JPH10227688A - Aircraft noise identifying apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aircraft noise identifying apparatus for identifying whether it is an aircraft noise or not even if a difference between an aircraft noise level and the other noise level is not sufficient. SOLUTION: The aircraft noise identifying apparatus comprises a sound wave type direction identifier 1 for detecting sound generated from an aircraft to output a direction signal αm responsive to a bearing of the aircraft, a radio type direction identifier 2 for detecting a radio wave generated from the aircraft to output a direction signal αa responsive to the bearing of the aircraft, a time difference detector 3 for outputting a time difference td between the signal αm of the identifier 1 and the signal αa of the identifier 2, and a deciding unit 4 for deciding that a sound source is the same as a radio source if the difference td is continued at the same value for a predetermined time or longer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aircraft noise discriminating apparatus for determining whether a noise source is an aircraft noise.

[0002]

2. Description of the Related Art Conventionally, in automatic measurement of noise caused by a flying aircraft, a sound source is identified by sound from the aircraft caused by the aircraft moving away from the measurement point after approaching the measurement point, generally the sound pressure level of the noise. Is measured, and the change of the chevron shape is measured, and the time width at which the sound pressure level is reduced from the peak value by a predetermined level (for example, α dB), or the duration during which the sound pressure equal to or higher than the predetermined sound pressure level is obtained When the value exceeds a predetermined threshold value, it is determined that the noise is caused by the passage of the aircraft (for example, Japanese Utility Model Publication No. 60-15
No. 143).

However, in such a method, regardless of the type of sound source, for example, whether it is a moving sound source or a stationary sound source, a ground sound source, or an air sound source, a noise source satisfying the above-described conditions is used. There is a disadvantage that all the sounds are determined as aircraft noise. For example, even if an attempt is made to measure only noise from an aircraft in flight, a similar measurement value can be obtained by noise from a ground vehicle such as an automobile passing near the measurement point.

[0004] In order to solve such a problem, an apparatus described in Japanese Patent Publication No. 61-13169 has been proposed. This apparatus uses two microphones that are vertically separated from each other, and detects a time difference between a sound arriving from above, that is, a sound of an aircraft reaching the two microphones, using a cross-correlation function.

[0005]

However, the difference between the aircraft noise level and other noise levels is not always sufficient, and in the prior art, the peak position of the correlation is sometimes misidentified and determined. There is a problem that an error occurs in the result.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide an airplane even when the noise level of the aircraft is not sufficiently different from other noise levels. It is an object of the present invention to provide an aircraft noise discriminating apparatus capable of discriminating whether or not noise is generated.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is a sound direction identification means for detecting a sound emitted from an aircraft and outputting a signal corresponding to the orientation of the aircraft, and a sound emitted from the aircraft. A radio wave direction identification means for detecting a radio wave and outputting a signal corresponding to the direction of the aircraft, and calculating a similarity between an output signal of the sound wave direction identification means and an output signal of the radio wave direction identification means, When the similarity is equal to or larger than a predetermined value, the sound source and the radio wave source are determined to be the same.

According to a second aspect of the present invention, there is provided a sound wave direction identification means for detecting a sound emitted from an aircraft and outputting a signal corresponding to the direction of the aircraft, and a signal corresponding to the direction of the aircraft by detecting a radio wave emitted from the aircraft. Radio wave direction identification means for outputting a time difference detection means for outputting a time difference between an output signal of the sound wave direction identification means and an output signal of the radio wave direction identification means,
If the time difference continues to be the same value for a predetermined time or more, the sound source and the radio wave source are determined to be the same.

According to a third aspect of the present invention, there is provided a sound wave direction identification means for detecting a sound emitted from an aircraft and outputting a signal corresponding to the direction of the aircraft, and a signal corresponding to the direction of the aircraft by detecting a radio wave emitted from the aircraft. A radio wave direction identification means for outputting a cross-correlation function between the output signal of the sound wave direction identification means and the output signal of the radio wave direction identification means; and a maximum of the cross-correlation function. When the value has a value equal to or greater than a predetermined value at the same position, a determination means is provided for determining that the sound source and the radio wave source are the same.

