JP2008157765A - Weather measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a weather measuring device having a simple configuration, capable of not only performing accurate measurement relative to rainfall but also collecting correlatively various information on the weather of rain such as the size of rain droplets or dropping speed of the rain droplets, and measuring the weather such as snow or fog. <P>SOLUTION: This device is equipped with a light source 6; a collimating lens 7 for collimating light emitted from the light source 6 into parallel light L2 proceeding to a prescribed direction C; a condensing lens 8 arranged separately from the collimating lens 7 at a fixed distance in the prescribed direction C; and an image sensor 4 for receiving light from the condensing lens 8, and outputting image data of rain droplets, snow particles, fog particles or the like in the air passing between the lenses. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a meteorological measurement apparatus that can be suitably used for measuring rainfall and the like.

  As shown in Patent Document 1, a conventional rain gauge is a tipping type rain gauge having a pair of falls that alternately fall, and generates a pulse from the pulse generator every time it falls. The rain is measured.

However, the falling type rain gauge falls as a pair, but after receiving a predetermined amount of rainwater from the rainwater measurement receiving funnel, it takes almost one second until the start of the overturning and the end. As a result, after a predetermined amount of rainwater has been received, after the start of the fall, the adjacent falls, but in the process of reversing to the position where it can receive the rainwater in the rainwater receiving funnel, In order to fall during a fall, rainwater from the rainwater measurement receiving funnel continues to flow for several seconds. The pulse generator transmits the pulse signal having the predetermined amount of rain every time the vehicle falls, so that the amount of rain for a few seconds is ignored from the actual amount of rain. For this reason, there is a problem that a minus error occurs in the rainfall measurement value due to the above result, particularly in the case of high rainfall.
In addition, since it is not possible to measure the amount of rainfall that falls below the size that falls, if the accumulated rainfall falls below, the raindrops will evaporate, resulting in an error.
A bigger problem is that the capture rate is reduced by the influence of wind. When rain falls on the side due to strong winds, it falls into a box shape, so if it falls, rain is not supplemented, and a negative error still occurs in the rainfall measurement.

In addition, the falling rain gauge can only be used for rainfall measurement, and it cannot collect various information related to the weather such as the size of raindrops and the falling speed of raindrops. Other weather measurements are also difficult.
Japanese Patent Publication No. 9-243758

  The present invention has been made in view of such problems, and not only enables more accurate measurement of the rainfall, but also provides various information related to the rainy weather such as the size of raindrops and the falling speed of raindrops. The main objective of the present invention is to provide a weather measuring device with a simple configuration that can be collected in association with each other and that can also measure weather such as snow and fog.

  That is, the meteorological measurement apparatus according to the present invention includes a light source, a collimating lens that converts the light emitted from the light source into parallel light that travels in a predetermined direction, and a collection unit that is disposed at a predetermined distance from the collimating lens in the predetermined direction. Floating due to weather phenomena such as raindrops, snowdrops, mist droplets (hereinafter referred to as raindrops) in the air that receives light from the optical lens and the condenser lens and passes between the lenses And an image sensor that outputs image data of a fallen object.

  If this is the case, the contours (shadows) of raindrops, etc., formed by irradiating parallel light are measured, so no matter where the raindrops pass through the parallel light, the contours of the raindrops at that time will be shown. The image sensor can reliably detect the size. Accordingly, it is possible to accurately measure the volume of the entire raindrop and the rainfall calculated from the shadow portion of the image data. In addition, if the sampling time of the image data is set short, it is possible to easily calculate the accurate rainfall continuously.

  In addition, it is possible to detect the size and shape of raindrops, the falling speed, etc. at the same time as the rainfall, so it is possible to measure the weather associated with them, and to analyze new facts that have not been clarified so far It is thought that it becomes.

  In addition, since parallel light is used as described above, theoretically, the distance between the lenses may be set to an appropriate value according to the object to be measured and its amount, thereby improving the measurement accuracy. There is no reduction.

  Furthermore, since the basic components necessary for the present invention are only the light source, the pair of lenses, the image sensor, and the casing (housing) for supporting and housing them, the configuration is very simple and the cost can be reduced. In addition, it does not impair the advantage that it can be installed anywhere outdoors.

