Meteorological observation lidar device

Abstract

The present invention comprises: a light source that generates laser light; a transmission / reception unit that selectively transmits laser light in a first direction, a second direction, and a third direction in the air and receives scattered light; and a calculation unit that calculates the wind direction, the wind speed, and the amount of water vapor in the air on the basis of interference light between the laser light and the scattered light. The calculation unit calculates the wind direction and the wind speed on the basis of an interference light generated by a first duration transmission in the first direction, an interference light generated by a second duration transmission in the second direction, and an interference light generated by a third duration transmission in the third direction, and calculates the amount of water vapor in the air on the basis of an interference light generated by a fourth duration transmission which is longer than the first duration, the second duration, and the third duration in the first direction, the second direction, or the third direction.

Description

Weather observation lidar equipment

[0001] The present disclosure relates to a meteorological observation lidar device that measures wind direction, wind speed, and the amount of water vapor in the air.

[0002] Conventionally, a device has been disclosed that uses a coherent differential absorption lidar (LiDAR; Light Detection and Ranging) to measure wind direction, wind speed, and the amount of water vapor in the air (see, for example, Non-Patent Document 1). This device measures line-of-sight wind by irradiating pulsed light, receiving scattered light from aerosols, and detecting the amount of Doppler shift using heterodyne detection. This device also calculates wind direction and speed by switching the line-of-sight direction during measurements. In addition, this device measures water vapor by switching the wavelength of the pulsed light irradiated between a water vapor absorption wavelength and a non-absorption wavelength and comparing the amount of scattered light received at each wavelength. This device then outputs wind direction, wind speed, and water vapor amount at predetermined measurement intervals.

[0003] Proc. of SPIE Vol. 12265 1226508-1, Remote Sensing of Clouds and the Atmosphere XXVII

[0004] The device described in Non-Patent Document 1 repeatedly switches its line of sight once every few seconds when measuring wind direction and speed, and since the measurement is stopped each time the line of sight is switched, it has the problem that it is difficult to shorten the measurement time.

[0005] The present disclosure was made in response to the recognition of the above-mentioned problems, and aims to provide a meteorological observation lidar device that can shorten the measurement time when measuring wind direction, wind speed, and the amount of water vapor in the air.

[0006] A meteorological observation lidar device according to the present disclosure includes a light source that generates laser light; a transceiver that selectively transmits the laser light from the light source toward a first direction, a second direction, and a third direction in the air and receives scattered light from the air; and a calculation unit that calculates wind direction, wind speed, and the amount of water vapor in the air based on interference light between the laser light from the light source and the scattered light, wherein the calculation unit calculates the wind direction and wind speed based on interference light between the laser light transmitted in the first direction for a first time period and the scattered light generated by the laser light, interference light between the laser light transmitted in the second direction for a second time period and the scattered light generated by the laser light, and interference light between the laser light transmitted in the third direction for a third time period and the scattered light generated by the laser light, and calculates the amount of water vapor in the air based on interference light between the laser light transmitted in any of the first, second, and third directions for a fourth time period that is longer than the first, second, and third times, and the scattered light generated by the laser light.

[0007] The meteorological observation lidar device according to the present disclosure can shorten the measurement time when measuring wind direction, wind speed, and the amount of water vapor in the air.

[0008] 1 is a block diagram showing a schematic configuration of a meteorological observation lidar device according to a first embodiment; FIG. 2 is a flowchart showing the operation of a laser transceiver module according to the first embodiment; FIG. 3 is a flowchart showing the operation performed by the meteorological observation lidar device according to the first embodiment in a wind direction and speed measurement mode; FIG. 4 is a flowchart showing the operation performed by the meteorological observation lidar device according to the first embodiment in a water vapor measurement mode; FIG. 5 is a block diagram showing a schematic configuration of a meteorological observation lidar device according to a second embodiment; FIG. 6 is a flowchart showing the operation performed by the meteorological observation lidar device according to the second embodiment in a wind direction and speed measurement mode; FIG. 7 is a flowchart showing the operation performed by the meteorological observation lidar device according to the second embodiment in a wind direction and speed measurement mode; FIG. 8 is a flowchart showing the operation performed by the meteorological observation lidar device according to the second embodiment in a water vapor measurement mode; FIG. 9 is a block diagram showing a schematic configuration of a meteorological observation lidar device according to a third embodiment; FIG. 10 is a flowchart showing the operation performed by the meteorological observation lidar device according to the third embodiment in a wind direction and speed measurement mode; FIG. 11 is a flowchart showing the operation performed by the meteorological observation lidar device according to the third embodiment in a wind direction and speed measurement mode;

[0009] Embodiments of the present disclosure will be described in detail below with reference to the drawings. Embodiment 1. <Configuration> First, the configuration of a meteorological observation lidar device 1 according to embodiment 1 will be described with reference to FIG. 1. FIG. 1 is a block diagram showing a schematic configuration of the meteorological observation lidar device 1 according to embodiment 1. As shown in FIG. 1, the meteorological observation lidar device 1 according to embodiment 1 includes, for example, a laser transceiver module 100, a spectrum integrator 23, a water vapor / wind direction and speed measurement switching device 27, a line-of-sight measurement control device 26, a water vapor calculation device 25, a wind direction and speed calculation device 24, and a data storage device 28. In embodiment 1, the water vapor calculation device 25 and the wind direction and speed calculation device 24 constitute a calculation unit that calculates wind direction, wind speed, and the amount of water vapor in the air.

[0010] The laser transceiver module 100 includes a trigger control device 19, a first laser light source 11, a second laser light source 12, a wavelength switching optical switch 13, an optical modulator 14, an optical amplifier 15, a circulator 16, a line-of-sight switching optical switch 17, a multi-line-of-sight telescope 18, a balanced receiver 20, an A / D converter 21, and an FFT device 22. In the first embodiment, the first laser light source 11 and the second laser light source 12 constitute light sources, and the multi-line-of-sight telescope 18 constitutes a transceiver unit.

[0011] The trigger control device 19 has a function of outputting a pulsed trigger signal that synchronizes the operation of each component included in the laser transmitting and receiving module 100 .

[0012] The first laser light source 11 has a function of emitting a first laser light (laser light ON) that is a laser light having a wavelength that absorbs water vapor.