According to a fourth aspect of the present invention, there is provided a sound wave direction identification means for detecting a sound emitted from an aircraft and outputting a signal corresponding to the direction of the aircraft, and a signal corresponding to the direction of the aircraft by detecting a radio wave emitted from the aircraft. Radio wave direction discriminating means, and the output signal of the sound wave direction discriminating means and the output signal of the radio wave direction discriminating means are treated as a two-dimensional line drawing of time and azimuth, and the similarity between these two kinds of line drawing Is provided with a pattern matching means for evaluating by using pattern matching.

According to a fifth aspect of the present invention, a sound level meter is attached to the aircraft noise identification device according to the first, second, third or fourth aspect, and the indicated value of the noise level meter corresponds to the determination result of the aircraft noise identification device. A recording means for recording the data is provided.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a configuration diagram of an aircraft noise identification device according to the first embodiment of the present invention, FIG. 2 is a configuration diagram of a sound direction identification device, FIG. 3 is a top view showing an arrangement of microphones, and FIG. FIG. 5 is an explanatory diagram showing the arrangement of antennas, FIG. 6 is a diagram showing the difference in azimuth between radio waves and sound, and FIG. 7 is a configuration of an aircraft noise discriminating device according to the second embodiment. FIG. 8 is a block diagram of the aircraft noise discriminating apparatus according to the third aspect of the present invention, FIG. 9 is a block diagram of the aircraft noise discriminating apparatus according to the fourth aspect of the present invention, and FIG. FIG. 11, FIG. 11 is a diagram in which the azimuth from which a radio wave arrives is pixelated, FIG. 12 is a diagram, in which an azimuth from which a certain sound arrives is pixelated, and FIG. 13 is a configuration of the aircraft noise identification device according to the invention of claim 5. FIG.

As shown in FIG. 1, an aircraft noise discriminating apparatus S0 detects a sound emitted from an aircraft and outputs a directional signal αm corresponding to the azimuth of the aircraft. Radio wave direction identification device 2 which detects a radio wave emitted by the vehicle and outputs a direction signal αa corresponding to the direction of the aircraft
And the azimuth signal αm of the sound wave type directional identification device 1 and the azimuth signal αa of the radio wave type directional identification device 2 are calculated, and when the similarity is equal to or greater than a predetermined value, the sound source and the radio source are the same. And a similarity determination device 0 which determines that there is a similarity.

As shown in FIG. 2, the sound wave type azimuth discriminating apparatus 1 includes three omnidirectional microphones M1, M2, M3,
A correlation operation unit E1 for calculating a correlation function between the output signal of the microphone M1 and the output signal of the microphone M2; a correlation operation unit E2 for calculating a correlation function between the output signal of the microphone M1 and the output signal of the microphone M3;
A delay detection unit D1 for obtaining a delay time τx of an output signal of the microphone M2 with respect to the output signal of the microphone M1;
A delay detecting unit D2 for obtaining a delay time τy of the output signal of the microphone M3 with respect to the output signal of
Azimuth angle calculation unit P1 for calculating the azimuth angle αm of the aircraft from y
Consists of

Three omnidirectional microphones M1, M2,
As shown in FIG. 3, M3 is disposed on a horizontal plane such that a straight line connecting the microphones M1 and M2 and a straight line connecting the microphones M1 and M3 are orthogonal to each other.

Assuming that the distance between the microphone M1 and the microphone M2 is L1 and the distance between the microphone M1 and the microphone M3 is L2, it is not always necessary that L1 = L2, and L1 ≠ L2. In short, microphone M
Direction for viewing microphone M2 from 1 (M1 and M2 directions)
It is only necessary that the sound from the microphone M1 and the microphone M2 does not reach the microphone M1 and the microphone M2 at the same time, and that the sound from the direction in which the microphone M1 looks at the microphone M3 (M1 and M3 directions) does not reach the microphone M1 and the microphone M3 at the same time. Because. Further, when the azimuth is detected in an absolute direction, the direction of M1 · M2 or M1 · M3
The direction can be set to any direction of north, south, east, west.