  In order to eliminate as much as possible adverse effects on the measurement due to stray light or the like, the light source, the collimating lens, the condensing lens, and the image sensor are further provided in a single casing, and the parallelism in the casing is included. It is preferable that an introduction port for raindrops or the like is opened immediately above the light.

  In this case, if a rebound prevention mechanism for preventing the rebounding of raindrops and the like that have fallen is provided at the lower end of the casing, the influence of the rebound on measurement can be prevented. Specific examples of the bounce prevention mechanism include a tapered structure that gradually decreases in cross-sectional area as it goes downward, and has a outlet for raindrops at its lower end, a porous body that absorbs moisture, and its The thing provided with the outlets for raindrops etc. provided below can be mentioned.

  As a configuration that is not easily affected by the wind, a light emitting system housing that holds the light source and the collimating lens inside is provided separately from the light emitting system housing, and the light collecting lens and the image sensor are held inside the light emitting system housing. It is desirable to further include a light receiving system casing and a support body that connects and holds the light emitting system casing and the light receiving system casing so that their relative positional relationship does not change.

  As a specific aspect of the support, the support includes an arm member that holds the light emitting system housing and the light receiving system housing at each end, and a base member that hangs down from the center of the arm member. Can be mentioned.

  Even if a strong wind blows and raindrops flow, the raindrops cross the parallel light at right angles to ensure measurement accuracy. In order to prevent entry into the interior as much as possible, the arm member is supported by the base member so as to be able to turn horizontally, and the wind direction and the parallel light are orthogonal to each other in plan view. An angle adjusting mechanism for adjusting the turning angle of the arm member may be provided.

  As an angle adjusting mechanism having a simple configuration that does not require power, a mechanism in which a wing member extending in one direction is attached to a required portion of the arm member so as to be orthogonal to the parallel light in a plan view. In addition, for example, a configuration in which an anemometer is provided separately and the turning angle of the arm member is automatically adjusted by a computer or the like according to the wind direction obtained from the anemometer may be used.

  It is preferable that the light source is closer to the point light source because the parallelism of parallel light can be easily improved and the outline of raindrops and the like can be obtained more clearly. In addition, it is desirable to use an LED as the light source in consideration of the life, quick response, efficiency, cost, and the like.

  Obtaining clearer outlines such as raindrops can also be achieved by devising a light receiving system. That is, an aperture mechanism having a pinhole may be provided at the focal position of the condenser lens. This also has the advantage of increasing the degree of freedom of the types of light sources that can be used.

  When raindrops and the like are arranged in the same direction as the parallel light, they overlap on the image data, which causes a measurement error. In order to avoid this, the second parallel light irradiated in a direction different from the parallel light may be formed, and image data such as raindrops crossing the second parallel light may be output. . This is because, by comparing each image data, a measurement error can be avoided by detecting a raindrop or the like that is superposed.

  By the way, if the image data is always recorded, the amount of recording data is increased. However, in order to record image data only when it rains, even if it uses a detection means that detects the start and end of rain, there is actually a small amount of rain that cannot be detected by the detection means. It may have begun to descend before that, and the measurement is not accurate. In order to solve such problems all at once, the output image data is always recorded while being overwritten in a temporary memory of a certain capacity, and when the detection means for detecting raindrops or the like detects raindrops for the first time, As a recording start trigger signal, it is desirable to provide an image data recording mechanism for recording image data from a predetermined time before to a permanent memory. As the recording end trigger, a predetermined time after the rain is no longer detected by the detecting means may be set.

  Examples of what can be measured using the present invention include an amount related to the volume of raindrops and the like. “Amount related to volume” refers to the volume of raindrops and the amount obtained therefrom, that is, the amount of rainfall, the amount of snowfall, the density of fog, and the like.

  Other things that can be measured include the moving speed of raindrops (for example, the falling speed). For this purpose, it is only necessary to further provide a speed calculation unit that acquires a plurality of the image data at regular time intervals and calculates an amount related to the moving speed of raindrops or the like from changes in the image data. If limited to raindrops, the moving speed can also be calculated from the contour shape. From this speed information, the amount of rainfall and the amount of snowfall can also be obtained.

