JP3946692B2 - Radio wave detector - Google Patents

Description

  The present invention relates to a radio wave detection device that receives radio waves emitted from a target and measures the direction of the radiation source.

  In order to measure not only the arrival direction of the radio wave but also the arrival angle of the radio wave when measuring the direction of the radio wave radiated by the target, the conventional radio wave detection device has an azimuth angle and an elevation angle. A controllable linear beam antenna is installed, and the movable control unit separately controls the azimuth angle and elevation angle of the linear beam antenna so that incoming radio waves can be spatially scanned in two dimensions (for example, patents). Reference 1).

JP 2002-267742 A (paragraph numbers [0011] to [0015], FIG. 1)

  Since the conventional radio wave detection device is configured as described above, if the movable control unit controls the azimuth and elevation angles of the linear beam antenna and sequentially scans the space, the direction of radio waves coming from the desired coverage However, the larger the desired coverage, the longer the space scanning time and the lower the probability of detecting a single incoming radio wave.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a radio wave detection device capable of reliably detecting a single incoming radio wave even when a desired coverage is large. .

  The radio wave detection device according to the present invention includes a first azimuth estimating means for comparing the amplitudes of radio waves received by a plurality of antennas constituting the first antenna group, and estimating the arrival direction of the radio waves, A second azimuth estimating means for comparing the phase differences of the radio waves received by the plurality of antennas constituting the antenna group and estimating the arrival direction of the radio waves, and estimated by the first azimuth estimating means An azimuth difference between the arrival azimuth and the arrival azimuth estimated by the second azimuth estimation means is obtained, and the arrival elevation angle of the radio wave is calculated from the azimuth difference.

  According to the present invention, the first direction estimating means for comparing the amplitudes of radio waves received by a plurality of antennas constituting the first antenna group and estimating the arrival direction of the radio waves, and the second antenna group A second azimuth estimating means for estimating the arrival direction of the radio waves by comparing the phase differences of the radio waves received by the plurality of antennas constituting the arrival direction estimated by the first azimuth estimation means; Since the azimuth difference of the arrival azimuth estimated by the second azimuth estimation means is obtained, and the arrival elevation angle of the radio wave is calculated from the azimuth difference, even if the desired coverage is large, a single incoming radio wave can be obtained. There is an effect that can be detected reliably.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a radio wave detection apparatus according to Embodiment 1 of the present invention. In the figure, an amplitude comparison system antenna 1 which is a first antenna group is composed of a plurality of element antennas arranged radially. ing.
The detection circuit 2 detects RF radio waves received by a plurality of element antennas constituting the amplitude comparison method antenna 1, converts the detection signal into a video signal, and outputs the video signal. The azimuth estimation processing unit 3 compares the signal level (corresponding to the amplitude of the RF radio wave received by the element antenna) of each element antenna output from the detection circuit 2 to determine the radio wave emitted by the target. Estimate the direction of arrival.
The detection circuit 2 and the direction estimation processing unit 3 constitute a first direction estimation unit.

The timing signal generation unit 4 outputs a timing signal to the phase difference calculation processing unit 7 when the signal level of the video signal output from the detection circuit 2 becomes higher than the reference level.
The phase difference detection type antenna 5 which is the second antenna group is composed of a plurality of element antennas arranged in a straight line (array).
The receiving unit 6 performs a Fourier transform on the RF radio waves received by a plurality of element antennas constituting the phase difference detection antenna 5 and outputs a frequency signal. When the phase difference calculation processing unit 7 receives the timing signal from the timing signal generation unit 4, the phase difference calculation processing unit 7 obtains the phase of the RF radio wave received by each element antenna from the frequency signal output from the reception unit 6, and calculates the phase difference of each RF radio wave. calculate. The direction estimation processing unit 8 estimates the arrival direction of the radio wave radiated from the target from the phase difference calculated by the phase difference calculation processing unit 7.
The receiving unit 6, the phase difference calculation processing unit 7 and the azimuth estimation processing unit 8 constitute a second azimuth estimating unit.

