JP7052501B2 - Sound wave generator for lath radar and lath radar - Google Patents

Description

The present invention relates to a sound wave generator for a lath radar and a lath radar, specifically, a sound wave generator for a lath radar and a lath radar capable of generating sound waves having high directivity.

Conventionally, a radio wave sound measurement system (RASS (Radio Acoustic Sounding System) radar) is known as a system for continuously and remotely measuring the wind direction, wind speed, and temperature altitude distribution in the upper atmosphere (for example, RASS). See Patent Document 1).

The lath radar emits sound waves from a sound source on the ground toward the observed airspace above, and also emits radio waves from the Doppler radar toward the observed airspace. Then, a radio wave that is reflected by the sound wave surface (rough wave surface) of the sound wave and whose frequency is shifted by the Doppler effect is received on the ground, and the propagation speed of the sound wave in the observed airspace is measured from the Doppler shift amount of the radio wave. Furthermore, the temperature in the observed airspace is calculated by utilizing the property that the propagation velocity of sound waves changes depending on the temperature of the medium.

Japanese Unexamined Patent Publication No. 2017-172982

The patent document describes a technique for transmitting sound waves toward the sky from a directional speaker installed upward. However, in such a configuration, the piezoelectric element provided in the directional speaker gets wet when it rains or snows. On the other hand, when the directional speaker is installed facing downward and the reflector for reflecting the sound wave is arranged directly under the directional speaker, the sound reflected by the reflector hits the directional speaker. In this case, the sound wave cannot be properly transmitted to the sky, and the sound that hits the directional speaker propagates to the surroundings, resulting in large sound leakage.

The present invention has been made in view of the above circumstances, and the problem to be solved by the present invention is to be able to appropriately send sound waves to the sky and suppress sound leakage to the surroundings. , A sound wave generator for a lath radar, and a lath radar.

In order to solve the above-mentioned problems, the present invention constitutes the following sound wave generator for a lath radar.

(1) Sound waves and radio waves are sent toward the sky, the sound velocity in the observed airspace is measured from the frequency shift amount due to the Doppler effect of the radio waves reflected by the sound wave surface, and the temperature in the observed airspace is calculated from the measured sound velocity. A sound wave generator for a lath radar, the first reflecting plate arranged at an angle, the second reflecting plate inclined at a position facing the first reflecting plate, and the first reflecting plate. A parametric speaker installed so as to output sound waves downward is provided on a gantry provided above the above, and the sound waves output from the parametric speakers are reflected by the first reflector and then the first. (2) Sound waves transmitted toward the second reflector and transmitted from the first reflector toward the second reflector are reflected by the second reflector and then transmitted toward the sky, and the first A sound wave generator for a lath radar, wherein a secondary reflector that is inclined with respect to the second reflector is provided at an end of the second reflector on the opposite side of the first reflector.

(2) The sound wave generation for the lath radar according to (1) , wherein the sound wave output from the parametric speaker is reflected by the first reflector and the second reflector and then transmitted vertically upward. Device.

(3) The sound wave generator for a lath radar according to (1) or (2) , wherein the parametric speaker is installed so as to output sound waves vertically downward.

(4) The sound wave generator for a lath radar according to (3) , wherein the first reflector and the second reflector are arranged at an angle of between 40 and 50 degrees from a horizontal plane.

(5) The sound wave generator for a lath radar according to (4) , wherein the parametric speaker is installed in an area above the first reflector.

( 6) The parametric speaker is installed at a position where the vertical distance from the center to the first reflector is smaller than the horizontal length of the parametric speaker in the slope direction of the first reflector. The sound wave generator for the last radar according to 5) .

(7) In the parametric speaker, the horizontal distance between the central portion and the boundary surface between the region above the first reflector and the region above the second reflector is the slope of the first reflector. The sound wave generator for a lath radar according to (6) , which is installed at a position smaller than the horizontal length of the parametric speaker in the direction.

(8) The sound wave generation for the lath radar according to any one of (1) to (7), wherein the first reflector and the second reflector are formed of hard concrete, foam concrete, or mortar. Device.