[0013] The second laser light source 12 has a function of outputting a second laser light (laser light OFF) which is a laser light having a wavelength that is less absorbed by water vapor than the first laser light.

[0014] The wavelength switching optical switch 13 has a function of counting the number of pulsed trigger signals input from the trigger control device 19, and when a preset number of times is reached, after a preset time has elapsed, switching the laser light to be output from one of the first laser light input from the first laser light source 11 and the second laser light input from the second laser light source 12 to the other, and resetting the count. The wavelength switching optical switch 13 also has a function of outputting a wavelength switching signal indicating whether the first laser light source 11 or the second laser light source 12 is being output.

[0015] When a trigger signal is input from the trigger control device 19, the optical modulator 14 has the function of modulating the intensity of either the first laser light or the second laser light input via the wavelength switching optical switch 13 into a pulsed form after a predetermined time, and outputting modulated laser light generated by applying a predetermined frequency modulation to the frequency of the laser light.

[0016] The optical amplifier 15 starts operating when a measurement start signal is input from the line of sight measurement control device 26, amplifies and outputs the modulated laser light input from the optical modulator 14, and stops operating when a measurement stop signal is input from the line of sight measurement control device 26.

[0017] The circulator 16 has ports A, B, and C, and has the function of separating the output laser light from the input laser light, so that the laser light input to port A is output from port B, and the laser light input to port B is output from port C.

[0018] The line-of-sight switching optical switch 17 has one input port and multiple output ports, and has the function of outputting the laser light input from the circulator 16 to the input port from the output port corresponding to the line-of-sight setting signal input from the line-of-sight measurement control device 26, and outputting the laser light input to the output port from the input port.

[0019] The multi-line-of-sight telescope 18 has a plurality of input ports into which laser light from the line-of-sight switching optical switch 17 is input. When laser light is input from the line-of-sight switching optical switch 17 to one of the input ports, the telescope transmits the laser light into the air in a line-of-sight direction corresponding to the input port, receives scattered light from aerosol particles in the air, and outputs the scattered light from the original input port. For example, the multi-line-of-sight telescope 18 has four input ports and transmits laser light into the air in four line-of-sight directions D1, D2, D3, and D4 corresponding to the input ports. In the first embodiment, the line-of-sight direction D1 constitutes the first direction, the line-of-sight direction D2 constitutes the second direction, and the line-of-sight direction D3 constitutes the third direction.

[0020] The balanced receiver 20 has a function of multiplexing and detecting the laser light input from the wavelength switching optical switch 13 and the scattered light input from the circulator 16, converting the detected light into an electrical signal and outputting it. Specifically, the balanced receiver 20 has a function of multiplexing and detecting one of the first laser light and the second laser light input from the wavelength switching optical switch 13 and the scattered light input from the circulator 16 that is obtained from the air based on the laser light, converting the detected light into an electrical signal and outputting it.

[0021] The A / D converter 21 starts operation when a measurement start signal is input from the line-of-sight measurement control device 26, and has a function of outputting the electrical signal input from the balanced receiver 20 as digital data by A / D (Analog-to-Digital) conversion after a preset time when a trigger signal is input from the trigger control device 19. The A / D converter 21 also has a function of stopping operation when a measurement stop signal is input from the line-of-sight measurement control device 26.

[0022] The FFT device 22 has a function of converting the data input from the A / D converter 21 into spectrum data by FFT (Fast Fourier Transform) and outputting the spectrum data.

[0023] The spectral integration device 23 integrates data for each line of sight direction for the first laser light source 11 and the second laser light source 12 based on the wavelength switching signal input from the wavelength switching optical switch 13, the integration number setting signal input from the line of sight measurement control device 26, and the line of sight setting signal input from the line of sight measurement control device 26, and when a predetermined integration number is reached, outputs the data integrated for each line of sight direction for the first laser light source 11 and the second laser light source 12 together as integrated spectral data and outputs an integration end signal.

[0024] The water vapor / wind direction and speed measurement switching device 27 outputs a wind direction and speed measurement signal when operation starts, and has the function of switching the output signal between the wind direction and speed measurement signal and the water vapor measurement signal each time a measurement end signal is input from the line of sight measurement control device 26, and outputting either the wind direction and speed measurement signal or the water vapor measurement signal.

[0025] The line-of-sight measurement control device 26 switches between the wind direction and speed measurement mode and the water vapor measurement mode based on whether the signal input from the water vapor / wind direction and speed measurement switching device 27 is a wind direction and speed measurement signal or a water vapor measurement signal, and outputs a line-of-sight setting signal and an integration number setting signal based on the line-of-sight setting switching order and the integration number for each line-of-sight direction preset in each mode. The line-of-sight measurement control device 26 also has a function of outputting an amplifier operation signal and an amplifier stop signal for controlling the stop and operation of the optical amplifier 15 when switching the line-of-sight setting. When an integration end signal is input from the spectrum integration device 23, the line-of-sight measurement control device 26 determines that measurement in a specified line-of-sight direction has been completed and switches to the next line-of-sight direction. The line-of-sight measurement control device 26 also has a function of outputting a measurement end signal when measurements in all line-of-sight directions have been completed.

[0026] The water vapor calculation device 25 starts operating when a water vapor measurement signal is input from the water vapor / wind direction and speed measurement switching device 27, and has the function of comparing the measurement data of the first laser light source 11 and the second laser light source 12 from the integrated spectral data input from the spectral integration device 23, calculating the amount of water vapor in the air, and outputting water vapor measurement data indicating the calculated amount of water vapor in the air.

[0027] The wind direction and speed calculation device 24 starts operating when a wind direction and speed measurement signal is input from the water vapor / wind direction and speed measurement switching device 27, and has the function of temporarily storing the integrated spectrum data input from the spectrum integration device 23, comparing the measurement results from each line of sight direction, calculating the wind direction and wind speed, and outputting wind direction and speed measurement data indicating the calculated wind direction and wind speed.

[0028] The data storage device 28 is composed of, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc., and stores information used by each component of the weather observation lidar device 1.

[0029] <Operation Flowchart> Next, the operation of the meteorological observation lidar device 1 according to the first embodiment will be described with reference to Figures 2 to 4. First, the operation of the laser transmitting and receiving module 100 will be described with reference to Figure 2. Figure 2 is a flowchart of laser transmission and reception measurement showing the operation of the laser transmitting and receiving module 100 according to the first embodiment.