The elevation angle calculation processing unit 9 obtains an azimuth difference between the arrival azimuth estimated by the azimuth estimation processing unit 3 and the arrival azimuth estimated by the azimuth estimation processing unit 8, and the arrival elevation angle of the radio wave radiated by the target is calculated from the azimuth difference. An elevation angle calculating means for calculating is configured.
The azimuth determination processing unit 10 estimates the azimuth estimation processing unit 3 when the arrival elevation angle calculated by the elevation angle calculation processing unit 9 is larger than a predetermined threshold among the arrival azimuths estimated by the azimuth estimation processing units 3 and 8. The selected arrival direction is selected and output, and when the arrival elevation angle calculated by the elevation angle calculation processing unit 9 is smaller than a predetermined threshold, the arrival direction estimated by the direction estimation processing unit 8 is selected and output. Means.

  The target radio wave specification detection unit 11 detects the specifications of the target radio wave such as frequency and pulse repetition period from the frequency signal and RF radio wave output from the reception unit 6. The target information management unit 12 manages the elevation angle calculated by the elevation angle calculation processing unit 9, the azimuth angle selected by the azimuth determination processing unit 10, and the specifications of the target radio wave detected by the target radio wave specification detection unit 11.

Next, the operation will be described.
2 and 3 are explanatory views showing the principle of the direction finding process by the amplitude comparison method.
As shown in FIG. 2, the amplitude comparison antenna 1 is composed of a plurality of element antennas arranged radially, and is configured such that the beams of adjacent element antennas partially overlap each other. That is, the element beam is arranged so as to cover a desired radio wave coverage with the whole antenna 1 for amplitude comparison method.

When a plurality of element antennas constituting the amplitude comparison system antenna 1 receive an RF radio wave radiated from a target, the detection circuit 2 detects the RF radio wave, converts the detection signal into a video signal, and outputs the video signal.
The azimuth estimation processing unit 3 compares the signal level of the video signal related to each element antenna output from the detection circuit 2 (corresponding to the amplitude of the RF radio wave received by the element antenna), and the radio wave radiated from the target Estimate the direction of arrival.

Specifically, the video signal having the highest signal level is detected from the plurality of video signals, and the directivity direction of the element antenna corresponding to the video signal is estimated as the arrival direction of the radio wave.
Alternatively, the video signal having the highest signal level and the video signal having the second highest signal level among the plurality of video signals are detected, and the arrival direction of the radio wave is determined according to the ratio of the signal levels of the two video signals. presume.
For example, if the signal level of the video signal with the highest signal level is “3”, and the signal level of the video signal with the second highest signal level is “1”, the element antenna corresponding to the video signal with the highest signal level. And the directivity direction between the two element antennas (intermediate between the directivity direction of the element antenna corresponding to the video signal having the highest signal level and the directivity direction of the element antenna corresponding to the video signal having the second highest signal level) ) Is estimated as the direction of arrival of radio waves.

  In this way, in the method of estimating the direction of the incoming radio wave from the received radio wave of the amplitude comparison antenna 1 in which a plurality of element antennas are arranged radially, as shown in FIG. 3, the arrival elevation angle of the radio wave is not affected. The estimated direction coincides with the arrival direction of the radio wave.

4 and 5 are explanatory diagrams showing the principle of the direction finding process by the phase difference method.
As shown in FIG. 4, the phase detection method antenna 5 is composed of a plurality of element antennas arranged linearly in the same horizontal plane, and a plurality of element antennas constituting the phase difference detection method antenna 5. When the same incoming radio wave is received, a phase difference (path difference) is generated between the plurality of element antennas according to the arrival direction, so that the arrival direction can be calculated from the phase difference.