In addition, the present invention constitutes the following lath radar in order to solve the above-mentioned problems.

The sound wave generator according to any one of (1) to (8) and the sound wave reflected by the sound wave surface of the sound wave transmitted from the sound wave generator toward the sky by transmitting a radio wave toward the sky. A lath radar comprising a Doppler radar that receives and measures the sound wave in the observed airspace from the frequency shift amount due to the Doppler effect, and a processing device that calculates the temperature in the observed airspace from the sound wave measured by the Doppler radar.

According to the sound wave generator for a lath radar and the lath radar according to the present invention, it is possible to appropriately send sound waves to the sky and suppress sound leakage to the surroundings.

The figure which showed the system of the last radar which concerns on this embodiment. The figure explaining the principle of measuring the air temperature in the sky with a lath radar. The front perspective view which showed the sound wave generation part which concerns on 1st Embodiment. The rear perspective view which showed the sound wave generation part which concerns on 1st Embodiment. The side view which showed the sound wave generation part which concerns on 1st Embodiment. (A) and (b) are a plan view and a side view showing the experimental conditions of the first experiment in the sound wave generating part, respectively. (A) and (b) are a plan view and a side view showing the experimental conditions of the second experiment in the sound wave generating part, respectively. The front perspective view which showed the sound wave generation part which concerns on the 2nd Embodiment. The side view which showed the sound wave generation part which concerns on 2nd Embodiment. The figure which showed the experimental result of the 3rd experiment in the sound wave generation part which concerns on 2nd Embodiment.

First, a schematic configuration of a lath radar according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 shows a lath radar system. Further, FIG. 2 is a diagram illustrating a principle of measuring the air temperature in the sky with a lath radar. In FIG. 1, reference numeral 1 is a sound wave generator, reference numeral 2 is a Doppler radar, and reference numeral 3 is a processing device.

In the lath radar of the present embodiment, the sound wave generator 1 includes a sound wave generator 40 according to the first embodiment as a configuration for transmitting sound waves toward the sky (see FIGS. 3 and 4). ). As shown in FIGS. 3 and 4, the sound wave generation unit 40 is arranged below the parametric speaker 4, the gantry 41 that supports the parametric speaker 4, the control box 42 provided on the gantry 41, and the parametric speaker 4. It includes a first reflecting plate 21 and a second reflecting plate 22, and a first supporting member 23 and a second supporting member 24 that support the first reflecting plate 21 and the second reflecting plate 22.

In the control box 42, various devices such as an oscillator 5, a switching means 6, a phase controller 7, and an amplifier 8 constituting the sound wave generator 1 are electrically connected to the processing device 3 and the parametric speaker 4. It is contained. Then, as shown in FIG. 1, the sound wave generator 1 generates a sound wave signal by the oscillator 5. Then, the oscillator 5 sends the generated sound wave signal to the phase controller 7 via the switching means 6, amplifies it to a predetermined output by the amplifier 8, and then inputs it to the parametric speaker 4. The parametric speaker 4 generates a sound wave having a predetermined frequency and a predetermined phase based on the input sound wave signal and sends the sound wave to the sky.

As shown in FIGS. 1 and 2, the Doppler radar 2 includes a transmitting antenna 9 and a receiving antenna 10, and sends a signal from the radar transmitter 11 to the transmitting antenna 9 to transmit the exploration radio wave D toward the sky. Then, the receiving antenna 10 receives the reflected radio wave R generated by the sound wave generator 1 and reflected by the sound wave surface A (specifically, the coarse and dense boundary surface generated in the atmosphere by the sound wave) of the sound wave traveling in the sky. The signal is detected by the radar receiver 12. Further, the received signal is input to the frequency shift amount measuring device 13, the frequency shift amount (Doppler shift) due to the Doppler effect is detected, and then the sound wave transmitted from the sound wave generator 1 in the observed airspace toward the sky is transmitted. Measure the speed of sound.