[0030] First, when the laser transmitting and receiving module 100 starts operating, the trigger control device 19 generates a trigger signal for synchronizing the operation of each component (various devices) included in the laser transmitting and receiving module 100 (step ST01).

[0031] When the trigger control device 19 performs the operation of step ST01, the first laser light source 11 outputs the first laser light (laser light ON) having a wavelength that is absorbed by water vapor in the air to the wavelength switching optical switch 13 (step ST02).

[0032] When the first laser light source 11 performs the operation of step ST02, the second laser light source 12 outputs to the wavelength switching optical switch 13 a second laser light (laser light OFF) having a wavelength that is less easily absorbed by water vapor in the air than the first laser light (step ST03).

[0033] When the second laser light source 12 performs the operation of step ST03, the wavelength switching optical switch 13 counts the number of input trigger signals, and when the number exceeds a preset number, it switches which laser light to output between the input first laser light (laser light ON) and second laser light (laser light OFF), and outputs it to the optical modulator 14 and the balanced receiver 20. At this time, the wavelength switching optical switch 13 also outputs a wavelength switching signal indicating which laser light is being output to the spectrum integration device (step ST04).

[0034] When the wavelength switching optical switch 13 performs the operation of step ST04, the optical modulator 14 synchronizes with the input trigger signal, changes the frequency of the input first laser light (laser light ON) or second laser light (laser light OFF) by a certain amount, modulates the intensity into a pulsed form, and outputs it to the optical amplifier 15 (step ST05).

[0035] When the optical modulator 14 performs the operation of step ST05, the optical amplifier 15 starts operation in response to a measurement start signal, amplifies the input modulated laser light, and outputs the amplified laser light to the circulator 16 (step ST06).

[0036] When the optical amplifier 15 performs the operation of step ST06, the circulator 16 outputs the input amplified laser light as it is to the line-of-sight switching optical switch 17 as a transmission laser light (step ST07).

[0037] When the circulator 16 performs the operation of step ST07, the line-of-sight switching optical switch 17 outputs the input transmission laser light to one of the multiple output ports according to the input line-of-sight setting signal (step ST08).

[0038] When the line-of-sight optical switch 17 performs the operation of step ST08, the multi-line-of-sight telescope 18 outputs the transmitted laser light in a direction preset for each of the input ports. At this time, the multi-line-of-sight telescope 18 also receives the light scattered by the transmitted laser light as the received light, and outputs the received light to the circulator 16 via the line-of-sight optical switch 17 (step ST09).

[0039] When the multi-line-of-sight telescope 18 performs the operation of step ST09, the circulator 16 outputs the input received light directly to the balanced receiver 20 (step ST10).

[0040] When the circulator 16 performs the operation of step ST10, the balanced receiver 20 combines the input first laser light (laser light ON) or second laser light (laser light OFF) with the received light, performs heterodyne detection, and outputs the result as a received signal to the A / D converter 21 (step ST11).

[0041] When the balanced receiver 20 performs the operation of step ST11, the A / D converter 21 starts operation in response to a measurement start signal, and when a trigger signal is input, it starts A / D conversion of the input received signal after a preset time has elapsed, and outputs the converted received signal as received data, which is digital data (step ST12).

[0042] When the A / D converter 21 performs the operation of step ST12, the FFT device 22 divides the input reception data into predetermined time intervals, defines each bin as bin 1, bin 2, ..., performs FFT on each bin, and outputs the results obtained as reception spectrum data for each bin to the spectrum integration device 23 (step ST13).

[0043] Next, the operation performed by the meteorological observation lidar device 1 in the wind direction and speed measurement mode will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the operation performed by the meteorological observation lidar device 1 according to the first embodiment in the wind direction and speed measurement mode.

[0044] First, when the meteorological observation lidar device 1 starts operating in the wind direction and speed measurement mode, the water vapor / wind direction and speed measurement switching device 27 outputs a wind direction and speed measurement signal to the line of sight measurement control device 26 and the wind direction and speed calculation device 24, instructing operation in the wind direction and speed measurement mode (step ST21).

[0045] When the water vapor and wind direction and speed measurement switching device 27 performs the operation of step ST21, the line-of-sight measurement control device 26 outputs a measurement stop signal to the optical amplifier 15 and the A / D converter 21 (step ST22).

[0046] When the line-of-sight measurement control device 26 performs the operation of step ST22, the optical amplifier 15 and the A / D converter 21 stop operating (step ST23).

[0047] In step ST23, when the optical amplifier 15 and the A / D converter 21 stop operating, the line-of-sight measurement control device 26 outputs a line-of-sight setting signal to the line-of-sight switching optical switch 17 to determine the output port of the line-of-sight switching optical switch 17 in accordance with the line-of-sight measurement order and the respective cumulative numbers preset for wind direction and speed measurement, outputs an cumulative number setting signal to the spectrum integrating device 23 to determine the cumulative number, and then outputs a measurement start signal to the optical amplifier 15 and the A / D converter 21 (step ST24). This pre-set line-of-sight measurement order is performed only once for each line-of-sight direction. The cumulative number for each line-of-sight direction lasts for approximately several seconds. In the first embodiment, among the cumulative numbers for each line-of-sight direction, the time corresponding to the cumulative number for line-of-sight direction D1 constitutes a first time period, the time corresponding to the cumulative number for line-of-sight direction D2 constitutes a second time period, and the time corresponding to the cumulative number for line-of-sight direction D3 constitutes a third time period.

[0048] When the line of sight measurement control device 26 performs the operation of step ST24, the laser transmitting / receiving module 100 operates each component (device) of the laser transmitting / receiving module 100, including the optical amplifier 15 and the A / D converter 21, in accordance with the flowchart of the laser transmitting / receiving measurement shown in Figure 2, and the received spectrum data is output from the FFT device 22 to the spectrum integration device 23 (step ST26).

[0049] When the laser transmitter / receiver module 100 performs the operation of step ST26, the spectrum integrator 23 distinguishes and integrates the first laser light (laser light ON), the second laser light (laser light OFF), the measurement line of sight direction, and the bin based on the input integration number setting signal, line of sight setting signal, and wavelength switching signal (step ST30).