When the plurality of element antennas constituting the phase difference detection antenna 5 receive the RF radio wave radiated from the target, the receiving unit 6 performs a Fourier transform on the RF radio wave and outputs a frequency signal.
When receiving the timing signal from the timing signal generation unit 4, the phase difference calculation processing unit 7 obtains the phase of the RF radio wave received by each element antenna from the frequency signal output from the reception unit 6, and the phase difference of each RF radio wave Is calculated.
Here, the timing signal generator 4 synchronizes the azimuth estimation processing unit 3 and the azimuth estimation processing unit 8, that is, the radio wave that the azimuth estimation processing unit 3 estimates the azimuth and the azimuth estimation processing unit 8 determines the azimuth. In order to make the radio waves to be estimated the same, when the signal level of the video signal output from the detection circuit 2 becomes higher than the reference level, a timing signal is output to the phase difference calculation processing unit 7. Usually, the radio wave radiated from the target is a pulse-like signal. Therefore, if the timing at which the signal level of the video signal is greater than the reference level is detected, the arrival of the radio wave can be detected.
When the phase difference calculation processing unit 7 calculates the phase difference of each RF radio wave, the direction estimation processing unit 8 estimates the arrival direction of the radio wave emitted by the target from the phase difference. Since the method of estimating the arrival direction of radio waves from the phase difference of each RF radio wave is a known method, description thereof is omitted.

Thus, in the method of estimating the direction of the incoming radio wave from the received radio wave of the phase difference detection antenna 5 in which a plurality of element antennas are arranged in a straight line, as shown in FIG. ), The estimated azimuth coincides with the arrival azimuth of the radio wave without being influenced by the arrival angle of the radio wave, similarly to the above-described amplitude comparison method.
However, since the directions having the same phase difference (path difference) have the same estimated value (the estimated values of radio waves arriving from the direction of the equiphase difference line are the same), they are estimated as the same arrival direction. For this reason, when the elevation angle is not 0 degree, the estimation error increases as the elevation angle increases.
Therefore, as the elevation angle increases, the difference from the estimated direction value in the direction finding process by the amplitude comparison method of FIG. 3 also increases. An orientation difference that occurs in principle in such a phased array antenna (phase difference detection type antenna 5) is generally referred to as a coning error.

Here, FIG. 6 shows a coordinate system when an antenna located at the origin receives a radio wave radiated from a target T located at coordinates (γ _T , φ _T , θ _T ), and the amplitude shown in FIG. The relationship of the formula (1) is established between the estimated direction φ _T1 based on the comparison method and the actual arrival direction φ _T , and the relationship between the estimated direction φ _T2 based on the phase difference method and the actual arrival direction φ _T shown in FIG. Holds the relationship of equation (2).
φ _T1 = φ _T (1)
φ _T2 = sin ⁻¹ [(sin θ _T · sin φ _T ) / sin 90 °] (2)
Therefore, the coning error Δφ _T is as follows.
Δφ _T = φ _T2 −φ _T1 (3)

FIG. 7 is an explanatory diagram showing the relationship between the coning error and the elevation angle, in which the estimated equi-azimuth line by the amplitude comparison method is indicated by a dotted line, and the estimated iso-azimuth line by the phase difference method is indicated by a solid line.
For radio waves arriving from the elevation angle / azimuth on this isoazimuth line, the angle at which each isoazimuth line and the axis of elevation angle 0 degree intersect is calculated as the estimated orientation.
Target A and target B indicate targets that arrive at the same azimuth from different elevation angles. However, this target is different between an azimuth estimated by the amplitude comparison method and an azimuth estimated by the phase difference search method. The target A having a larger elevation angle has a larger difference than the target B.

As described above, when the azimuth estimation processing unit 3 estimates the arrival azimuth φ _T1 and the azimuth estimation processing unit 8 estimates the arrival azimuth φ _{T2, the} elevation angle calculation processing unit 9 calculates the arrival azimuth φ _T1 and the arrival azimuth φ _{T2 as described above.} A coning error Δφ _T which is an azimuth difference between arrival directions is obtained, and the arrival elevation angle θ _{T of the} radio wave radiated from the target T is calculated from the coning error Δφ _T by calculating back the equation (3).

When the elevation angle calculation processing unit 9 calculates the arrival angle θ _{T of the} radio wave, the azimuth determination processing unit 10 compares the arrival elevation angle θ _T with a predetermined threshold value, and if the arrival elevation angle θ _T is larger than the predetermined threshold value, since the arrival direction phi _T2 estimated by the estimation processor 8 includes a large Corning error [Delta] [phi _T, the target information management unit the arrival azimuth phi _T1 estimated by the direction estimation processing section 3 as the final estimation result 12 is output.
On the other hand, when the arrival elevation angle θ _T is smaller than the predetermined threshold, the coning error Δφ _T included in the arrival direction φ _T2 estimated by the direction estimation processing unit 8 is small enough to be ignored. Since the estimation accuracy is higher than the influence of the amplitude variation at each element antenna, the arrival direction φ _T2 estimated by the direction estimation processing unit 3 is output to the target information management unit 12 as a final estimation result. .

