stabilized local oscillator of the third embodiment is the same as that shown in FIG. 6 of the second embodiment, and the other components are the same as those of the third embodiment.
Is equivalent to that shown in FIG.

Next, the operation will be described. The twentieth input value selection means 23 refers to the number of inputs stored by the first input value storage means 15 and the second input value storage means 20, and outputs the larger number. The first frequency control means 18 receives the output of the twentieth input value selection means 23 and generates a timing with the frequency variable stabilized local oscillator 19 so that the frequency variable stabilized local oscillator 19 oscillates at the same number of different frequencies. A control signal is output to the means 5. The frequency variable stabilized local oscillator 19 oscillates a plurality of frequencies controlled by the first frequency control means 18. For example, when obtaining the center of a circle as in the third embodiment, the first input value
Second, since the second input value storage means 20 stores 16 input values, the second input value selection means 23 outputs "16". The first frequency control means 18 controls the timing of the timing generation means 5 and the 16 different frequencies f1, f
2,... F15, f16, frequency-variable stabilized local oscillator 1
9 to output a control signal. The complex divider 13 outputs one at each frequency, and outputs the target elevation angle in the same manner as in the third embodiment.

Embodiment 5 FIG. This embodiment utilizes the fact that the speeds of a plurality of targets are different, prepares and separates a plurality of coherent integrating means, and obtains angle information for each of the targets. Hereinafter, another embodiment of the present invention will be described with reference to the drawings. In FIG. 10 , the new parts are the thirteenth input value storage means 24a to the nth input storage means 24b, and the first coherent integration means 25a to the nth coherent integration means 25b. Further, the complex operation means is also from the first complex operation means of 13a to the nth complex operation means of 13b, and the first input value storage means is also from the first input value storage means of 15a to the nth input value of 15b. In the storage means,
The circle center calculating means is also 1 from the first circle center calculating means of 16a.
The angle conversion means is also 17a in the n-th circle center calculation means of 6b.
And n sets of angle detectors from the first angle converter to the n-th angle converter 17b. Other components are the same as those shown in FIG. 5 of the third embodiment.

Next, the operation will be described. Example 3 above
When the same operation is performed, the operation up to the output of the A / D converter 12 is the same. Third input value storage means 24a, 24
In b, a plurality of outputs of the A / D conversion means 12 are stored for each group and then output simultaneously. For example, A / D conversion means 12a to 12
The observation values are stored until 64 outputs of 12d are input, and then 64 outputs are simultaneously output. Coherent integration means 25
a, 25b, the thirteenth and n3th input value storage means 24a,
Receiving the output of 24b, it outputs the result of performing coherent integration for performing integration by discriminating for each target Doppler frequency component using DFT or FFT. This allows
Multiple targets with different speeds can be separated even if they are close in space. Outputs of the coherent integration means 25a and 25b are respectively output to the complex division means 13a and
13b, and the elevation angle is output for each target having a different Doppler frequency.

In the above embodiment, the number of the circle center calculating means after the velocity separation is one for each of the first to n-th sets. However, as described in the third and fourth embodiments, or in the following sixth embodiment, like,
The number may be two for each of the first to n-th sets.

Embodiment 6 FIG. This embodiment addresses multiple targets using the multiple coherent integrations of Embodiment 5,
This is a combination of changing the transmission frequency of the second embodiment and using a plurality of circle center calculation means of the third and fourth embodiments. Hereinafter, another embodiment of the present invention will be described with reference to the drawings. The new part in FIG. 11 is 26 second frequency control means. 19 frequency-variable stabilized local oscillators,
The twenty-third twentieth input value selecting means is the same as that shown in FIG. 9 of the fourth embodiment, and the other components are the same as those shown in FIG. 9 of the fourth embodiment and FIG. 10 of the fifth embodiment. It is.
FIG. 12 shows the relationship between the number of observations and the frequency used.