Then, the processing device 3 inputs the sound velocity data measured by the Doppler radar 2 and calculates the air temperature in the observed airspace by utilizing the property that the propagation velocity of the sound wave changes depending on the temperature of the medium. The processing device 3 typically comprises a computer. The processing device 3 can control the switching means 6 to control the timing of transmitting sound waves, input various initial data, and output the measurement result.

Normally, the Doppler radar 2 has a ranging function. For example, the exploration radio wave transmitted from the transmitting antenna 9 is reflected on the sound wave surface A, and the distance to the sound wave surface A can be calculated from the time difference until the reflected radio wave is received by the receiving antenna 10. In this way, the temperature altitude distribution in the sky can be measured by the lath radar according to the present embodiment.

As shown in FIGS. 3 and 4, the sound wave generation unit 40 according to the present embodiment includes a parametric speaker 4, a first reflector 21 inclinedly arranged under the parametric speaker 4, and a first reflector 21. The second reflector 22 is provided so as to be inclined at a position facing the above. Specifically, the parametric speaker 4 is installed on a gantry 41 provided above the first reflector 21 so as to output sound waves downward. The direction of the parametric speaker 4 in the present embodiment is set downward toward the first reflector 21, but if the arrangement is such that sound waves are output downward, the parametric speaker 4 is installed slightly diagonally. There is no problem.

The parametric speaker 4 includes a piezoelectric element that vibrates air by applying a voltage and vibrating it at a predetermined frequency, and is formed in a rectangular parallelepiped shape. The parametric speaker 4 can have a sharp directivity by using an ultrasonic wave as a part of the sound wave to be output. In this embodiment, the parametric speaker 4 is manufactured by Switch Science (registered trademark). Further, the sound pressure of the ultrasonic wave output by the parametric speaker 4 is 100db or more, and the number of piezoelectric elements is 5,000 or more and 20,000 or less.

As shown in FIGS. 3 and 4, the parametric speaker 4 is supported by a gantry 41 straddling the upper part of the first reflector 21. The gantry 41 is made of a steel frame made of H steel or the like, or an aluminum frame.

The first reflector 21 and the second reflector 22 are supported in an inclined state by the first support member 23 and the second support member 24. The first support member 23 and the second support member 24 are made of a steel frame or an aluminum frame, similarly to the gantry 41. The first reflecting surface 21a and the second reflecting surface 22a are formed on the surfaces of the first reflecting plate 21 and the second reflecting plate 22 facing each other, respectively.

In the present embodiment, the first reflector 21 and the second reflector 22 are flat concrete plates having a vertical dimension of 1 to 3 m, a horizontal dimension of 1 to 3 m, and a thickness of 20 mm or more. .. In the present embodiment, the first reflector 21 and the second reflector 22 are square plate-shaped members, but the first reflector 21 and the second reflector 22 may be rectangular. As the material of the first reflector 21 and the second reflector 22, hard concrete, foam concrete, concrete block, FPR, resin plate, iron plate, aluminum plate, stainless gold storage plate and the like can be adopted. However, from the viewpoint of reducing sound leakage to the back side of the plate, the first reflector 21 and the second reflector 22 are preferably formed of hard concrete, foam concrete, or mortar.

When the parametric speaker 4 outputs a sound wave in the sound wave generation unit 40 configured as described above, the output sound wave is the first reflection surface 21a and the second reflection of the first reflection plate 21 as shown by the arrow X in FIG. After being reflected twice in order by the second reflecting surface 22a of the plate 22, the wave is transmitted toward the sky.

As described above, according to the sound wave generator 1 for the lath radar according to the present embodiment, the parametric speaker 4 is installed in the sound wave generation unit 40 so as to output the sound wave downward. This makes it possible to prevent the piezoelectric element provided in the parametric speaker 4 from getting wet when it rains or snows.

Further, in the present embodiment, as shown by the arrow X in FIG. 5, the sound wave output from the parametric speaker 4 is reflected twice by the first reflector 21 and the second reflector 22 and then sent to the sky. It's waving. As a result, the reflected sound can be prevented from hitting the parametric speaker 4, and the sound wave can be appropriately transmitted to the sky. Further, it is possible to suppress sound leakage due to the sound wave reflected by the parametric speaker 4 propagating to the surroundings.