[0050] When the spectrum integrating device 23 performs the operation of step ST30, it counts the number of times the received spectrum has been integrated and determines whether the result matches the number of times specified by the integration setting signal (step ST32).If the result does not match (NO in step ST32), the operation returns to step ST26, and the operations from step ST26 to step ST30 are executed again.

[0051] In the operation of step ST32, if the count result of the number of times the received spectrum has been integrated matches the number of times specified by the integration setting signal (YES in step ST32), the spectrum integration device 23 outputs the integrated received spectrum data as integrated spectrum data. At this time, the spectrum integration device 23 also resets the number of times the received spectrum has been integrated to 0. At this time, the spectrum integration device 23 also outputs an integration end signal to the line-of-sight measurement control device (step ST33).

[0052] When the spectrum integrating device 23 performs the operation of step ST33, the wind direction and speed calculation device 24 starts operation based on the input of the wind direction and speed calculation signal, and temporarily stores the input integrated spectrum data (step ST34).

[0053] When the wind direction and speed calculation device 24 performs the operation of step ST34, the line-of-sight measurement control device 26 determines whether measurements in the predetermined line-of-sight measurement order have been performed based on the input of the integration end signal (step ST38). Specifically, the line-of-sight measurement control device 26 determines whether all line-of-sight setting signals in the predetermined line-of-sight measurement order have been output.

[0054] In the operation of step ST38, if all measurements in the gaze measurement order have not been performed (NO in step ST38), the gaze measurement control device 26 outputs a measurement stop signal to the optical amplifier 15 and the A / D converter 21, outputs a gaze setting signal and an accumulation number setting signal corresponding to the next gaze measurement order, returns the operation to step ST22, and the operations from step ST22 to step ST34 are executed again.

[0055] In the operation of step ST38, if all measurements in the gaze measurement sequence have been performed (YES in step ST38), the gaze measurement control device 26 outputs a measurement end signal to the wind direction and wind speed calculation device 24 and the water vapor / wind direction and wind speed measurement switching device 27 (step ST39).

[0056] When the line-of-sight measurement control device 26 performs the operation of step ST39, the wind direction and speed calculation device 24 calculates the wind direction and speed for each bin using the temporarily stored integrated spectral data from each line-of-sight measurement, and outputs the calculation results to the data storage device as wind direction and speed calculation data (step ST41). At this time, the wind direction and speed calculation device 24 also erases the temporarily stored integrated spectral data. In the operation of step ST41, the wind direction and speed calculation device 24 calculates the wind direction and speed according to the procedure shown in, for example, Non-Patent Document 1.

[0057] When the wind direction and speed calculation device 24 performs the operation of step ST41, the data storage device 28 stores the input wind direction and speed calculation data together with the time (step ST42).

[0058] When the data storage device 28 performs the operation of step ST42, the water vapor / wind direction and speed measurement switching device 27 outputs a water vapor measurement signal that transitions the meteorological observation lidar device 1 to water vapor measurement mode based on the input of the measurement end signal.

[0059] When the water vapor and wind direction and speed measurement switching device 27 outputs the water vapor measurement signal, the meteorological observation lidar device 1 transitions to the water vapor measurement mode.

[0060] Next, the operation performed by the meteorological observation lidar device 1 in the water vapor measurement mode will be described with reference to Fig. 4. Fig. 4 is a flowchart showing the operation performed by the meteorological observation lidar device 1 according to the first embodiment in the water vapor measurement mode.

[0061] First, when the meteorological observation lidar device 1 starts operation in the water vapor measurement mode, the water vapor / wind direction and speed measurement switching device 27 outputs a water vapor measurement signal to the line-of-sight measurement control device 26 (step ST51).

[0062] When the water vapor / wind direction and speed measurement switching device 27 performs the operation of step ST51, the line-of-sight measurement control device 26 outputs a line-of-sight setting signal to the line-of-sight switching optical switch 17 and the spectrum integrating device 23, an integration number setting signal to the spectrum integrating device 23, and a measurement start signal to the optical amplifier 15 and the A / D converter 21 based on the water vapor measurement line of sight and integration number previously set for water vapor measurement (step ST52). This integration number is set to about 10 minutes, which is longer than the wind direction and speed measurement. In the first embodiment, the time corresponding to this integration number constitutes the fourth time period.

[0063] When the line of sight measurement control device 26 performs the operation of step ST52, the laser transmitting / receiving module 100 operates each component (device) of the laser transmitting / receiving module 100 in accordance with the flowchart of laser transmitting / receiving measurement shown in Figure 2, and the received spectrum data is output from the FFT device 22 to the spectrum integration device 23 (step ST55).

[0064] When the laser transmitter / receiver module 100 performs the operation of step ST55, the spectrum integrator 23 distinguishes and integrates the first laser light (laser light ON), the second laser light (laser light OFF), the measurement line of sight direction, and the bin based on the input integration number setting signal, line of sight setting signal, and wavelength switching signal (step ST56).

[0065] When the spectrum integrating device 23 performs the operation of step ST56, the spectrum integrating device 23 counts the number of times the received spectrum has been integrated, and determines whether the result matches the number of times specified by the integration setting signal (step ST57).If the result does not match (NO in step ST57), the operation returns to step ST55, and the operations from step ST55 to step ST56 are executed again.

[0066] In the operation of step ST57, if the count result of the number of integrations matches the number of times specified by the integration setting signal (YES in step ST57), the spectrum integration device 23 outputs the integrated received spectrum data as integrated spectrum data to the water vapor calculation device 25. At this time, the spectrum integration device 23 also resets the number of integrations of the received spectrum to 0. At this time, the spectrum integration device 23 also outputs an integration end signal to the line-of-sight measurement control device (step ST58).

[0067] When the spectrum integrating device 23 performs the operation of step ST58, the line-of-sight measurement control device 26 outputs a measurement end signal to the water vapor calculation device 25 and the water vapor / wind direction and speed measurement switching device 27 (step ST60).

[0068] When the line-of-sight measurement control device 26 performs the operation of step ST60, the water vapor calculation device 25 calculates the amount of water vapor in the air for each bin using the integrated spectrum data obtained by distinguishing and integrating the input first laser light (laser light ON) and the second laser light (laser light OFF), and outputs the calculated data to the data storage device 28 (step ST61). In the operation of step ST61, the water vapor calculation device 25 calculates the amount of water vapor in the air according to the procedure shown in Non-Patent Document 1, for example.