Next, the operation will be described. The twentieth input value selection means 23 refers to the number of inputs stored by the first input value storage means 15 and the second input value storage means 20, and outputs the larger number. The second frequency control means 26 inputs the output M of the second input value selection means 23 and the integration number N of the coherent integration means 25. As shown in FIG. Are frequency f2 and (M-1) N +
1 to MN have a frequency fM, and the frequency-variable stabilized local oscillator 1
9 and a control signal to the timing generation means 5. The frequency-variable stabilized local oscillator 19 is connected to the second frequency control means 2.
A plurality of frequencies controlled by 6 are oscillated.

For example, when the same operation as in the fifth embodiment is performed, first, the frequency variable stabilized local oscillator 19 oscillates at the frequency f1 by the second frequency control means 26,
3, n3 input value storage means 24a and 24b store observation values until 64 outputs of the A / D conversion means 12 are input, and then output 64 output values simultaneously. Coherent integration means 2
In 5a and 25b, the thirteenth and n3th input value storage means 24
a, and outputs the result of performing coherent integration in response to the outputs of 24b. Coherent integration means 25a, 25b
Are input to the first and n-th complex division means 13a and 13b as in the fifth embodiment. An eleventh input value storage means 15a, an eleventh circle center calculation means 16a,
Input value storage means 20a, twelfth circle center calculation means 21
a, the first input value selection means 22a and the first angle conversion means 17a, and the angle conversion operation are described in the third and fourth embodiments.
Performs the same operation as described above. Thereafter, the second frequency control means 26 controls the frequency-variable stabilized local oscillator 19 to 1
Oscillation is performed at five different frequencies f2 to f16, and the same operation is repeated, and an elevation angle is output for each target having a different Doppler frequency.

In the above-described embodiment, two circle center calculating means after the coherent integration are provided for each of the first to n-th sets. However, as shown in the fifth embodiment, one may be provided for each set. .

Embodiment 7 FIG. This embodiment shows an example in which a target speed is detected and the timing is controlled so as to be a reception interval suitable for the target speed, and a sample interval for angle detection is determined. That is, a loop system that detects the target speed and controls the timing on the transmission side is configured. Hereinafter, another embodiment of the present invention will be described with reference to the drawings. In FIG. 13 , new parts are a target speed detecting means 27 and a timing control means 28. The other components are the same as those shown in FIG. 11 of the sixth embodiment.

Next, the operation will be described. Example 6 above
When the same operation as described above is performed, the coherent integration means 2
A signal corresponding to the magnitude of each Doppler frequency component appears at the output of No. 5. The target speed detecting means 27 receives these and outputs, for example, the result obtained by converting the Doppler frequency having the maximum magnitude into the target speed by using the following equation (40) as the target Doppler frequency.

V = fd · λ / 2 (40) Here, v: speed fd: Doppler frequency λ: wavelength used The timing control unit 28 inputs the target speed which is the output of the target speed detection unit 27, The timing generation unit 5 is controlled by determining the observation time interval according to the speed.

In this embodiment, an example in which a plurality of sets of coherent integration means are used and applied to a plurality of targets has been described. However, as for the timing control, only one coherent integrating means may be used, and it is sufficient if the speed can be detected.

Embodiment 8 FIG. In this embodiment, instead of waiting for timing to detect a target speed, sampling is performed at a frequency interval suitable for the target speed by changing the transmission frequency of the transmission side. Hereinafter, another embodiment of the present invention will be described with reference to the drawings. In FIG. 14, the new parts are 29 frequency setting means and 30 third frequency control means. Further, the 19 frequency-variable stabilized local oscillator is the same as that shown in FIG. 11 of the sixth embodiment, and the other components are the same as those shown in FIG. 13 of the seventh embodiment.