In the present embodiment, a concrete plate is adopted as the first reflector 21 and the second reflector 22, but the first reflector 21a and the second reflector 22a in the first reflector 21 and the second reflector 22 are used. Surface treatment such as smoothing or coating with mortar may be performed. Further, a sound absorbing material may be provided on the back surfaces of the first reflector 21 and the second reflector 22.

Further, the shapes of the first reflector 21 and the second reflector 22 are not limited to a flat surface, and may be a curved surface. However, from the viewpoint of ease of molding of the first reflector 21 and the second reflector 22, it is preferable to mold the first reflector 21 and the second reflector 22 with concrete. From the viewpoint of preventing sound leakage caused by the sound that the reflected sound hits the parametric speaker 4 spreading in the horizontal direction, it is preferable to form the first reflector 21 and the second reflector 22 with a curved plate.

In the sound wave generating unit 40 according to the present embodiment, the sound wave output from the parametric speaker 4 is reflected by the first reflecting plate 21 and the second reflecting plate 22 and then transmitted vertically upward as shown in FIG. Ru. As a result, the direction of the radio wave transmitted by the Doppler radar 2 and the direction of the sound wave can be superimposed, so that the accuracy of the sound velocity measurement by the Doppler radar 2 and the accuracy of the calculation of the temperature in the observed airspace can be improved. ..

Further, in the sound wave generation unit 40, the angle formed by the first reflector 21 and the second reflector 22 is set to be about 90 degrees. As a result, as shown in FIGS. 3 to 5, the parametric speaker 4 is simply installed in a direction in which the sound wave is output substantially vertically downward, and the sound wave reflected by the first reflecting plate 21 and the second reflecting plate 22 is vertically upward. It is possible to send waves to. That is, it is possible to facilitate the installation method of the parametric speaker 4 for transmitting the sound wave reflected by the first reflector 21 and the second reflector 22 vertically upward.

Further, in the sound wave generating unit 40, the inclination angle of the first reflector 21 and the second reflector 22 from the horizontal plane is between 40 degrees and 50 degrees (both 45 degrees in this embodiment) as shown in FIG. It is arranged so as to be. As a result, the distance between the sound wave output from the parametric speaker 4 before hitting the first reflector 21 and the sound wave transmitted to the sky after hitting the second reflector 22 can be increased. Therefore, it is difficult for the sound reflected by the second reflector 22 to hit the parametric speaker 4.

Further, in the sound wave generation unit 40, the parametric speaker 4 is installed in the region above the first reflector 21. In detail, as shown in FIG. 5, the parametric speaker 4 is located closer to the first reflector 21 than the virtual surface P perpendicular to the ground through the boundary line between the first reflector 21 and the second reflector 22. , It is installed so as not to intersect the virtual surface P. As described above, according to the present embodiment, by arranging the parametric speaker 4 retracted from the area above the second reflector 22, the sound reflected by the second reflector 22 is less likely to hit the parametric speaker 4. There is.

Next, with reference to FIG. 6, the experimental conditions of the first experiment regarding sound leakage in the sound wave generating unit 40 performed by the applicant of this patent application will be described. As shown in FIGS. 6A and 6B, in this experiment, an experimental sound wave generator 40 including the first reflector 21E and the second reflector 22E was prepared. The first reflector 21E and the second reflector 22E are made of a flat concrete plate having a length of 1.8 m, a width of 1.8 m, and a thickness of 50 mm.

In this experiment, as shown in FIG. 6A, the parametric speaker 4A installed at a position close to the first reflector 21E of the sound wave generating unit 40 and the parametric speaker 4B installed at a position away from the first reflector 21E. The effect of the sound wave on the surrounding environment was measured by transmitting sound waves in each of the above and measuring the volume with the noise meters M1 to M5 arranged around the sound wave generating unit 40. As the parametric speakers 4A and 4B in this experiment, those having 735 piezoelectric elements were used.