For example, the M1 · M2 direction is 0 °, the M1 · M
If the three directions are 90 °, the microphones M1, M2, M
The azimuth αm of the aircraft, which is the sound source of the sound captured in Step 3, is obtained by the azimuth calculation unit P1 as follows.

When τx ≧ 0 and τy ≧ 0, αm =
tan ^-1 (τy ÷ τx) [radian].

When τx <0, αm = π + tan ⁻¹
(Τy ÷ τx) [radian].

When τx ≧ 0 and τy <0, αm =
2π + tan ⁻¹ (τy ÷ τx) [radian].

Next, as shown in FIG. 4, the radio wave direction identification device 2 has three vertical antennas (omnidirectional in a horizontal plane).
A1, A2, and A3, amplification sections A4, A5, and A6 that amplify output signals of the vertical antennas A1, A2, and A3, and phase comparison between the output signal of the amplification section A4 and the output signal of the amplification section A5. A phase comparison unit C1 for converting a phase difference of 180 ° (± π radian) into a voltage of ± eV, and a phase of an output signal of the amplification unit A4 and a phase of an output signal of the amplification unit A6 are compared to be ± 180 °.
A phase comparison unit C2 for converting a phase difference of (± π radians) into a voltage of ± eV; low-pass filters F1 and F2 for averaging output signals of the phase comparison units C1 and C2 to remove high-frequency noise such as spike noise; A / D converter A for converting the output signal of low-pass filter F1 to digital code Ax
7, a voltage comparison unit A8 for obtaining the sign of the output signal of the low-pass filter F2, and an azimuth calculation unit P2 for calculating the azimuth αa of the aircraft from the digital code Ax and the sign.

In the embodiment of the present invention, the response radio wave (frequency 1090 MHz) of the secondary surveillance radar (SSR) is detected as the radio wave emitted by the aircraft detected by the radio wave direction identification device 2.
z) is used. However, the radio wave emitted by the aircraft is SS
It is not limited to the response radio wave of R.

As shown in FIG. 5, the three vertical antennas (omnidirectional in a horizontal plane) A1, A2, and A3 are orthogonal to a straight line connecting the antennas A1 and A2 and a straight line connecting the antennas A1 and A3. It is arranged to be. The distance between the antenna A1 and the antenna A2 and the distance between the antenna A1 and the antenna A3 are each 13.8 cm (（wavelength of the SSR response frequency of 1090 MHz). Furthermore,
When the azimuth is detected in an absolute direction, the antenna A
The direction connecting the antenna 1 to the antenna A2 or the direction connecting the antenna A1 to the antenna A3 may be adjusted to any one of north, south, east and west.

For example, assuming that the direction connecting antenna A1 and antenna A2 is 0 ° and the direction connecting antenna A1 and antenna A3 is 90 °, the azimuth angle of the aircraft that is the source of radio waves captured by antennas A1, A2 and A3 αa is obtained by the azimuth angle calculation unit P2 as follows.

When the sign of the voltage comparison unit A8 is positive, α
a = cos ^-1 (Ax) [radian].

When the sign of the voltage comparison unit A8 is negative, α
a = 2π-cos ^-1 (Ax) [radian].

The operation of the aircraft noise discriminating apparatus S0 having the above-described structure will be described. The azimuth αm at which a time-varying sound arrives is detected by the acoustic azimuth identification device 1 with respect to the sound and radio waves emitted by a flying aircraft, and the azimuth αa at which the time-varying radio wave arrives is a radio azimuth. It is detected by the identification device 2.