[0069] When the water vapor calculation device 25 performs the operation of step ST61, the data storage device 28 stores the input water vapor calculation data together with the time (step ST63).

[0070] When the data storage device 28 performs the operation of step ST63, the water vapor / wind direction and speed measurement switching device 27 outputs a wind direction and speed measurement signal that transitions the weather observation lidar device 1 to wind direction and speed measurement mode based on the input of the measurement end signal.

[0071] When the water vapor / wind direction and speed measurement switching device 27 outputs the wind direction and speed measurement signal, the meteorological observation lidar device 1 transitions to the wind direction and speed measurement mode and again performs the operation of the flowchart for the wind direction and speed measurement mode shown in Figure 3.

[0072] As described above, the meteorological observation lidar device 1 according to the first embodiment includes a first laser light source 11 and a second laser light source 12 that generate laser light, a multi-line-of-sight telescope 18 that selectively transmits laser light from the first laser light source 11 and the second laser light source 12 in the line-of-sight direction D1, the line-of-sight direction D2, and the line-of-sight direction D3 in the air and receives scattered light from the air, and a wind direction and speed calculation device 24 and a water vapor calculation device 25 that calculate the wind direction, wind speed, and amount of water vapor in the air based on interference light between the laser light from the first laser light source 11 and the second laser light source 12 and the scattered light. The wind direction and speed calculation device 24 transmits laser light in the line-of-sight direction D1 for a first time, and receives scattered light from the air. The water vapor calculation device 25 is configured to calculate the wind direction and wind speed based on the interference light between the laser light transmitted in the line of sight D1, line of sight D2, or line of sight D3 for a second time period and the scattered light generated by the laser light, the interference light between the laser light transmitted in the line of sight D2 for a second time period and the scattered light generated by the laser light, and the interference light between the laser light transmitted in the line of sight D3 for a third time period and the scattered light generated by the laser light, and the water vapor calculation device 25 is configured to calculate the amount of water vapor in the air based on the interference light between the laser light transmitted in any one of the line of sight D1, line of sight D2, or line of sight D3 for a fourth time period that is longer than the first, second, and third times, and the scattered light generated by the laser light.

[0073] Configured in this way, the meteorological observation lidar device 1 can reduce the frequency of switching the line of sight when transmitting laser light in multiple line of sight directions to measure wind direction, wind speed, and the amount of water vapor in the air, thereby shortening the measurement time compared to conventional methods.

[0074] Furthermore, the meteorological observation lidar device 1 according to embodiment 1 is configured to have a wind direction and speed measurement mode and a water vapor measurement mode, and in the wind direction and speed mode it measures multiple line of sight directions only once for a short period of time, such as a few seconds, while in the water vapor measurement mode it continues to measure only one specific line of sight for a long period of time, such as about 10 minutes. This minimizes the measurement time loss due to switching line of sight directions, thereby maximizing the accumulated time and, as a result, improving the water vapor measurement accuracy and extending the measurable distance.

[0075] The meteorological observation lidar device may be configured to temporarily store the integrated spectral data measured in the wind direction and speed measurement mode in the water vapor calculation device, and to integrate the data together with the integrated spectral data measured in the water vapor calculation mode to calculate water vapor. With this configuration, the meteorological observation lidar device can increase the amount of data to be integrated, thereby improving the accuracy of water vapor measurement and extending the distance over which water vapor can be measured.

[0076] Furthermore, in a meteorological observation lidar device, the optical modulator may be configured with a device for applying frequency modulation and a device for pulsing intensity separated from each other. For example, when the optical modulator is configured with an AOM (Acousto-Optic Modulator), it performs frequency modulation and pulsing simultaneously, but it may also be configured with an LN modulator and an SOA (Semiconductor Optical Amplifier) ​​that are provided separately from each other, or a combination of the LN modulator and the SOA may be configured to perform frequency modulation and pulsing, respectively.

[0077] The meteorological observation lidar device 1 according to the first embodiment is configured to transmit and receive laser light in four line-of-sight directions D1 to D4, but is not limited to this. The number of line-of-sight directions for transmitting and receiving laser light may be three or more in order to measure wind direction, and may be three, four or more.

[0078] In the first embodiment, the measurement start signal and measurement stop signal may be configured as signals based on the magnitude of a voltage, or may be configured as a serial signal, etc. The measurement start signal and measurement stop signal are configured depending on the control interfaces of the optical amplifier and the A / D converter.

[0079] Second Embodiment <Configuration> Next, a meteorological observation lidar device 2 according to a second embodiment will be described with reference to Figures 5 to 8. The meteorological observation lidar device 2 according to the second embodiment differs from the meteorological observation lidar device 1 according to the first embodiment in that it newly includes an integrated spectrum S / N measurement device and a water vapor measurement line-of-sight selection device, but the other configurations are the same, and the same configurations as those in the first embodiment are assigned the same names and symbols as those in the first embodiment, and description thereof will be omitted.

[0080] Fig. 5 is a block diagram showing a schematic configuration of a meteorological observation lidar device 2 according to embodiment 2. As shown in Fig. 5, the meteorological observation lidar device 2 according to embodiment 2 includes, for example, a laser transceiver module 100, a spectrum integrating device 23, a water vapor / wind direction and speed measurement switching device 27, a line-of-sight measurement control device 26, a water vapor calculation device 25, a wind direction and speed calculation device 24, a data storage device 28, an integrated spectrum S / N measurement device 29, and a water vapor measurement line-of-sight selection device 30.

[0081] The integrating spectrum S / N measuring device 29 has a function of calculating a received S / N (signal-to-noise ratio) based on the integrated spectrum data input from the spectrum integrating device 23. In other words, the integrating spectrum S / N measuring device 29 has a function of measuring the signal-to-noise ratio of scattered light received when the wind direction and wind speed calculating device 24 calculates the wind direction and wind speed. In the second embodiment, the integrating spectrum S / N measuring device 29 constitutes a signal-to-noise ratio measuring unit. The integrating spectrum S / N measuring device 29 outputs the calculation result as integrated spectrum S / N measurement data.