As shown in FIGS. 6 (a) and 6 (b), the sound level meters in this experiment include the first sound level meter M1 arranged above the second reflector 22E and the back side (second reflector 22E) of the first reflector 21E. The second sound level meter M2 arranged on the opposite side), the third sound level meter M3 arranged on the back side of the second reflecting plate 22E (the side opposite to the first reflecting plate 21E), and the first reflecting plate from the second reflecting plate 22E. Five sound level meters M4 and a fifth sound level meter M5, which were arranged at positions displaced in the boundary line direction between 21 and the second reflector 22, were used. As each sound level meter, a normal sound level meter "NL-42K" manufactured by Rion Co., Ltd. (registered trademark) was used.

In the first experiment, the measurement result of the first sound level meter M1 was 104.5db (A) for the parametric speaker 4A and 104.0db (A) for the parametric speaker 4B. As described above, regarding the first sound level meter M1, no significant difference was observed between the parametric speaker 4A and the parametric speaker 4B. On the other hand, the measurement results of the second to fifth sound level meters M2 to M5 are 43.1db (A), 56.7db (A), 48.5db (A), and 48.7db (A) in order with the parametric speaker 4A. There were 50.0db (A), 58.4db (A), 49.1db (A), and 49.1db (A) in the parametric speaker 4B. As described above, regarding the second to fifth sound level meters M2 to M5, the most measured value among the parametric speaker 4B is higher than the largest value among the measured values of the parametric speaker 4A, 56.7db (A). The larger value, 58.4db (A), was larger.

Further, with reference to FIG. 7, the experimental conditions of the second experiment regarding sound leakage in the sound wave generating unit 40 performed by the applicant of this patent application will be described. As shown in FIGS. 7 (a) and 7 (b), in this experiment, only the second reflector 22E was used.

In this experiment, as shown in FIG. 7A, the parametric speaker 4C installed at a position close to the second reflector 22E and the parametric speaker 4D installed at a position away from the second reflector 22E, respectively. The effect of the sound wave on the surrounding environment was measured by transmitting the sound wave with the speaker and measuring the volume with the noise meters M6 to M10 arranged around the second reflecting plate 22E. As the parametric speakers 4C and 4D in this experiment, the same ones as the parametric speakers 4A and 4B were used.

As shown in FIGS. 7A and 7B, the sound level meters in this experiment are the sixth sound level meter M6 arranged above the second reflector 22E, and the back side of the parametric speakers 4C / 4D (with the second reflector 22E). The seventh sound level meter M7 placed on the opposite side), the eighth sound level meter M8 placed on the back side of the second reflector 22E (the side opposite to the parametric speakers 4C / 4D), and the second reflector 22E, respectively. Five of the arranged 9th sound level meter M9 and 10th sound level meter M10 were used. As each sound level meter, a normal sound level meter "NL-42K" manufactured by Rion Co., Ltd. (registered trademark) was used.

In the second experiment, the measurement result of the sixth sound level meter M6 was 104.4db (A) for the parametric speaker 4C and 104.8db (A) for the parametric speaker 4D. As described above, regarding the sixth sound level meter M6, no significant difference was observed between the parametric speaker 4C and the parametric speaker 4D. On the other hand, the measurement results of the 7th to 10th sound level meters M7 to M10 are 52.8db (A), 54.4db (A), 47.0db (A), and 49.6db (A) in order with the parametric speaker 4C. There were 46.9db (A), 62.6db (A), 50.9db (A), and 48.2db (A) in the parametric speaker 4D. As described above, the 7th to 10th sound level meters M7 to M10 are the most measured values of the parametric speaker 4D than the largest value of 54.4db (A) among the measured values of the parametric speaker 4C. The larger value, 62.6db (A), was larger.

As described above, in both the first experiment and the second experiment, when the parametric speaker 4 is installed away from the first reflector 21E or the second reflector 22E (parametric speaker 4B / 4D), the first reflector As a result, sound leakage becomes larger than when it is installed close to 21E or the second reflector 22E (parametric speakers 4A / 4C). It is considered that this is because the sound wave output from the parametric speaker 4 travels while spreading (widening).