Moreover, this weather measuring apparatus can also be used as a visibility meter. For this purpose, a visibility distance calculation unit that calculates a visibility distance based on the image data and a substantial length for allowing raindrops of parallel light to pass through may be further provided.
It is further preferable that the image processing apparatus further includes a current weather calculation unit that calculates the current weather based on the image data within a certain period from the past to the present and the calculated visibility distance, rainfall amount, snowfall amount, and the like.

  In order to achieve compactness, it is preferable that each lens is a Fresnel lens. In this case, if the surfaces facing each other are arranged so as to be lens surfaces and the surfaces facing each other are flat, the contour can be clearly obtained.

  According to the present invention configured as described above, more accurate continuous measurement can be performed regarding the rainfall, and various information related to the weather such as rain, such as the size of raindrops and the falling speed of raindrops, can be collected in association with each other. . Further, not only rain, but also other weather such as snow and fog can be measured, and it can be used as a visibility meter.

  Furthermore, basically, the light source, the pair of lenses, the image sensor, and the casing (housing) for supporting and housing them can be realized with a very simple configuration, so that the cost can be reduced and the conventional method can be realized. Thus, the advantage that it can be installed anywhere outdoors is not impaired.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  <First Embodiment>

  The meteorological measurement apparatus 1 according to the present embodiment measures the form (particularly the contour) of the raindrops 2 falling in the air. First, the basic measurement principle of the meteorological measurement apparatus 1 is only the basic configuration. This will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the meteorological measurement apparatus 1 includes a light emitting system mechanism P1 including a light source 6 and a collimating lens 7 that converts the light L1 emitted from the light source 6 into parallel light L2 that travels in a predetermined direction C. A light receiving system mechanism comprising a condenser lens 8 arranged at a predetermined distance from the collimating lens 7 in the predetermined direction C, and an image sensor 4 that receives the light L3 that has passed through the condenser lens 8 and outputs image data. And P2.

  In such a configuration, the raindrop 2 falls on the optical path portion of the parallel light L2 and crosses it, but at that time, the light is refracted or reflected and scattered in the raindrop 2 portion and does not become parallel light. Does not image on top. That is, as shown in an example of the image data in FIG. 3, only the raindrop 2 portion becomes a black shadow. And the shape of this shadow shows the outline shape of the raindrops 2, which will be in the position close to or far from the image sensor regardless of where each raindrop 2 is in the parallel light. However, it represents the ratio of the actual size of each raindrop 2 as it is. Therefore, as long as the magnification of the image data is known, by processing this image data, it is possible to accurately calculate the amount of rain, the magnitude of raindrops, the falling speed of raindrops, and the like, as will be described later.

  Second Embodiment

  Next, a more specific embodiment will be described below. In the second embodiment, members corresponding to those in the first embodiment are denoted by the same reference numerals.

  In addition to the light emitting system mechanism P1 and the light receiving system mechanism P2, the meteorological measurement apparatus 1 according to this embodiment includes a light emitting system casing Q1 and a light receiving system casing Q2 that house them, respectively, as shown in FIGS. Then, various information is calculated from the support 3 that holds and connects the light emitting system casing Q1 and the light receiving system casing Q2 so that the relative positional relationship does not change, and the image data output from the area image sensor 4. And an information processing device 5.

  The light emitting system casing Q1 has, for example, a cylindrical shape with one end opened. The parallelizing lens 7 is attached to the back side by a certain distance from the opening Q1a, and the LED 6 serving as a light source on the lens optical axis at the back. Is arranged. Like the light emitting system housing Q1, the light receiving system housing Q2 has a cylindrical shape with one end opened. A condensing lens 8 is mounted on the back side by a certain distance from the opening Q2a, and the lens light in the back is further provided. On the shaft, an image sensor 4 such as a CCD is disposed. An optical diaphragm mechanism (not shown) is provided between the condenser lens 8 and the image sensor 4. This diaphragm mechanism is formed by arranging a pinhole at the focal position of the condenser lens 8. Here, as the collimating lens and the condenser lens, as illustrated in the first embodiment (FIGS. 1 and 2), a Fresnel lens is used to make the optical axis direction compact, and surfaces facing each other are used as lenses. The planes and the planes facing each other are arranged to be flat. In addition, the “certain distance” mentioned above is a distance where there is almost no rain and snow from the opening to the lens behind it even when the wind blows, and there is almost no influence on the measurement by them. It is.