Next, as shown in FIG. 6, the time-varying azimuth αm and the time-varying azimuth αa detected by the azimuth discriminating devices 1 and 2 are input to the similarity determination device 0. Then, the similarity determination device 0 calculates the similarity between the azimuth αm due to the sound wave and the azimuth αa due to the radio wave.
When the similarity is equal to or greater than a predetermined value, the sound source and the radio wave source are the same, that is, the sound measured by the sound wave direction identification device 1 is determined to be aircraft noise.

As described above, by calculating the similarity between the azimuth αm at which the sound emitted from the flying aircraft arrives and the azimuth αa at which the SSR radio wave arrives, it is easy to identify whether the noise is caused by the aircraft. Become.

As shown in FIG. 7, the aircraft noise discriminating apparatus S1 according to claim 2 detects a sound emitted from the aircraft and outputs a directional signal αm corresponding to the azimuth of the aircraft. Radio wave direction identification device 2 which detects a radio wave emitted by the vehicle and outputs a direction signal αa corresponding to the direction of the aircraft
And a time difference detection unit 3 that outputs a time difference td between the direction signal αm of the sound wave type direction identification device 1 and the direction signal αa of the radio wave type direction identification device 2, and the case where the time difference td continues the same value for a predetermined time or more. The determination unit 4 determines that the sound source and the radio wave source are the same.

The sound wave direction identification device 1 and the radio wave direction identification device 2 have the same configuration as the sound wave direction identification device 1 and the radio wave direction identification device 2 in the aircraft noise identification device S0 of the first aspect. The description is omitted.

The operation of the aircraft noise discriminating apparatus S1 constructed as described above will now be described. The azimuth αm at which a time-varying sound arrives is detected by the acoustic azimuth identification device 1 with respect to the sound and radio waves emitted by a flying aircraft, and the azimuth αa at which the time-varying radio wave arrives is a radio azimuth. It is detected by the identification device 2.

Next, as shown in FIG. 6, the time-varying azimuth αm and the time-varying azimuth αa detected by the azimuth discriminating devices 1 and 2 are input to the time difference detecting unit 3. Then, in the time difference detection unit 3, the azimuth α due to the sound wave
The time difference td between m and the azimuth αa by radio waves is calculated. Then, when the time difference td continues to be the same value for a predetermined time or more, the determination unit 4 determines that the sound source and the radio wave source are the same, that is, the sound measured by the sound wave direction identification device 1 is the aircraft noise.

Thus, by comparing the temporal change of the azimuth αm at which the sound emitted from the flying aircraft arrives with the temporal change of the azimuth αa at which the SSR radio wave arrives,
It is easy to determine whether the noise is caused by an aircraft.

As shown in FIG. 8, the aircraft noise discriminating apparatus S2 according to a third aspect includes a sound wave direction discriminating apparatus 5 for detecting a sound emitted from an aircraft and outputting a direction signal αm corresponding to the direction of the aircraft. Radio wave direction discriminating device 6 which detects a radio wave emitted from the vehicle and outputs a direction signal αa corresponding to the direction of the aircraft.
A cross-correlation function calculator 7 for calculating a cross-correlation function between the azimuth signal αm of the sound wave type azimuth identification device 5 and the azimuth signal αa of the radio wave type azimuth identification device 6; When it has the above values, the sound source and the radio wave source are determined to be the same.

The sound wave direction identification device 5 and the radio wave direction identification device 6 have the same configuration as the sound wave direction identification device 1 and the radio wave direction identification device 2 in the aircraft noise identification device S0 of the first aspect. The description is omitted.

The operation of the aircraft noise discriminating apparatus S2 constructed as described above will now be described. The cross-correlation function calculation unit 7 calculates a cross-correlation function between time-series data with respect to the azimuth αm of the sound wave detected by the sound wave direction identification device 5 and the azimuth αa of the radio wave detected by the radio wave direction identification device 6. I do.