Here, the direction determination processing unit 10 selects and outputs one of the arrival directions φ _T1 and φ _T2 estimated by the direction estimation processing units 3 and 8. However, the present invention is not limited thereto. Instead, the arrival directions φ _T1 and φ _T2 of both may be combined and output. At this time, the ratio of combining the arrival azimuth φ _T1 and the arrival azimuth φ _T2 may be determined in accordance with the arrival angle θ _T of the radio wave calculated by the elevation angle calculation processing unit 9.

As apparent from the above, according to the first embodiment, the direction estimation is performed by comparing the amplitudes of radio waves received by a plurality of antennas constituting the amplitude comparison method antenna 1 and estimating the arrival direction of the radio waves. A processing unit 3 and an azimuth estimation processing unit 8 that compares the phase differences of radio waves received by a plurality of antennas constituting the phase difference detection method antenna 5 and estimates the arrival direction of the radio waves are provided. Since the azimuth difference between the arrival azimuth estimated by the estimation processing unit 3 and the arrival azimuth estimated by the azimuth estimation processing unit 8 is obtained, and the arrival elevation angle of the radio wave is calculated from the azimuth difference, the desired coverage is Even if it is large, there is an effect that a single incoming radio wave can be reliably detected.
That is, in the case of radio waves coming from the coverage covered by the amplitude comparison method antenna 1 and the phase difference detection method antenna 5, in particular, the azimuth angle and elevation angle of the antenna are controlled, and the incoming radio waves are two-dimensionally controlled. Therefore, the arrival azimuth and the arrival elevation angle of the radio wave can be calculated without performing spatial scanning sequentially, so that it is possible to reliably detect a single incoming radio wave.

  Further, according to the first embodiment, when the arrival elevation angle calculated by the elevation angle calculation processing unit 9 out of the arrival directions estimated by the direction estimation processing units 3 and 8 is larger than the predetermined threshold value, the direction estimation is performed. The arrival direction estimated by the processing unit 3 is selected and output to the target information management unit 12, and when the arrival elevation angle calculated by the elevation angle calculation processing unit 9 is smaller than a predetermined threshold, the direction estimation processing unit 8 estimates Since the received arrival direction is selected and output to the target information management unit 12, the arrival direction with high estimation accuracy can be obtained.

Embodiment 2. FIG.
FIG. 8 is a block diagram showing a radio wave detection apparatus according to Embodiment 2 of the present invention. In the figure, the same reference numerals as those in FIG.
The Rotman lens 21, which is a radio wave lens, synthesizes the phases of RF radio waves received by a plurality of element antennas constituting the phase difference detection antenna 5 to form a multi-beam. The detection circuit 22 converts the multi-beam formed by the Rotman lens 21 into a video signal.
The azimuth estimation processing unit 23 compares the amplitudes of the video signals converted by the detection circuit 22 and estimates the arrival azimuths of the RF radio waves received by the plurality of antennas constituting the phase difference detection antenna 5.
The Rotman lens 21, the detection circuit 22, and the azimuth estimation processing unit 23 constitute second azimuth estimation means.

Next, the operation will be described.
When the plurality of element antennas constituting the phase difference detection type antenna 5 receive RF radio waves, the Rotman lens 21 synthesizes the phases of the RF radio waves to equivalently form a multi-beam.
The detection circuit 22 converts the multi-beam formed by the Rotman lens 21 into a video signal.

When the detection circuit 22 outputs a video signal, the azimuth estimation processing unit 23 obtains a signal level difference between video signals corresponding to RF radio waves received by a plurality of element antennas constituting the phase difference detection antenna 5. The arrival direction of the radio wave radiated from the target is estimated from the signal level difference in the same manner as the amplitude comparison method of the first embodiment.
Others are the same as those in the first embodiment, and the description thereof is omitted.