Next, the operation will be described. First, the output of the coherent integrator 25 is applied to the output of the coherent integrator 25 by the signal generated by the frequency-variable stabilized local oscillator 19 and the coherent oscillator 3 controlled to oscillate at a certain frequency f1 by the third frequency controller 30. A signal corresponding to the size appears. The target speed detecting means 27 receives these, and outputs a result obtained by converting the Doppler frequency component having the largest magnitude into a target speed from the equation (40), for example, as a target Doppler frequency. The frequency setting means 29 inputs the target speed which is the output of the target speed detecting means 27,
The used frequency interval df according to the speed is determined and input to the third frequency control means 30. The third frequency control means 30 is additionally provided with the eleventh and n1th input value storage means 15
a, 15b and twelfth, n2 input value storage means 20a, 2
Reference is made to the number of inputs stored at 0b, the twentieth input value selection means output 23 which outputs the larger number, and the number of inputs stored at the thirteenth input value storage means 24a. Then, in the subsequent observation, the frequency variable stabilized local oscillator 19 is controlled so as to oscillate at the frequency interval df with the same relationship between the number of observations and the frequency as in FIG. 12 of the sixth embodiment.

Embodiment 9 FIG. In this embodiment, an angle detection device is provided on different measurement surfaces, for example, a horizontal surface and a vertical surface, and the angle is three-dimensionally obtained by combining the angle detection devices. The configuration is such that components having the same function are installed so that the receiving direction surface of the receiving antenna is horizontal and vertical. Hereinafter, another embodiment of the present invention will be described with reference to the drawings. In FIG. 15, the components are the same as those shown in FIG. 1 of the first embodiment.

Next, the operation will be described. Example 1 above
In the case where the same operation as that of the first embodiment is performed, the operation up to the output of the transmitting antenna 1 in FIG. A reflected signal from a target existing at a certain position in the search space is received by the receiving antennas 6a and 6b which are arranged directly or once after being reflected on the ground or the sea surface and arranged vertically to the ground. Similarly, the reflected signal from the target is reflected directly or once on a slope of a mountain or a structure having a height higher than the receiving antennas 6c and 6d, and then reflected by the receiving antenna 6c arranged horizontally with the ground. 6d. A plurality of outputs from the two receiving antennas 6a and 6b are obtained at a certain time interval as in the first embodiment, and the angle conversion means 17a outputs the elevation angle of the moving target. Similarly, a plurality of outputs from the two receiving antennas 6c and 6d are obtained at a certain time interval as in the first embodiment, and the angle conversion means 17b outputs the azimuth of the moving target.

Embodiment 10 FIG. This embodiment is a combination of Embodiment 2 and Embodiment 9. Hereinafter, another embodiment of the present invention will be described with reference to the drawings. In FIG. 16, the components are the same as those shown in FIG. 6 of the second embodiment and FIG. 15 of the ninth embodiment.

Next, the operation will be described. Example 2 above
In the case where the same operation as that described above is performed, the operation up to the output of the transmitting antenna 1 in FIG. A reflected signal from a target existing at a certain position in the search space is received by the receiving antennas 6a and 6b which are arranged directly or once after being reflected on the ground or the sea surface and arranged vertically to the ground. Similarly, the reflected signal from the target is reflected directly or once on a slope of a mountain or a structure having a height higher than the receiving antennas 6c and 6d, and then reflected by the receiving antenna 6c arranged horizontally with the ground. 6d. A plurality of outputs of the two receiving antennas 6a and 6b are obtained by changing the frequencies used by the first frequency control means 18 and the frequency-variable stabilized local oscillator 19 in the same manner as in the second embodiment. 17a outputs the elevation angle of the target. Similarly, the outputs of the two receiving antennas 6c and 6d are obtained by changing the frequencies used by the first frequency control means 18 and the frequency-variable stabilized local oscillator 19 in the same manner as in the second embodiment. The angle conversion means 17b outputs a target azimuth angle.