  The support 3 includes an arm member 31 having a substantially U shape, and a base member 32 that is suspended from the center of the arm member 31 and is installed on the ground or the like. The arm member 31 is composed of a horizontal bar 311 and vertical bars 312 erected from the end portions thereof. At the upper end of each vertical bar 312, the light emitting system casing Q1 and the light receiving system casing Q2 have their openings Q1a. , Q2a are attached to each other with a certain distance therebetween. In this embodiment, the light emitting system mechanism Q1 and the light receiving system mechanism P2 can be accurately aligned with respect to the arm member 31 of the light emitting system casing Q1 and the light receiving system casing Q2 so that the optical axes can be accurately matched. The mounting angle can be finely adjusted in the vertical and horizontal directions. The base member 32 has, for example, a cylindrical shape, and supports the arm member 31 so that the arm member 31 can turn horizontally at an upper end portion thereof. And the power supply to LED6, the information processing mechanism 5 mentioned later, etc. are accommodated in the inside.

  Furthermore, in this embodiment, the wing member 33 is attached to the central portion of the horizontal bar 311 in the arm member 31. The wing member 33 is attached so that the direction in which the wing extends is perpendicular to the extending direction of the horizontal bar, that is, the traveling direction of the parallel light L2.

  As shown in FIG. 7, the information processing apparatus 5 is, for example, a general-purpose computer including a CPU 101, a memory 102, an I / O channel 103, and the like, and is connected to a display 104, an input unit 105 such as a mouse and a keyboard, and the like. .

  Then, by installing a predetermined program in the information processing apparatus 5 and cooperating the CPU 101 and peripheral devices based on the program, the information processing apparatus 5 receives the image data from the area image sensor 4, Functions as an image processing unit 51 that performs contrast processing on the image data and outputs the image data to a display, a volume calculation unit 52 that calculates an amount related to the volume of the raindrop 2 based on the image data processed by the image processing unit 51, and the like (A functional block diagram is shown in FIG. 8).

  More specifically, in the image data initially transmitted from the area image sensor 4, the portion where the raindrop 2 exists and the light is blocked is dark and the other portions are bright. In order to make this more apparent, for example, a black and white binarization process is performed so that the portion where the raindrop 2 is present is black and the other portions are white. An example of the image data displayed on the display is shown in FIG.

  The volume calculation unit 52 calculates the area of the black region in the image data after the image processing, and applies a proportional constant thereto, thereby being in the parallel optical path (more precisely, within the effective length between the openings Q1a and Q2a). The total volume of raindrops 2 is calculated. This is because the raindrops 2 are represented as black shadows, and even if each raindrop 2 is far from or close to the area image sensor 4, the shadow is due to the irradiation of the parallel light L2. This is because the area appears at the same magnification with respect to the longitudinal section of each raindrop 2. In calculating the area of the black shadow area, the area of one shadow may be calculated and multiplied by the counted number.

  When the density of the raindrops 2 increases to some extent, the raindrops 2 overlap with each other when viewed from the optical axis direction C (the shades overlap), and the proportional relationship between the area of the shadow area and the volume of the raindrops 2 is lost due to the influence. Come. For this reason, the volume calculation method of applying the proportionality constant described above causes measurement errors. To prevent this, the relationship between the area of the black region and the volume of the raindrop 2 is obtained in advance for calibration. It may be expressed by a curve or the like, and the volume may be obtained from the area of the black region using the relationship.

  The speed calculation unit 53 calculates the falling speed or moving speed of the raindrop 2 from the change of each image data sampled at a constant time interval. Note that the contour shape of the raindrop 2 changes according to the size and speed. That is, the larger the speed, the more the shape changes from a circular shape to a long and narrow shape. Therefore, the drop speed (or moving speed) of the raindrop 2 is determined based on the contour shape information. You may make it calculate.