Even if the Rotman lens 21 and the detection circuit 22 are mounted instead of the receiving unit 6 in FIG. 1 in the first embodiment and a multi-beam is formed by phase synthesis, a coning error occurs in the direction estimation.
When the Rotman lens 21 and the detection circuit 22 are mounted as in the second embodiment, since the Rotman lens 21 physically performs phase synthesis, the receiving unit 6 of the first embodiment uses the phase difference method. The processing speed is faster than sampling and Fourier transforming RF radio waves received by a plurality of element antennas constituting the antenna 5 for use. Therefore, the instantaneous search performance can be further improved as compared with the first embodiment.

  In the second embodiment, the case where the Rotman lens 21 combines the phases of the RF radio waves received by the plurality of element antennas constituting the phase difference detection antenna 5 to form a multi-beam is shown. A radio beam other than the Rotman lens 21 may be used to form a multi-beam.

Embodiment 3 FIG.
In the first and second embodiments described above, the radio wave detection apparatus has been provided with one each of the amplitude comparison method antenna 1 and the phase difference direction detection method antenna 5, but as shown in FIGS. 9 and 10. In addition, the amplitude comparison method antenna 1 and the phase difference detection method antenna 5 may be arranged radially over the entire circumference in a horizontal plane.

FIG. 9 shows an example in which eight amplitude comparison type antennas 1 and four phase difference detection type antennas 5 are arranged, and the number of arrangements may be changed in accordance with the required coverage.
However, in the elevation angle estimation based on the coning error, in principle, no coning error due to the elevation angle occurs in the front direction of the phase difference detection type antenna 5. In order to accurately calculate the elevation angle over the entire circumference, each phase difference It is necessary to arrange a plurality of coverage areas of the direction finding antennas 5 so that the front directions of the respective arrays overlap. As shown in FIG. 10, it is sufficient if there are eight or more phase difference detection type antennas 5.

  As apparent from the above, according to the third embodiment, the amplitude comparison method antenna 1 and the phase difference direction detection method antenna 5 are configured to be arranged radially over the entire circumference in the horizontal plane. The entire circumference can be set as a radio wave coverage area, and therefore, an effect can be obtained in which even a single incoming radio wave arriving from all directions of the spherical surface can be detected instantaneously.

Embodiment 4 FIG.
FIG. 11 is a block diagram showing a radio wave detector according to Embodiment 4 of the present invention. In the figure, the same reference numerals as those in FIG.
The second antenna group for phase difference detection method 5 is composed of a plurality of element antennas arranged in a straight line, and the plurality of phase difference direction detection antennas 5 are arranged in a radial pattern all around the horizontal plane. (See FIG. 12), but some of the element antennas (the black-colored element antennas in FIGS. 11 and 12) constituting the phase difference detection antenna 5 are the first antenna group. (In the example of FIG. 1, it is shared as an element antenna constituting the amplitude comparison antenna 1). Hereinafter, the shared element antenna is referred to as a shared element antenna 5a.

The signal detection selection circuit 31 compares the signal level of the video signal output from the detection circuit 2 and receives the RF radio wave having the highest signal strength among the RF radio waves received by the plurality of shared element antennas 5a. The shared element antenna 5a is detected.
The switching circuit 32 selects only the received radio wave of the phase difference detection antenna 5 including the shared element antenna 5a detected by the signal detection selection circuit 31, and the phase difference calculation processing unit 7 and target radio wave element detection are selected. To the unit 11.

In the fourth embodiment, a part of the elements constituting the phase difference detection type antenna 5 that is not mounted with the amplitude comparison type antenna 1 of FIG. 1 and is arranged radially over the entire circumference in a horizontal plane. The antenna, that is, the shared element antenna 5a of the plurality of phase difference detection type antennas 5 is shared as the element antenna constituting the amplitude comparison type antenna 1 of FIG.
As a result, according to the fourth embodiment, there is an effect that the apparatus scale can be reduced as compared with the first embodiment as much as the amplitude comparison system antenna 1 of FIG. 1 is not mounted.