Embodiment 11 FIG. The angle of the received signal after the A / D conversion can be obtained by a general-purpose computer.
In the configuration, for example, in FIG. 1, the outputs of the A / D converters 12a to 12d of the respective complex components are connected to a common computer. FIG. 17 is a flowchart showing an example of the calculation method of the computer in that case. The operation of this angle detection method will be described. As a step corresponding to the angle conversion, an inverse function for obtaining the angle θ from the center value of the circle is stored in advance.
That is, in step ST1, y = f with respect to the center y of the circle.
(Θ) is calculated and stored. If there is a received signal, it is reset to take in data in step ST2, and in step ST14, the first data is taken from the four A / D outputs to perform a complex operation of Δ / Σ. For example, if the center of the circle is determined at three points, n = 3, and the complex operation is continued until i becomes 3 in step ST15. When n becomes 3, x ₁ , y _1, etc. are obtained in step ST 16, and step ST 17
Calculate y _c based on equation (37). Finally, based on the calculation in step 11 in step ST18, or outputs the angle theta _c refers to the storage to have a table.

Embodiment 12 FIG. A radar device using the angle detection device according to the present invention will be described. FIG. 18 is a configuration diagram of a radar apparatus according to the present invention. In the figure, 1 is a transmitting antenna,
6a and 6b are receiving antennas, 31 is a display device, and each element between them is each element of the angle detection device shown in FIG. The operation of this radar device is as follows. The transmission signal radiated from the transmission antenna 1 is reflected and returned to the target and received from the reception antennas 6a and 6b. The angle signal detected by the angle detection device enters the display device 31 and appears on the display screen. Instead of giving it to the display screen, it may be given to another control device.

[0083]

The angle detecting device, the angle detecting method and the radar device according to the present invention are configured as described above, and have the following effects.

Since the apparatus includes complex division means, circle center calculation means and angle conversion means, an accurate target angle can be obtained with a small number of calculations.

A variable frequency oscillator is provided with a transmitting means, a complex division means of a received wave, a circle center calculating means and an angle converting means, so that an accurate target angle can be obtained with a small number of calculations.

A complex division means, first and second circle center calculation means and angle conversion means are provided, and a more accurate target angle can be obtained based on signal continuity with a small number of calculations.

The variable frequency oscillator includes transmitting means, receiving wave complex dividing means, first and second circle center calculating means, and angle converting means. The target angle is obtained.

A plurality of coherent integration means, complex division means, circle center calculation means and angle conversion means are provided, and the speed of each of the plurality of targets is detected so that an accurate target angle can be obtained with a small number of calculations for each target. .

A plurality of coherent integrating means, complex dividing means, first and second circle center calculating means, and angle converting means are provided to detect respective speeds of a plurality of targets and to perform signal continuity with less calculation. , A more accurate target angle is obtained.

The apparatus is provided with speed detecting means, timing controlling means, complex dividing means, circle center calculating means, and angle converting means. Detecting each speed of a plurality of targets, an appropriate receiving timing can be obtained, and each target has a small receiving timing. An accurate target angle can be obtained by calculation.

The apparatus includes a speed detecting means, a frequency setting means, a complex dividing means, a circle center calculating means and an angle converting means, and detects respective speeds of a plurality of targets to obtain an appropriate transmitting side oscillation frequency. , An accurate target angle can be obtained with a small number of calculations for each target.

A plurality of angle detecting devices are provided, and a three-dimensional angle with respect to the target can be obtained by combining a plurality of planes.

A plurality of angle detectors are provided, and a three-dimensional angle with respect to a target obtained by combining a plurality of planes by changing the oscillation frequency on the transmission side can be obtained.

Based on the calculation step, the center value of the complex circle is obtained, and an accurate target angle can be obtained by the calculation.

The radar device is provided with complex division means, circle center calculation means and angle conversion means, and can display an accurate target angle with a small number of calculations.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an angle information detection device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an output of a complex divider according to the first embodiment.

FIG. 3 is a diagram illustrating an example of a numerical simulation in the first embodiment.

FIG. 4 is a modeling diagram of a relationship between a target and an angle detection device in the first embodiment.

FIG. 5 is a diagram showing a result of a numerical simulation and a result of a conventional method.

FIG. 6 is a configuration diagram of an angle information detection device according to a second embodiment of the present invention.