As shown in FIG. 6, the azimuth αm at which the sound arrives is delayed by a certain time with respect to the azimuth αa at which the radio wave arrives, and changes substantially similarly. However, since any measurement data (azimuths αm, αa) actually contains errors and noises, it is not easy to obtain the correlation between the measurement data as it is. Therefore, if a cross-correlation function is obtained by applying a statistical method to the measurement data, in the case of an event accompanying the passage of an aircraft, a large correlation value is shown for each change, and errors and noise are removed because there is no correlation. .

Next, the judgment unit 8 compares the maximum value of the cross-correlation function calculated by the cross-correlation function calculation unit 7 with a preset threshold value, and determines that the maximum value of the cross-correlation function is equal to or larger than the threshold value. If there is, the sound source and the radio wave source are the same, that is, it is determined that the sound measured by the sound wave direction identification device 5 is the aircraft noise. In this manner, a stable identification result as to whether or not the noise is caused by the aircraft can be obtained.

As shown in FIG. 9, the aircraft noise discriminating apparatus S3 according to claim 4 includes a sound wave direction discriminating apparatus 9 for detecting a sound emitted from an aircraft and outputting a direction signal αm corresponding to the direction of the aircraft, Radio direction identification device 10 which detects a radio wave emitted by the vehicle and outputs a direction signal αa corresponding to the direction of the aircraft.
And the azimuth signal αm of the sound wave type azimuth identification device 9 and the azimuth signal αa of the radio wave type azimuth identification device 10 as time and azimuth angles αm, α
The pattern matching device 11 is treated as a two-dimensional line drawing a and evaluates the similarity between the two kinds of line drawings by pattern matching.

The sound wave direction identification device 9 and the radio wave direction identification device 10 have the same structure as the sound wave direction identification device 1 and the radio wave direction identification device 2 in the aircraft noise identification device S0 of the first aspect. The description is omitted.

The pattern matching device 11 comprises a pixelizing unit 12, a correlation calculating unit 13, and a determining unit 14.
The operation of the aircraft noise identification device S3 according to claim 4 configured as described above will be described. The pixilating unit 12 calculates the azimuth α measured by the sound wave type azimuth identification device 9 from moment to moment.
m and the azimuth α measured by the radio wave direction identification device 10
a is recorded together with the time information.

For example, as shown in FIG. 10 and FIG. 11, the recording time interval was measured every 1 second, and the azimuth was measured in 180 storage areas provided every 2 ° (π / 90 radians). One area corresponding to the azimuths αm and αa is recorded as “1” (black part in the figure), and the other area is recorded as “0” (white part in the figure). 10 and 11, the interval between the vertical lines is equivalent to 1 second, and the interval between the horizontal lines is 2 ° (π / π).
90 radians).

Thus, the 180 provided at every azimuth angle of 2 °
Pixelization means that any one of the storage areas is set to “1” as a representative, the other area is set to “0”, and the measured azimuths αm and αa are binarized and recorded. 6 corresponds to processing a continuous curve of the azimuth angle αm and the azimuth angle αa into a discontinuous waveform as shown in FIGS. 10 and 11.

Next, the correlation calculation unit 13 determines whether or not the discontinuous waveform of the pixelated azimuth αm shown in FIG. 10 matches the discontinuous waveform of the pixelated azimuth αa shown in FIG. In order to obtain judgment information, a cross-correlation function φxy (△) of the pixelized azimuth angle αm and azimuth angle αa is obtained.
Calculate t). The cross-correlation is calculated by shifting one time axis (azimuth angle αm) shown in FIG. 10 with respect to the other time axis (azimuth angle αa) shown in FIG.
Find the value of the largest correlation.

Next, when the value of the correlation obtained by the correlation calculator 13 is larger than a preset threshold value, the determination unit 14 determines that the sound source and the radio wave source are the same. The value of the correlation obtained by the correlation operation unit 13 means the similarity of the change in the numerical values of different populations. Comparing radio waves with sound waves, the azimuth α at which radio waves arrive
The change in a is observed earlier, and the azimuth αm at which the sound arrives changes so as to follow.