  In the fourth embodiment, the signal detection / selection circuit 31 compares the signal levels of the video signals output from the detection circuit 2, and the signal is the most signal among the RF radio waves received by the plurality of shared element antennas 5a. A common element antenna 5a receiving a high-intensity RF radio wave is detected, and the received radio wave of the phase difference detection type antenna 5 including the common element antenna 5a detected by the switching circuit 32 by the signal detection selection circuit 31. Is selected and output to the phase difference calculation processing unit 7, so that the phase difference calculation processing unit 7 and the azimuth estimation processing unit 8 in the subsequent stage may actually receive the radio waves emitted by the target. The signal processing based on the received radio wave of the phase detection method antenna 5 having a high value may be performed, that is, the phase detection method antenna having a low possibility of actually receiving the radio wave radiated by the target. 5 since it not perform signal processing based on the received radio waves, than the third embodiment offers an advantage of being able to reduce the computational complexity of subsequent phase difference calculation unit 7 and the direction estimation unit 8.

Embodiment 5 FIG.
13 is a block diagram showing a radio wave detector according to Embodiment 5 of the present invention. In the figure, the same reference numerals as those in FIG.
The antenna rotation driving unit 33 constitutes a rotation driving means for rotating the phase difference detection type antenna 5 in a horizontal plane.

In the fourth embodiment, the plurality of phase difference detection type antennas 5 are arranged radially over the entire circumference in the horizontal plane, and the switching circuit 32 includes the shared element antenna 5a detected by the signal detection selection circuit 31. However, the antenna rotation driving unit 33 rotates the phase difference method searching antenna 5 in a horizontal plane so that the incoming signal is transmitted in the same direction. A desired coverage area to be searched for may be widened.
According to the fifth embodiment, since the number of the phase difference detection type antennas 5 and the receiving units 6 can be reduced, the scale of the apparatus can be reduced, but the above-described embodiment in which the entire circumference is detected simultaneously. Compared to 4, the instantaneous search performance deteriorates.
Although FIG. 13 shows that the antenna rotation driving unit 33 is mounted on the radio wave detection device of FIG. 1, the antenna rotation driving unit 33 may be mounted on the radio wave detection device of FIG.

Embodiment 6 FIG.
In the first embodiment, the antenna for amplitude comparison method 1 and the antenna for phase difference detection method 5 are installed in the same horizontal plane (see FIGS. 3 and 5). As shown, the phase difference detection type antenna 5 may be installed on an installation surface having an angle difference from the installation surface of the amplitude comparison method antenna 1.

According to the principle of estimation of the arrival elevation angle shown in FIG. 7, the larger the angle (elevation angle) from the front direction of the array surface of the phase difference detection antenna 5 is, the larger the coning error is. Conversely, since the coning error is small at an elevation angle close to the horizontal plane, the estimated azimuth difference obtained by the amplitude comparison method and the phase difference detection method is small, and the elevation angle estimation error is also large.
Therefore, when it is necessary to improve the estimation accuracy of radio waves coming from an elevation angle close to a horizontal plane, an elevation offset angle (offset θ) is provided in advance on the installation surface of the amplitude comparison method antenna 1 and the phase difference detection method antenna 5. If this is the case, the coning error becomes large, and therefore the elevation angle of the incoming radio wave close to the horizontal plane can be calculated with higher accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the electromagnetic wave detection apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows the principle of the direction finding process by an amplitude comparison system. It is explanatory drawing which shows the principle of the direction finding process by an amplitude comparison system. It is explanatory drawing which shows the principle of the direction search process by a phase difference method. It is explanatory drawing which shows the principle of the direction search process by a phase difference method. Coordinates _{(γ T, φ T, θ} T) of the radio waves radiated from the target T located in an explanatory diagram showing a coordinate system in the case where the antenna is located at the origin is received. It is explanatory drawing which shows the relationship between a coning error and an elevation angle. It is a block diagram which shows the electromagnetic wave detection apparatus by Embodiment 2 of this invention. It is explanatory drawing which shows the radio wave coverage by the antenna for amplitude comparison methods, and the antenna for phase difference method. It is explanatory drawing which shows the radio wave coverage by the antenna for amplitude comparison methods, and the antenna for phase difference method. It is a block diagram which shows the electromagnetic wave detection apparatus by Embodiment 4 of this invention. It is explanatory drawing which shows the radio wave coverage by the antenna for phase difference direction searching systems. It is a block diagram which shows the electromagnetic wave detection apparatus by Embodiment 5 of this invention. It is explanatory drawing which shows having installed the phase difference method antenna for the installation surface which has an angle difference with the installation surface of the amplitude comparison method antenna.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Antenna for amplitude comparison systems (1st antenna group) 2 Detection circuit (1st azimuth estimation means) 3 Direction estimation processing part (1st azimuth estimation means) 4 Timing signal generation part 5 Phase difference method Search system antenna (second antenna group), 5a shared element antenna, 6 receiver (second azimuth estimation means), 7 phase difference calculation processing section (second azimuth estimation means), 8 azimuth estimation processing section ( Second azimuth estimation means), 9 elevation calculation processing section (elevation angle calculation means), 10 azimuth determination processing section (selection means), 11 target radio wave specification detection section, 12 target information management section, 21 Rotman lens (radio lens, (Second azimuth estimation means), 22 detector circuit (second azimuth estimation means), 23 azimuth estimation processing section (second azimuth estimation means), 31 signal detection selection circuit, 32 switching circuit, 33 antenna rotation drive section ( Rotation drive Stage).