FIG. 7 is a configuration diagram of an angle information detection device according to a third embodiment of the present invention.

FIG. 8 is a flowchart illustrating an operation of a first input value selection unit according to the third embodiment.

FIG. 9 is a configuration diagram of an angle information detection device according to a fourth embodiment of the present invention.

FIG. 10 is a configuration diagram of an angle information detection device according to a fifth embodiment of the present invention.

FIG. 11 is a configuration diagram of an angle information detection device according to a sixth embodiment of the present invention.

FIG. 12 is a diagram illustrating a relationship between the number of observations and a used frequency according to a sixth embodiment.

FIG. 13 is a configuration diagram of an angle information detection device according to a seventh embodiment of the present invention.

FIG. 14 is a configuration diagram of an angle information detection device according to an eighth embodiment of the present invention.

FIG. 15 is a configuration diagram of an angle information detection device according to a ninth embodiment of the present invention.

FIG. 16 is a configuration diagram of an angle information detection device according to a tenth embodiment of the present invention.

FIG. 17 is an operation flowchart of the method according to the eleventh embodiment.

FIG. 18 is a configuration diagram of a radar apparatus according to a twelfth embodiment.

FIG. 19 is a diagram showing the relationship between S ₁ and θ.

FIG. 20 is a basic configuration diagram of a conventional angle information detection device.

FIG. 21 is a diagram illustrating two reception antenna beams and their sum and difference components with respect to a target elevation angle of the angle information detection device.

FIG. 22 is a diagram showing an output of a complex division unit of the conventional angle information detecting device.

FIG. 23 is a diagram showing a model of a conventional reflected wave.

FIG. 24 is a diagram showing a model of a conventional reflected wave.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transmission antenna 2 Stabilized local oscillator 3 Coherent oscillator 4 Frequency conversion means 5 Timing generation means 6a, 6b Receiving antenna 7 Sum signal generation means 8 Difference signal generation means 9 Mixer 10 Phase detection means 11 π / 2 phase shift means 12a, 12b , 12c, 12d A / D conversion means 13 complex division means 13a first complex division means 13b nth complex division means (second complex division means) 14 complex angle conversion means 15 first input value storage means 15a 11th input value storage means (first input value storage means) 15b n1th input value storage means (second input value storage means) 16 first circle center calculation means 16a 11th circle center calculation means (first No. 1 circle center calculation means) 16b n1st circle center calculation means (second circle center calculation means) 17 Angle conversion means 17a First angle conversion means 17 N-th angle conversion means 18 first frequency control means 19 frequency-variable stabilized local oscillator 20a twelfth input value storage means 20b n-th input value storage means 21a twelfth circle center calculation means 21b n2th circle center Arithmetic means 22, 22a First input value selection means 22b Nth input value selection means 23 Twentieth input value selection means 24a Thirteenth input value storage means 24b Nth input value storage means 25a First coherent integration Means 25b Nth coherent integration means 26 Second frequency control means 27 Target speed detection means 28 Timing control means 29 Frequency setting means 30 Third frequency control means 31 Display device 100a Complex elevation angle trajectories 101a, 101b, 101c, 101d Observation Value 102 Center of circle 103a, 103b Antenna beam 104 Sum component signal 05 difference component signal 108 of monopulse for the arrival angle of a single wave source Δ
/ C 109 Range where Δ / Σ can be linearly approximated 110c Direct wave path 111c Reflected wave path 112c Reflecting surface 113c Main beam direction 114c Direct wave arrival angle 115c Reflected wave arrival angle 116c Antenna height 117c Target altitude 118c Reference Line 119c Antenna 120b Target ST11 Step of calculating and storing the relationship between the sum and difference division value and the angle ST14 Step of obtaining XY coordinate values from the sum and difference division result ST15 Step of repeating required number of operations ST17 Step of obtaining center of circle from XY coordinate values ST18 Step for calculating angle from circle center value to target