[0082] The water vapor measurement line-of-sight selection device 30 has the function of temporarily storing the input integrated spectrum S / N measurement data and the line-of-sight setting specified by the line-of-sight setting signal, determining the water vapor measurement line-of-sight direction from this information, and outputting a water vapor measurement line-of-sight signal indicating the determined water vapor measurement line-of-sight direction.

[0083] <Operation Flowchart> Next, the operation of the meteorological observation lidar device 2 according to the second embodiment will be described with reference to Figures 6 to 8. First, the operation performed by the meteorological observation lidar device 2 in the wind direction and speed measurement mode will be described with reference to Figures 6 and 7. Figures 6 and 7 are flowcharts showing the operation performed by the meteorological observation lidar device 2 according to the second embodiment in the wind direction and speed measurement mode. Note that some of the operations performed by the meteorological observation lidar device 2 according to the second embodiment in the wind direction and speed measurement mode are similar to the operations performed by the meteorological observation lidar device 1 according to the first embodiment in the wind direction and speed measurement mode, and operations similar to those in the first embodiment will be assigned the same reference numerals as in the first embodiment, and descriptions thereof will be omitted.

[0084] When the wind direction and speed calculation device 24 performs the operation of step ST34, the integrated spectrum S / N measurement device 29 calculates the S / N from the integrated spectrum data and outputs the integrated spectrum S / N measurement data to the water vapor measurement line of sight selection device 30 (step ST35).

[0085] When the integrated spectrum S / N measuring device 29 performs the operation of step ST35, the water vapor measurement line of sight selection device 30 starts operation based on the input of the wind direction and wind speed measurement signal, and temporarily stores the input integrated spectrum S / N measurement data together with the line of sight setting indicated by the line of sight setting signal (step ST36).

[0086] When the water vapor measurement gaze selection device 30 performs the operation of step ST36, the gaze measurement control device 26 determines whether measurements have been performed in the predetermined gaze measurement order based on the input of an accumulation end signal (step ST38).

[0087] When the data storage device 28 performs the operation of step ST42, the water vapor measurement gaze selection device 30, based on the input of the measurement end signal, selects the gaze direction with the largest S / N ratio using the temporarily stored integrated spectral S / N measurement data and gaze setting, and outputs a water vapor measurement gaze signal indicating the selection result to the gaze measurement control device 26 (step ST43).

[0088] Next, the operation performed by the meteorological observation lidar device 2 in the water vapor measurement mode will be described with reference to Fig. 8. Fig. 8 is a flowchart showing the operation performed by the meteorological observation lidar device 2 in the water vapor measurement mode according to embodiment 2. Note that some of the operations performed by the meteorological observation lidar device 2 in the water vapor measurement mode according to embodiment 2 are similar to the operations performed by the meteorological observation lidar device 1 in embodiment 1 in the water vapor measurement mode, and operations similar to those in embodiment 1 will be assigned the same reference numerals as in embodiment 1 and will not be described again.

[0089] When the water vapor / wind direction and speed measurement switching device 27 performs the operation of step ST51, the line of sight measurement control device 26 outputs a line of sight setting signal, an accumulation number setting signal, and a measurement start signal based on the input water vapor measurement line of sight signal and the predetermined accumulation number (step ST53).

[0090] When the line of sight measurement control device 26 performs the operation of step ST53, the laser transmitting / receiving module 100 operates each component (device) of the laser transmitting / receiving module 100 in accordance with the flowchart of laser transmitting / receiving measurement shown in Figure 2, and the received spectrum data is output from the FFT device 22 to the spectrum integration device 23 (step ST55).

[0091] As described above, the meteorological observation lidar device 2 according to the second embodiment includes an integrated spectrum S / N measuring device 29 that measures the S / N of the scattered light received when the wind direction and wind speed are calculated by the wind direction and speed calculating device 24, and the water vapor calculating device 25 is configured to calculate the amount of water vapor in the air based on the interference light between the laser light transmitted for the fourth time in the direction of the line of sight D1 or the line of sight D2, whichever has the larger S / N measured by the integrated spectrum S / N measuring device 29, and the scattered light generated by the laser light.

[0092] With this configuration, the meteorological observation lidar device 2 can obtain sufficient measurement accuracy when measuring the amount of water vapor in the air in a shorter time than before, thereby shortening the measurement time compared to before.

[0093] Furthermore, the meteorological observation lidar device 2 according to the second embodiment uses the reception S / N ratio measured for each line of sight direction when measuring wind direction and wind speed to determine the line of sight direction with the highest reception S / N ratio, and sets this as the line of sight when measuring water vapor, thereby maximizing the reception S / N ratio, improving the accuracy of water vapor measurement, and extending the distance over which water vapor can be measured.

[0094] Generally, in a device such as the meteorological observation lidar device 2 of embodiment 2, the line-of-sight switching optical switch and the multi-line-of-sight telescope have different laser light transmission characteristics for each output port due to manufacturing tolerances, and as a result, the reception S / N ratio when laser transmission and reception is performed differs for each output port.

[0095] Furthermore, in such a device, the multi-line-of-sight telescope experiences degradation of the laser transmission and reception pass characteristics due to partial contamination on the surface of the output end caused by external environments such as rain and wind, and this degradation differs depending on the line of sight. The meteorological observation lidar device 2 according to the second embodiment can minimize the degradation of the pass characteristics by selecting the line of sight direction with the highest reception S / N ratio, thereby achieving the above-mentioned effects.

[0096] 9 to 12, a meteorological observation lidar device 3 according to the third embodiment will be described. The meteorological observation lidar device 3 according to the third embodiment differs from the meteorological observation lidar device 2 according to the second embodiment in that it newly includes a single-measurement S / N measuring device, a wind speed integrated number calculating device, and a water vapor integrated number calculating device, but the other configurations are the same. The same configurations as those in the second embodiment are denoted by the same names and symbols as those in the second embodiment, and description thereof will be omitted.

[0097] 9 is a block diagram showing a schematic configuration of a meteorological observation lidar device 3 according to embodiment 3. As shown in Fig. 9, the meteorological observation lidar device 3 according to embodiment 3 includes, for example, a laser transceiver module 100, a spectrum integrating device 23, a water vapor / wind direction and speed measurement switching device 27, a line-of-sight measurement control device 26, a water vapor calculation device 25, a wind direction and speed calculation device 24, a data storage device 28, an integrated spectrum S / N measurement device 29, a water vapor measurement line-of-sight selection device 30, a single-measurement S / N measurement device 31, a wind speed integrated number calculation device 32, and a water vapor integrated number calculation device 33.