Claims (8)

  The first antenna group in which a plurality of antennas are arranged radially and the amplitude of radio waves received by the plurality of antennas constituting the first antenna group are compared to estimate the arrival direction of the radio waves Azimuth direction estimation means, a second antenna group in which a plurality of antennas are arranged in an array, and a phase of a radio wave received by a plurality of antennas constituting the second antenna group are compared. A second azimuth estimating means for estimating the arrival azimuth; a difference between the arrival azimuth estimated by the first azimuth estimating means and the arrival azimuth estimated by the second azimuth estimating means; A radio wave detection apparatus comprising an elevation angle calculation means for calculating an arrival elevation angle of the radio wave.   The first antenna group in which a plurality of antennas are arranged radially and the amplitude of radio waves received by the plurality of antennas constituting the first antenna group are compared to estimate the arrival direction of the radio waves Direction estimation means, a second antenna group in which a plurality of antennas are arranged in an array, and a phase of radio waves received by the plurality of antennas constituting the second antenna group to form a multi-beam And comparing the amplitudes of the beam terminals of the multi-beams to estimate the arrival direction of the radio wave, the arrival direction estimated by the first direction estimation unit, and the second direction. A radio wave detection apparatus comprising: an elevation angle calculation unit that obtains an azimuth difference of arrival directions estimated by the estimation unit and calculates an arrival elevation angle of the radio wave from the azimuth difference.   A radio wave lens for synthesizing phases of radio waves received by a plurality of antennas constituting the second antenna group to form a multi-beam, a detection circuit for converting the multi-beam formed by the radio wave lens into a video signal, 3. The radio wave according to claim 2, wherein the second azimuth estimating means comprises an azimuth estimation processing unit for comparing the amplitude of the video signal converted by the detection circuit and estimating the arrival azimuth of the radio wave. Detecting device.   Of the arrival azimuths estimated by the first and second azimuth estimation means, if the arrival elevation angle calculated by the elevation angle calculation means is larger than a predetermined threshold, the arrival azimuth estimated by the first azimuth estimation means is There is provided selection means for selecting and outputting, and selecting and outputting the arrival direction estimated by the second direction estimation means when the arrival elevation angle calculated by the elevation angle calculation means is smaller than a predetermined threshold value. The radio wave detection device according to any one of claims 1 to 3, wherein:   The radio wave detector according to any one of claims 1 to 4, wherein the first and second antenna groups are arranged radially over the entire circumference in a horizontal plane.   The second antenna group is arranged radially over the entire circumference in a horizontal plane, and a part of the antennas constituting the second antenna group is shared as an antenna constituting the first antenna group. The radio wave detector according to any one of claims 1 to 4.   The radio wave detection device according to any one of claims 1 to 4, further comprising a rotation driving unit that rotates the second antenna group in a horizontal plane.   5. The radio wave detection device according to claim 1, wherein the second antenna group is installed on an installation surface having an angle difference from the installation surface of the first antenna group.

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