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tomomasa Kondo 5-1-1, Ofuna, Kamakura City Mitsubishi Electric Corporation Electronic Systems Laboratory (56) References JP-A-5-196725 (JP, A) JP-A-5-196725 JP-A-60-46477 (JP, A) JP-A-62-108175 (JP, A) JP-A-1-233386 (JP, A) JP-A-2-55981 (JP, A) JP-A-63-180880 (JP) (A) Special table Hei 6-500388 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01S ⁷ /00-7/42 G01S 13/00-13/95

Claims (12)

(57) [Claims] A sum signal generating means for generating a sum component of the received signal; a difference signal generating means for generating a difference component of the received signal; mixing the sum and difference signals with a local oscillation signal to generate a coherent oscillation signal; A complex division means for performing phase division by performing phase detection to obtain each quadrature phase component, and performing a complex division from the obtained sum signal and difference signal of the complex number, and suppose that the result of the complex division substantially draws a circle on a complex plane,
Assuming that a plurality of results of the complex division corresponding to a plurality of received signals are on the circle, circle center calculating means for calculating a center value of the circle; and calculating an angle from a center value of the circle output from the circle center calculating means. An angle detection device comprising an angle conversion unit. 2. A transmission means having a variable frequency oscillator for transmitting radio waves to a target at a different transmission frequency, and a sum signal generation for generating a sum component of a reception signal which is a reflected wave of a transmission signal output from the transmission means. Means, a difference signal generating means for generating a difference component of the received signal, and mixing the sum and difference signals with a local oscillation signal, and performing phase detection with a coherent oscillation signal to obtain each quadrature phase component. Complex division means for performing complex division from a sum signal and a difference signal of complex numbers, and a result of the complex division described above is almost a circle on a complex plane,
Assuming that a plurality of complex division results corresponding to a plurality of reception signals corresponding to different transmission frequencies are on the circle, a circle center calculating means for calculating a center value of the circle; and a center of the circle output from the circle center calculating means. An angle conversion device for obtaining an angle from a value. 3. The circle center calculating means is a first circle center calculating means, and a second circle center calculating means for obtaining a circle center on a complex plane based on a complex division result by reception signals at different times. And input value selection means for comparing the output of the first circle center calculation means and the output of the second circle center calculation means to select an output from which the continuity of change from the previous observed value is obtained, 2. The angle detecting device according to claim 1, wherein an output of said input value selecting means is provided to an angle converting means. 4. The method according to claim 1, wherein the circle center calculation means is a first circle center calculation means, and a complex division result by a reception signal corresponding to a transmission signal having an oscillation frequency different from a transmission signal for the first circle center calculation means. A second circle center calculating means for finding a center of a circle on a complex plane, and comparing the output of the first circle center calculating means with the output of the second circle center calculating means based on 3. An angle detecting device according to claim 2, further comprising: input value selecting means for selecting an output from which continuity of change is obtained, wherein an output of said input value selecting means is supplied to an angle converting means. 5. The method of claim 1, further comprising detecting the sum and difference of the received signals with a coherent oscillating signal to obtain respective quadrature components, and further coherently integrating the received signals to obtain a sum signal of a plurality of complex numbers. First to n-th coherent integration means for obtaining a difference signal; and complex division means, corresponding to the first to n-th coherent integration means outputs, sum signals of complex numbers obtained by the respective integration means. First to n-th complex divisions from the difference signal
Each of the complex division means of the above, the circle center calculation means, assuming that the result of each of the complex divisions draws a substantially circle on a complex plane, and that a plurality of the results of the complex division corresponding to a plurality of received signals are on the circle Corresponding first to n-th circle center calculating means for calculating the center value of the circle, and the angle calculating means corresponding to calculating the angle from the center value of the circle output from each of the circle center calculating means. 3. The angle detection device according to claim 1, further comprising: n angle conversion means. 6. A phase detection of the sum and difference signals of the received signals with a coherent oscillation signal to obtain respective quadrature phase components, and coherent integration for a plurality of received signals to obtain a sum signal of a plurality of complex numbers. First to n-th coherent integration means for obtaining a difference signal; and complex division means, corresponding to the first to n-th coherent integration means outputs, sum signals of complex numbers obtained by the respective integration means. First to n-th complex divisions from the difference signal