  In the present embodiment, the rain amount calculation unit 54 that calculates the rain amount from the volume of the rain drop 2 thus obtained and the moving speed thereof, and the substantially the same for allowing the image data and parallel light rain drops to pass through. And a visibility distance calculation unit 55 that calculates the visibility distance based on the effective length (effective length).

  Next, the operation of the weather measurement apparatus 1 having such a configuration will be briefly described below.

  The arm member 31 is automatically adjusted by the action of the wing member 33 so that the arm member 31 is always perpendicular to the wind direction in plan view. That is, the wind always blows from the direction orthogonal to the parallel light L2.

  Under such circumstances, the image data and each information obtained from it (rain drop speed, rain amount, visibility distance) are always stored in a small capacity temporary storage area set in the memory 102 for a certain period of time from the present to the past. It is saved while being overwritten one after another so that it remains.

  Here, when it starts to rain, a detector provided separately (for example, detecting the presence or absence of rain by changing the resistance of an electric wire placed on the ground, not shown) detects the detection signal to the information processing device 5. Is output.

  The information processing device 5 receives this as a recording trigger signal, and not only the image data acquired from the reception time point and each information associated therewith, but also stored in the temporary storage area for a certain period from the reception time point Previous image data or the like is also recorded in a permanent storage area set in the memory 102 or an external memory.

  Therefore, according to the meteorological measurement device 5 configured as described above, since the shadow of the raindrop 2 formed by irradiating the parallel light L2 is measured, no matter where the raindrop 2 is located, The outline (shadow) of the raindrop 2 can be reliably detected by the image sensor according to the size. Accordingly, the volume of the entire raindrop 2 can be easily and accurately calculated from the shadow portion of the image data, and an accurate rain amount can be continuously calculated by setting the sampling time of the image data short.

  In addition, in this embodiment, since the size and shape of the raindrop 2 and the falling speed are calculated simultaneously with the rainfall, it is possible to analyze new facts that have not been clarified so far by associating them with the rainfall. It is thought that it becomes.

  Furthermore, no matter what value the effective length of the parallel light L2 is set, the measurement accuracy is theoretically not affected, so the effective length is appropriately set to an optimum value according to the object to be measured and its amount. Can be easily done. For example, in this embodiment, the effective length of the parallel light L2 is set to a length that allows a plurality of raindrops 2 to pass.

  In addition, since the necessary basic components are only the LED 6, the pair of lenses 8, 9, the image sensor 4, and the support 3 for supporting and accommodating them, the configuration is very simple and the cost can be reduced. In addition, it does not impair the advantage that it can be installed anywhere outdoors.

  Further, the arm member 31 is swung by the wing member 33 so that the raindrop 2 always crosses the parallel light L2 at a right angle even when the wind blows, so that the measurement accuracy is ensured and the raindrop 2 is attached to each casing. Intrusion into the inside through the openings Q1a and Q2a of Q1 and Q2 can be suppressed as much as possible.

  Furthermore, when the raindrop detection means detects raindrops for the first time, the image data from the predetermined time before is recorded in the permanent storage area. Recording can be performed with a limited capacity.

  In the present embodiment, the wing member can have other modes using an anemometer or the like, and the shapes of the housing, the arm member, and the like can be variously modified.

  <Third Embodiment>

  The meteorological measurement apparatus 1 according to this embodiment has a light emitting system mechanism P1 and a light receiving system mechanism P2 inside as shown in FIGS. 9 and 10 instead of the separated casings Q1 and Q2 as in the second embodiment. A single casing R for housing is provided. In this embodiment, the same reference numerals are assigned to members corresponding to the first and second embodiments. In addition, since the operation function itself including the information processing apparatus 5 is the same as that of the second embodiment, different parts will be mainly described below, and description of the same parts may be omitted.