In the case of the azimuth αm and the azimuth αa shown in FIGS. 10 and 11, when the time axis of the azimuth αm of the sound is shifted so as to advance by 2 seconds, the maximum value of the correlation is “1”. Therefore, the threshold value set in the determination unit 14 is set to, for example, 0.
If it is set to 8, the sound source and the radio wave source are the same, that is, the sound is measured by the sound wave direction identification device 9 and the sound is determined to be aircraft noise.

When a waveform as shown in FIG. 12 is obtained as the azimuth of the sound measured by the sound wave type azimuth discriminating apparatus 9, the maximum value of the correlation with the azimuth αa shown in FIG. If the threshold set in advance in the determination unit 14 is, for example, 0.8, the sound source and the radio wave source are not the same, and the sound measured by the sound wave direction identification device 9 is the noise of the aircraft. Not determined.

As described above, the output signals of the sound wave type azimuth discriminating device 9 and the radio wave type directional discriminating device 10 are converted into time and azimuth angle α.
m and αa are treated as two-dimensional line drawings, and the similarity between these two types of line drawings is evaluated by pattern matching for calculating the two-dimensional cross-correlation and obtaining the maximum correlation value. The cancellation and the delay time can be clearly measured, and it is easy to determine whether the noise is caused by the aircraft. In particular, when the azimuth angles αm and αa change gradually, the correlation function also changes slowly, and it is difficult to grasp features from the correlation function, which is effective.

As shown in FIG. 13, the aircraft noise discriminating apparatus S4 according to the fifth aspect is provided with a noise meter 15 in the aircraft noise discriminating apparatuses S0, S1, S2, and S3 according to the first, second, third, and fourth aspects.
And a recorder 16 are attached, and the indicated values of the sound level meter 15 correspond to the judgment results of the aircraft noise identification devices S0, S1, S2, and S3, and these indicated values and the judgment results are recorded by the recorder 16.

Aircraft noise discriminating devices S0, S1, S2, S
3 determines that the sound source and the radio wave source are the same, it is clear that the noise level simultaneously measured by the sound level meter 15 and recorded in the recorder 16 is the noise level of the aircraft identified as the noise source. Prove.

[0052]

As described above, according to the first aspect of the present invention, the azimuth from which the sound from the flying aircraft arrives,
By determining the degree of similarity to the azimuth at which the radio wave emitted from the aircraft arrives, it is easy to determine whether the noise is caused by the aircraft.

According to the invention of claim 2, the temporal change of the azimuth at which the sound emitted by the flying aircraft arrives is compared with the temporal change of the azimuth at which the radio wave emitted by the aircraft arrives. It is easy to determine whether the noise is noise.

According to the third aspect of the present invention, the azimuth angle at which the measured sound arrives and the azimuth angle at which the radio wave arrives are subjected to a statistical method to determine the mutual relationship. Indicates a large correlation value, and errors and noises are removed because of no correlation, and a stable identification result as to whether or not the noise is caused by an aircraft can be obtained.

According to the fourth aspect of the present invention, the measured azimuth at which sound arrives and the azimuth at which radio waves arrive are treated as two-dimensional line drawings, and the similarity between these two types of line drawings is evaluated by pattern matching. Since the maximum correlation value is obtained by calculating the two-dimensional cross-correlation, errors and noises are canceled by calculating the two-dimensional cross-correlation, and the delay time can be clearly measured. Therefore, a stable identification result as to whether or not the noise is caused by the aircraft can be obtained.

According to the fifth aspect of the present invention, the correspondence between the aircraft identified as the noise source and the noise level thereof can be clearly recorded.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an aircraft noise identification device according to the invention of claim 1;

FIG. 2 is a configuration diagram of a sound wave type direction identification device.

FIG. 3 is a top view showing the arrangement of microphones.

FIG. 4 is a configuration diagram of a radio wave direction identification device.

FIG. 5 is an explanatory diagram showing the arrangement of antennas.