[0098] The single-measurement S / N measuring device 31 has a function of measuring the reception S / N from the reception spectrum data and outputting the measurement result as single-measurement S / N measurement data. In the third embodiment, the single-measurement S / N measuring device 31 constitutes a single-measurement signal-to-noise ratio measuring unit.

[0099] The wind speed integrated number calculation device 32 has a function of outputting a wind speed integrated number signal from the single measurement S / N measurement data input from the single measurement S / N measurement device 31 and a preset S / N required for wind speed measurement. In the third embodiment, the wind speed integrated number calculation device 32 constitutes a wind speed integrated number calculation unit.

[0100] The water vapor integrated number calculation device 33 has the function of measuring the time spent in the wind direction and speed measurement mode from the integrated number in each line of sight, based on the line of sight setting signal input from the line of sight measurement control device 26 and the wind speed integrated number signal input from the wind speed integrated number calculation device 32, subtracting the time spent in the wind direction and speed measurement mode from the preset time interval for outputting measurement results of the amount of water vapor in the air and wind direction and wind speed, setting the integrated number so that the time equivalent to the remaining time is used to measure the amount of water vapor, and outputting a water vapor integrated number signal indicating the set integrated number.In addition, in embodiment 3, the water vapor integrated number calculation device 33 constitutes a water vapor integrated number calculation unit.

[0101] <Operation Flowchart> Next, the operation of the meteorological observation lidar device 3 according to the third embodiment will be described with reference to Figures 10 to 12. First, the operation performed by the meteorological observation lidar device 3 in the wind direction and speed measurement mode will be described with reference to Figures 10 and 11. Figures 10 and 11 are flowcharts showing the operation performed by the meteorological observation lidar device 3 according to the third embodiment in the wind direction and speed measurement mode. Note that some of the operations performed by the meteorological observation lidar device 3 according to the third embodiment in the wind direction and speed measurement mode are similar to the operations performed by the meteorological observation lidar device 2 according to the second embodiment in the wind direction and speed measurement mode, and operations similar to those in the second embodiment will be assigned the same reference numerals as in the second embodiment, and descriptions thereof will be omitted.

[0102] In step ST23, when the optical amplifier 15 and A / D converter 21 stop operating, the line of sight measurement control device 26 outputs a line of sight setting signal to the line of sight switching optical switch 17 to determine the output port of the line of sight switching optical switch 17 in accordance with the line of sight measurement order previously set for wind direction and speed measurement, and then outputs a measurement start signal to the optical amplifier 15 and A / D converter 21 (step ST25).

[0103] When the line of sight measurement control device 26 performs the operation of step ST25, the laser transmitting / receiving module 100 operates each component (device) of the laser transmitting / receiving module 100, including the optical amplifier 15 and the A / D converter 21, in accordance with the flowchart of the laser transmitting / receiving measurement shown in Figure 2, and the received spectrum data is output from the FFT device 22 to the spectrum integration device 23 (step ST26).

[0104] When the laser transmitter / receiver module 100 performs the operation of step ST26, the one-measurement S / N measuring device 31 calculates the received signal S / N from the received spectrum data and outputs the calculation result to the wind speed cumulative number calculating device 32 as one-measurement S / N measurement data (step ST27).

[0105] When the one-measurement S / N measuring device 31 performs the operation of step ST27, the wind speed integrated number calculation device 32 calculates the integrated number based on the input one-measurement S / N measurement data and the preset S / N required for wind speed measurement, and outputs the calculation result as a wind speed integrated number signal to the line-of-sight measurement control device 26 and the water vapor integrated number calculation device 33 (step ST28). For example, if the one-measurement S / N is A and the required S / N is B, the integrated number N is calculated by the following formula (1): N=(B / A) ２ ...(1)

[0106] When the wind speed integrated number calculation device 32 performs the operation of step ST28, the line-of-sight measurement control device 26 outputs an integrated number setting signal to the spectrum integration device 23 based on the input wind speed integrated number signal (step ST29).

[0107] When the line-of-sight measurement control device 26 performs the operation of step ST29, the spectrum integration device 23 distinguishes between the first laser light (laser light ON), the second laser light (laser light OFF), and the measurement line-of-sight direction based on the input line-of-sight setting signal and wavelength switching signal, and integrates them (step ST31).

[0108] After performing the operation of step ST31, the spectrum integrating device 23 counts the number of times the received spectrum has been integrated, and determines whether the result matches the number of times specified by the integration setting signal (step ST32).

[0109] When the water vapor measurement line of sight selection device 30 performs the operation of step ST36, the water vapor accumulated number calculation device 33 temporarily stores the accumulated numbers for each line of sight direction based on the input wind speed accumulated number signal and line of sight setting signal (step ST37).

[0110] When the water vapor accumulated number calculation device 33 performs the operation of step ST37, the gaze measurement control device 26 determines whether measurements have been performed in the predetermined gaze measurement order based on the input of an accumulation end signal (step ST38).

[0111] When the line-of-sight measurement control device 26 performs the operation of step ST39, the water vapor integrated number calculation device 33, based on the measurement end signal input, measures the time taken for the wind direction and speed measurement mode from the integrated numbers in each line-of-sight direction that have been saved (step ST40). The time interval between trigger signals in a certain line-of-sight direction is Δt1, and the integrated number is N ｗｉｎｄ１ , If the time required to start, stop, and restart the gaze switching is Δt2, the time required for that gaze T ｗｉｎｄ１ is calculated by the following formula (2): ｗｉｎｄ１ = Δt1 × N ｗｉｎｄ１ +Δt2...(2)

[0112] The time taken in the wind direction and speed measurement mode is the sum of the times calculated in each line of sight direction as described above. For example, the time taken to measure the line of sight direction D1 is T ｗｉｎｄ１ , the time taken to measure the line of sight direction D2 is T ｗｉｎｄ２ , ..., the time T taken in the wind direction and speed measurement mode is ｗｉｎｄis calculated by the following formula (3): ｗｉｎｄ =T ｗｉｎｄ１ +T ｗｉｎｄ２ + ... (3)