From the results of the first experiment described above, it is preferable that the parametric speaker 4 is installed at a position close to the first reflector 21 in the sound wave generating unit 40. For example, in the parametric speaker 4, the vertical distance from the center to the first reflector 21 (L1 in FIG. 5) is the parametric speaker 4 in the slope direction of the first reflector 21 (horizontal direction in FIG. 5). It is preferable to install it at a position smaller than the horizontal length (L2 in FIG. 5).

Further, from the result of the second experiment, in the sound wave generating unit 40, the position where the sound wave transmitted by the parametric speaker 4 is reflected by the first reflecting plate 21 is preferably close to the second reflecting plate 22. Therefore, the parametric speaker 4 has a horizontal distance between the central portion and the virtual surface P which is the boundary surface between the region above the first reflector 21 and the region above the second reflector 22 (in FIG. 5). L3) is preferably installed at a position smaller than the horizontal length L2 of the parametric speaker 4 in the slope direction of the first reflector 21.

As the sound wave generator 1 used in the actual lath radar, the configuration in which the parametric speaker 4 is arranged at the position of the parametric speaker 4C only on the second reflector 22 as in this experiment is provided in the parametric speaker 4 during rainfall or snowfall. It is not practical because there is a high possibility that the generated piezoelectric element will get wet. At this time, even if the parametric speaker 4 is provided with a roof, it is not appropriate because sound waves hit the roof and sound leakage occurs. Further, the configuration in which the parametric speaker 4 is arranged at the position of the parametric speaker 4D only on the second reflector 22 as in this experiment is not appropriate because the sound leakage becomes large as in the above experimental result.

Next, the sound wave generating unit 140 according to the second embodiment will be described with reference to FIGS. 8 and 9. The sound wave generation unit 140 according to the present embodiment is different from the sound wave generation unit 40 according to the first embodiment in that a secondary reflector 31 is provided at the upper end of the second reflector 22. Regarding the sound wave generating unit 140 according to the present embodiment, detailed description of the same configuration as the sound wave generating unit 40 according to the first embodiment will be omitted, and the secondary reflector 31 will be mainly described.

As shown in FIG. 8, the secondary reflector 31 is supported by a support member (not shown) in a state of being continuous with the upper end of the second reflector 22 and being inclined with respect to the second reflector 22. The secondary reflector 31 is formed with the same length as the second reflector 22 in the horizontal direction, and a flat concrete plate having a vertical dimension of 0.5 to 1 m and a thickness of 20 mm or more is adopted. .. As the material of the secondary reflector 31, hard concrete, foam concrete, concrete block, FPR, resin plate, iron plate, aluminum plate, stainless metal storage plate, etc. are adopted as the material of the first reflector 21 and the second reflector 22. can do. However, from the viewpoint of reducing sound leakage to the back side of the plate, the secondary reflector 31 is preferably formed of hard concrete or mortar.

When the parametric speaker 4 outputs a sound wave in the sound wave generation unit 140 configured as described above, a part of the output sound wave is reflected by the secondary reflector 31 and then directed toward the sky as shown by the arrow Y in FIG. Is sent.

Next, with reference to FIG. 10, the experimental result of the third experiment regarding sound leakage in the sound wave generating unit 140 according to the present embodiment, which was performed by the applicant of the present patent application, will be described. In this experiment, the sound wave generation unit 140 having a variable angle from the horizontal plane of the secondary reflector 31 was configured under the same conditions as in the first experiment. Then, the angle of the secondary reflector 31 is changed, and the volume is measured by the second sound level meter M2 to the fifth sound level meter M5 arranged around the sound wave generating unit 140 in the same manner as in the first experiment. The relationship between the angle of the reflector 31 and the effect of sound waves on the surrounding environment was investigated.

As shown in FIG. 10, as a result of drawing an approximate curve of the maximum value of the noise level of each sound level meter M2 to M5 with a quadratic curve, the angle of the quadratic reflector 31 from the horizontal plane became the minimum near 70 degrees. From this experimental result, it is preferable to arrange the secondary reflector 31 so that the angle between the secondary reflector 31 and the horizontal plane is 65 to 70 degrees. As a result, sound leakage from the sound wave generation unit 140 of the sound wave transmitted by the parametric speaker 4 can be minimized, and the sound wave can be appropriately transmitted to the sky.