FIG. 6 is a diagram showing a difference in change in azimuth angle between radio waves and sound.

FIG. 7 is a configuration diagram of an aircraft noise identification device according to the invention of claim 2;

FIG. 8 is a configuration diagram of an aircraft noise identification device according to the invention of claim 3;

FIG. 9 is a configuration diagram of an aircraft noise identification device according to the invention of claim 4;

FIG. 10 is a diagram in which the azimuth angle at which sound arrives is pixelated.

FIG. 11 is a diagram in which the azimuth angle at which a radio wave arrives is pixelated.

FIG. 12 is a diagram in which the azimuth angle at which a certain sound arrives is pixelated.

FIG. 13 is a configuration diagram of an aircraft noise identification device according to the invention of claim 5;

[Explanation of symbols]

0: Similarity determination device, 1, 5, 9 ... Sound wave direction identification device, 2, 6, 10 ... Radio wave direction identification device, 3 ... Time difference detection unit, 4, 8, 14 ... Determination unit, 7 ... Cross-correlation Function calculation unit, 11: Pattern matching device, 12: Pixel conversion unit, 13: Correlation calculation unit, 15: Sound level meter, 16: Recorder,
A1, A2, A3 ... vertical antenna, M1, M2, M3 ...
Microphone, S0, S1, S2, S3, S4... Aircraft noise identification device.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koichi Makino 3-20-41 Higashimoto-cho, Kokubunji-shi, Tokyo Inside the Kobayashi Science Research Institute

Claims (5)

[Claims] 1. A sound wave direction identification means for detecting a sound emitted from an aircraft and outputting a signal corresponding to the direction of the aircraft, and a radio wave type detecting a radio wave emitted from the aircraft and outputting a signal corresponding to the direction of the aircraft. Azimuth identifying means, calculating a similarity between the output signal of the sound wave azimuth identifying means and the output signal of the radio wave azimuth identifying means, and when the similarity is equal to or greater than a predetermined value, the sound source and the radio wave source are the same. An aircraft noise identification device, comprising: a similarity determination unit that determines that the aircraft noise level is zero. 2. A sound wave direction identification means for detecting a sound emitted from an aircraft and outputting a signal according to the direction of the aircraft, and a radio wave type detecting a radio wave emitted from the aircraft and outputting a signal according to the direction of the aircraft. Azimuth identification means, time difference detection means for outputting a time difference between the output signal of the acoustic azimuth identification means and the output signal of the radio wave azimuth identification means, and a sound source if the time difference continues the same value for a predetermined time or more. An aircraft noise identification device, comprising: a determination unit that determines that a radio wave source is the same as a radio wave source. 3. A sound wave direction identification means for detecting a sound emitted from an aircraft and outputting a signal according to the direction of the aircraft, and a radio wave type detecting a radio wave emitted from the aircraft and outputting a signal according to the direction of the aircraft. Azimuth identification means, a cross-correlation function calculation means for calculating a cross-correlation function between the output signal of the acoustic azimuth identification means and the output signal of the radio wave azimuth identification means, An aircraft noise identification device comprising: a determination unit that determines that a sound source and a radio wave source are the same when the value has a predetermined value or more. 4. A sound wave direction identification means for detecting a sound emitted from an aircraft and outputting a signal corresponding to the direction of the aircraft, and a radio wave type detecting a radio wave emitted from the aircraft and outputting a signal corresponding to the direction of the aircraft. The azimuth identification means, the output signal of the sound wave azimuth identification means and the output signal of the radio wave azimuth identification means are treated as two-dimensional line drawings of time and azimuth, and the similarity between these two types of line drawings is evaluated by pattern matching. An aircraft noise identification device, comprising: 5. A recording device comprising a noise level meter attached to the aircraft noise identification device according to claim 1, 2, 3 or 4, and recording the indicated value of the noise level meter and the determination result of the aircraft noise identification device in association with each other. An aircraft noise discriminating apparatus characterized by comprising means.