  The casing R in the meteorological measurement device 1 has a hollow box shape, and an introduction port R1 for introducing raindrops or the like is opened at the center of the top plate. The light emitting system mechanism P1 and the light receiving system mechanism P2 are respectively supported by the opposing standing walls of the casing R, and the parallel light L2 passes horizontally through the center of the casing R. The introduction port R1 is positioned immediately above the center of the parallel light L2. By the way, in this embodiment, the thickness of the introduction port R1 is set as thin as possible and the size is set smaller than the width direction dimension and the traveling direction dimension (optical axis direction dimension) of the parallel light L2, Thus, even if rain enters a little obliquely, the rain crosses the parallel light L2 without almost touching the inner surface of the introduction port R1.

  At the lower end of the casing R1, a rebound prevention mechanism R2 for preventing the raindrops 2 that have fallen from rebounding upward is provided. Specifically, the inner surface of the casing R is narrowed below the parallel light L2, and a tapered structure whose cross-sectional area gradually decreases as it goes downward is provided with a lead-out port R3 for raindrops or the like at its lower end. Yes.

  According to this embodiment, since the entire optical system including the parallel light L2 is accommodated in the casing R, adverse effects on measurement due to stray light from the outside can be eliminated as much as possible. Further, since the bounce prevention mechanism R2 is provided, the influence on the measurement due to the bounce of the raindrop 2 can be prevented.

  In addition, examples of the bounce prevention mechanism include a mechanism provided with a porous body that absorbs moisture and an outlet for raindrops provided below the porous body.

  <Other embodiments>

  When raindrops and the like are arranged in the same direction as the parallel light, they overlap on the image data and cause measurement errors. In order to avoid this, as shown in FIG. 11, the second parallel light L2 ′ irradiated in a direction different from the parallel light is formed, and image data such as raindrops crossing the second parallel light L2 ′ is obtained. May be configured to output the output. This is because, by comparing each image data, a measurement error can be avoided by detecting a raindrop or the like that is superposed. In FIG. 11, the light emitting system mechanism P1 and the light receiving system mechanism P2 are also provided in pairs. For example, the light source system P1 and the light receiving system mechanism P2 are separated by a half mirror using a common light source to generate parallel light and second parallel light. Different colors may be used.

In addition, the present invention is not limited to the measurement of raindrops, and can also measure weather phenomena such as snow and fog. For example, since the outline (shadow) of raindrops, etc., formed by irradiating parallel light is measured, the timing of changing from rain to snow, the mixing condition of rain and snow, etc. are calculated based on the outline information. It may be.
Furthermore, a current weather calculation unit that records the image data for the past several hours to several tens of hours and calculates the current weather from the plurality of image data and the calculated visibility distance, rainfall amount, snowfall amount, etc. Further, it may be provided.

  In addition, the present invention is not limited to the illustrated examples and embodiments, and various modifications can be made without departing from the gist of the present invention, such as appropriately combining each component.

1 is a schematic overall view showing a weather measurement device according to a first embodiment of the present invention. The typical perspective view which shows the weather measurement apparatus in the embodiment. The image illustration figure in the embodiment. The front view which shows the weather measurement apparatus in 2nd Embodiment of this invention. The side view which shows the weather measurement apparatus in the embodiment. The top view which shows the weather measurement apparatus in the embodiment. The typical equipment block diagram which shows the information processing apparatus in the embodiment. The internal functional block diagram of the information processing apparatus in the embodiment. The schematic longitudinal cross-sectional view which shows the internal structure of the weather measurement apparatus in 3rd Embodiment of this invention. The fragmentary perspective view which shows the weather measurement apparatus in the embodiment. The top view which shows the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Weather measuring device 2 ... Raindrop 3 ... Support body 31 ... Arm member 32 ... Base member R ... Casing 4 ... Area image sensor 52 ... Volume calculation part 53 ... Speed calculator 54 ... Rainfall calculator 55 ... Visibility distance calculator 6 ... Light source (LED)
7 ... Parallelizing lens 8 ... Condensing lens C ... Predetermined direction P1 ... Optical system mechanism P2 ... Light receiving system mechanism Q1 ... Optical system housing Q2 ... Light receiving system housing

Claims (20)