Also in this embodiment, the surface of the secondary reflector 31 may be subjected to surface treatment such as smoothing or coating with mortar. Further, a sound absorbing material may be provided on the back surface of the secondary reflector 31.

In the sound wave generation unit 140 according to the present embodiment, a part of the sound wave output from the parametric speaker 4 is reflected by the secondary reflector 31 and then transmitted upward as shown in FIG. As a result, the direction of the radio wave transmitted by the Doppler radar 2 and the direction of the sound wave can be superimposed, so that the accuracy of the sound velocity measurement by the Doppler radar 2 and the accuracy of the calculation of the temperature in the observed airspace can be further improved. can.

1 Sound wave generator 2 Doppler radar
3 Processing equipment 4 Parametric speaker
4A-4D parametric speaker
5 oscillator 6 switching means
7 thyristor 8 amplifier
9 Transmit antenna 10 Receive antenna
11 Radar transmitter 12 Radar receiver
13 Frequency shift amount measuring instrument 21 First reflector
21a First reflector 21E First reflector
22 Second reflector 22a Second reflector
22E Second reflector 23 First support member
24 Second support member 31 Secondary reflector
41 gantry 42 control box
A sound wave surface D exploration radio wave
P Virtual surface R Reflected radio wave
M1 to M10 sound level meter X arrow
Y arrow

Claims (9)

For lath radar, which sends sound waves and radio waves toward the sky, measures the speed of sound in the observed airspace from the frequency shift amount due to the Doppler effect of the radio waves reflected by the sound wave surface, and calculates the temperature in the observed airspace from the measured sound velocity. Sound wave generator
Sound waves are applied to the first reflector arranged at an angle, the second reflector arranged at an angle facing the first reflector, and the gantry provided above the first reflector. Equipped with a parametric speaker installed in the direction of outputting downward,
The sound wave output from the parametric speaker is reflected by the first reflector and then sent toward the second reflector.
The sound wave transmitted from the first reflector toward the second reflector is reflected by the second reflector and then transmitted toward the sky.
A sound wave generator for a lath radar, wherein a secondary reflector that is inclined with respect to the second reflector is provided at an end of the second reflector on the opposite side of the first reflector. The sound wave generator for a lath radar according to claim 1 , wherein the sound wave output from the parametric speaker is reflected by the first reflector and the second reflector and then transmitted vertically upward. The sound wave generator for a lath radar according to claim 1 or 2 , wherein the parametric speaker is installed so as to output sound waves vertically downward. The sound wave generator for a lath radar according to claim 3 , wherein the first reflector and the second reflector are arranged so as to be inclined at an angle between 40 degrees and 50 degrees from a horizontal plane. The sound wave generator for a lath radar according to claim 4 , wherein the parametric speaker is installed in an area above the first reflector. According to claim 5 , the parametric speaker is installed at a position where the vertical distance from the center to the first reflector is smaller than the horizontal length of the parametric speaker in the slope direction of the first reflector. The sound generator for the described lath radar. In the parametric speaker, the horizontal distance between the central portion and the boundary surface between the region above the first reflector and the region above the second reflector is the horizontal distance in the slope direction of the first reflector. The sound wave generator for a lath radar according to claim 6 , which is installed at a position smaller than the horizontal length of the parametric speaker. The sound wave generator for a lath radar according to any one of claims 1 to 7, wherein the first reflector and the second reflector are formed of hard concrete, foamed concrete, or mortar. The sound wave generator according to any one of claims 1 to 8 .
Doppler that transmits radio waves toward the sky, receives reflected radio waves from the sound wave surface of the sound waves transmitted toward the sky from the sound wave generator, and measures the speed of sound in the observed airspace from the frequency shift amount due to the Doppler effect. With radar,
A lath radar comprising a processing device for calculating the air temperature in the observed airspace from the speed of sound measured by the Doppler radar.

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