Each of the complex division means of the above, the circle center calculation means, assuming that the result of each of the complex divisions draws a substantially circle on a complex plane, and that a plurality of the results of the complex division corresponding to a plurality of received signals are on the circle Corresponding eleventh to n1-th circle center calculating means for calculating the center value of the circle, and a twelfth for obtaining the center of the circle on the complex plane based on the same complex division result by the received signals having different time or frequency in time. To the n2th circle center calculation means, and the input selection means compares the outputs of the eleventh and twelfth circle center calculation means to select an output from which the continuity of change from the previous observed value is obtained. From the first input value selection means to the n-th input selection means for comparing the output of the n-th and the n-th circle center calculation means and selecting the same through the same configuration operation, 1 to n-th input 3. The angle detecting device according to claim 1, further comprising first to n-th angle converting means for obtaining an angle from a center value of the circle corresponding to the force selecting means. 7. A coherent method for obtaining a quadrature phase component by phase-detecting each of the sum and difference signals of the received signals with a coherent oscillation signal and performing coherent integration corresponding to the received signals to obtain a complex sum signal and a difference signal. Integrating means, target speed detecting means for obtaining a target speed from the output of the coherent integrating means, and timing control means for determining an observation time interval from the target speed calculated by the target speed detecting means. 2. The angle detection device according to claim 1, wherein observation is performed. 8. A coherent method for obtaining a quadrature phase component by phase-detecting a sum signal and a difference signal of a received signal with a coherent oscillation signal and performing coherent integration corresponding to the received signal to obtain a complex sum signal and a difference signal. Integrating means, target speed detecting means for obtaining a target speed from the output of the coherent integrating means, and frequency setting means for determining the frequency interval of the transmission frequency from the target speed calculated by the target speed detecting means,
3. The angle detecting device according to claim 2, wherein the transmission frequency of the transmission signal is changed at the set frequency interval, and the observation is performed. 9. Further, a plurality of sets of sum signal generation means, difference signal generation means, complex division means, circle center calculation means and angle conversion means are provided, and angles in different directions are obtained. The angle detection device according to claim 1. 10. A system according to claim 1, further comprising a plurality of sets of transmitting means, sum signal generating means, difference signal generating means, complex dividing means, circle center calculating means and angle converting means, and obtaining angles in different directions. 3. The angle detecting device according to claim 2, wherein 11. Assuming that there is no multipath reflected wave in the received signal, calculating and storing a difference signal of the received signal and a divided value of a sum signal of the received signal as a function form with respect to the angle of arrival; Obtaining a difference signal and a sum signal, and further performing complex division from the obtained difference / sum signal; repeating the operation of performing complex division of the actual received signal to obtain an imaginary value and a real value a plurality of times; Determining the center of a circle passing through each point from the imaginary and real values of the result of the complex division, and determining the angle of arrival by referring to the function form from the obtained value of the center of the circle. Angle detection method. 12. A transmitting antenna for emitting a radar transmitting radio wave, a plurality of receiving antennas for receiving a receiving wave corresponding to the transmitting radio wave, a sum signal generating means for generating a sum component of the received signal, A difference signal generating means for generating components; mixing the sum and difference signals with a local oscillation signal; performing phase detection with a coherent oscillation signal to obtain each quadrature phase component; and obtaining a sum signal and a difference signal of the obtained complex numbers. And complex division means for performing complex division from the above, assuming that the result of the complex division draws a circle on a complex plane, and from the results of the plurality of complex divisions corresponding to a plurality of reception signals corresponding to different transmission frequencies, the center of the circle A radar apparatus comprising: first calculation means for obtaining a value; angle conversion means for obtaining an angle from a center value of a circle output from the first calculation means; and display means for displaying the obtained angle.