A light source;
A collimating lens that converts the light emitted from the light source into parallel light traveling in a predetermined direction;
A condenser lens arranged at a predetermined distance from the collimating lens in the predetermined direction;
An image sensor that receives light from the condensing lens and outputs image data of raindrops, snowdrops, mist, etc. (hereinafter referred to as raindrops) in the air passing between the lenses. A meteorological measurement device characterized by that. A casing that houses the light source, the collimating lens, the condenser lens, and the image sensor;
The meteorological measurement apparatus according to claim 1, wherein an introduction port for raindrops or the like is opened immediately above the parallel light in the casing.   The meteorological measurement device according to any one of claims 1 to 2, wherein a bounce prevention mechanism is provided at a lower end portion of the casing to prevent an upward splash of raindrops and the like that have fallen.   The meteorological measurement apparatus according to claim 3, wherein the rebound prevention mechanism includes a tapered structure that gradually decreases in cross-sectional area as it goes downward, and is provided with a lead-out port for raindrops or the like at a lower end thereof.   4. The meteorological measurement apparatus according to claim 3, wherein the rebound prevention mechanism includes a porous body that absorbs moisture and a lead-out port for raindrops provided below the porous body. A light emitting system housing that holds the light source and the collimating lens therein;
A light receiving system housing that is provided separately from the light emitting system housing and holds the condenser lens and the image sensor inside;
The meteorological measurement apparatus according to claim 1, further comprising: a support body that connects and holds the light emitting system housing and the light receiving system housing so that the relative positional relationship thereof does not change.   The weather according to claim 6, wherein the support includes an arm member that holds the light emitting system housing and the light receiving system housing at each end, and a base member that hangs down from the center of the arm member. measuring device. The base member supports the arm member so as to be horizontally rotatable;
The meteorological measurement apparatus according to claim 7, further comprising an angle adjustment mechanism that adjusts a turning angle of the arm member so that a wind direction and the parallel light are orthogonal to each other in plan view.   The meteorological measurement apparatus according to claim 8, wherein the angle adjusting mechanism is configured such that a wing member extending in one direction is attached to a required portion of the arm member so as to be orthogonal to the parallel light in a plan view.   The meteorological measurement apparatus according to claim 1, wherein an aperture mechanism having a pinhole is provided at a focal position of the condenser lens.   11. The meteorological measurement according to claim 1, wherein a second parallel light irradiated in a direction different from the parallel light is formed, and image data such as raindrops crossing the second parallel light is also output. apparatus.   An image data recording mechanism for recording the output image data is further provided, and when the image data recording mechanism receives a recording start trigger signal, the image data from a predetermined time before is recorded. The meteorological measurement apparatus according to claim 1.   The recording start trigger further includes raindrop detection means for detecting raindrops, etc., and the recording start trigger signal is output when the raindrop detection means detects raindrops for the first time. Item 12. A weather measurement device according to item 12.   The meteorological measurement apparatus according to any one of claims 1 to 13, wherein a substantial length of the parallel light for allowing raindrops or the like to pass therethrough is set to a length that allows a plurality of raindrops or the like to pass therethrough.   The meteorological measurement apparatus according to claim 1, further comprising a volume calculation unit that calculates an amount related to a volume of raindrops or the like based on the image data.   The weather measurement apparatus according to claim 1, further comprising a speed calculation unit that acquires a plurality of the image data at regular time intervals and calculates an amount related to a falling speed of raindrops or the like from changes in the image data.   The meteorological measurement apparatus according to claim 1, further comprising a speed calculation unit that calculates an amount related to a falling speed of the raindrops based on raindrop outline information obtained from the image data.   The meteorological measurement device according to any one of claims 1 to 17, further comprising a visibility distance calculation unit that calculates a visibility distance based on the image data and a substantial length for allowing raindrops of parallel light to pass through. .   The weather measurement apparatus according to claim 1, further comprising a current weather calculation unit that calculates a current weather based on the image data. The meteorological measurement apparatus according to any one of claims 1 to 19, wherein each of the lenses is a Fresnel lens, and a surface facing each other is a lens surface and a surface facing each other is a plane.