[0113] In addition, in the operation of step ST40, the water vapor integrated number calculation device 33 subtracts the time taken for the wind direction and wind speed measurement mode from the time interval for outputting the measurement results of the amount of water vapor in the air, wind direction, and wind speed set in advance, sets the integrated number so that the time corresponding to the remaining time is used for water vapor measurement, and outputs a water vapor integrated number signal indicating the set integrated number. ｍｅａｓｕｒｅ If the measurement results of the amount of water vapor in the air, wind direction and wind speed are output once every 10 seconds, the water vapor measurement time T ｗａｔｅｒ is calculated by the following formula (4): ｗａｔｅｒ =T ｍｅａｓｕｒｅ -T ｗｉｎｄ ...(4)

[0114] Next, the water vapor cumulative number calculation device 33 calculates the cumulative number from the time of the water vapor measurement. ｗａｔｅｒ is calculated by the following formula (5): ｗａｔｅｒ = (T ｗａｔｅｒ −Δt2) / Δt1 (5) The water vapor integrated number calculation device 33 outputs a water vapor integrated number signal corresponding to this integrated number to the line-of-sight measurement control device 26.

[0115] Next, the operation performed by the meteorological observation lidar device 3 in the water vapor measurement mode will be described with reference to Fig. 12. Fig. 12 is a flowchart showing the operation performed by the meteorological observation lidar device 3 according to embodiment 3 in the water vapor measurement mode. Note that some of the operations performed by the meteorological observation lidar device 3 according to embodiment 3 in the water vapor measurement mode are similar to the operations performed by the meteorological observation lidar device 2 according to embodiment 2 in the water vapor measurement mode, and operations similar to those in embodiment 2 are denoted by the same reference numerals as in embodiment 2, and descriptions thereof will be omitted.

[0116] When the water vapor / wind direction and speed measurement switching device 27 performs the operation of step ST51, the line of sight measurement control device 26 outputs a line of sight setting signal, an accumulation number setting signal, and a measurement start signal based on the input water vapor measurement line of sight signal and water vapor accumulation number signal (step ST54).

[0117] When the line of sight measurement control device 26 performs the operation of step ST54, the laser transmitting and receiving module 100 operates each component (device) of the laser transmitting and receiving module 100 in accordance with the flowchart of the laser transmitting and receiving measurement shown in Figure 2, and the received spectrum data is output from the FFT device 22 to the spectrum integration device 23 (step ST55).

[0118] When the spectrum integrating device 23 performs the operation of step ST58, the water vapor calculating device 25 temporarily stores the input integrated spectrum data (step ST59).

[0119] When the water vapor calculation device 25 performs the operation of step ST59, the line-of-sight measurement control device 26 outputs a measurement end signal to the water vapor calculation device 25 and the water vapor / wind direction and speed measurement switching device 27 (step ST60).

[0120] When the line-of-sight measurement control device 26 performs the operation of step ST60, the water vapor calculation device 25 calculates the amount of water vapor using the temporarily stored integrated spectrum data and outputs the calculated amount of water vapor as water vapor calculation data (step ST62).

[0121] When the water vapor calculation device 25 performs the operation of step ST62, the data storage device 28 stores the input water vapor calculation data together with the time (step ST63).

[0122] As described above, the meteorological observation lidar device 3 according to the third embodiment calculates the wind direction, wind speed, and amount of water vapor in the air by integrating the spectral data of one measurement of the interference light between the laser light from the first laser light source 11 and the second laser light source 12 and the scattered light, and includes a single-measurement S / N measuring device 31 that measures the signal-to-noise ratio of one measurement of the wind direction and wind speed from the spectral data of the interference light between the laser light from the first laser light source 11 and the second laser light source 12 and the scattered light, and a single-measurement S / N measuring device 32 that measures the signal-to-noise ratio of one measurement of the wind direction and wind speed based on the S / N of one measurement of the wind direction and wind speed measured by the single-measurement S / N measuring device 31. and a water vapor accumulation number calculation device 33 that calculates a fourth time based on the first time, the second time, and the third time, and calculates an accumulated number by which spectral data of one measurement of the interference light of the laser light from the first laser light source 11 and the second laser light source 12 and the scattered light is accumulated when calculating the amount of water vapor in the air based on the calculated fourth time.

[0123] For example, the meteorological observation lidar device 3 according to the third embodiment can minimize the time required for wind direction and speed measurement by measuring the S / N of one measurement data item in each line of sight measurement in the wind direction and speed measurement mode and setting the number of integrations to satisfy the required S / N. Furthermore, the meteorological observation lidar device 3 according to the third embodiment can maximize the time required for water vapor measurement and increase the number of integrations by minimizing the time required for wind direction and speed measurement within the time interval set for the device between water vapor measurement and outputting wind direction and speed measurement data, thereby improving the accuracy of water vapor measurement and extending the distance over which water vapor can be measured.

[0124] Furthermore, the meteorological observation lidar device 3 according to the third embodiment can prevent deterioration in the accuracy of wind direction and speed measurements by controlling the number of times wind direction and speed measurements are accumulated in accordance with changes in the reception S / N ratio due to environmental changes.

[0125] Generally, the amount of aerosol particles in the atmosphere varies depending on the environment, and the intensity of the scattered light also fluctuates, resulting in fluctuations in the received S / N ratio. One possible solution to fluctuations in the received S / N ratio is to set a higher number of wind direction and speed integrations to allow for a margin in anticipation of environmental fluctuations. However, this requires extra time for wind direction and speed measurement, which ultimately reduces the water vapor measurement time. Generally, the required S / N ratio for water vapor measurement is significantly different from that for wind direction and speed measurement, and a long integration time is required for water vapor measurement. Furthermore, since the accuracy of water vapor measurement and the distance over which water vapor can be measured depend on the received S / N ratio, it is necessary to allocate as much measurement time as possible for water vapor measurement and increase the number of integrations.

[0126] The meteorological observation lidar device 3 of embodiment 3, with the above-described configuration, can respond to changes in the reception S / N ratio due to environmental fluctuations, and by minimizing the time required to measure wind direction and speed, maximizes the time required to measure water vapor, thereby improving the accuracy of water vapor measurement and extending the distance over which water vapor can be measured.

[0127] If there are no constraints on the time interval between outputting water vapor measurement data and wind direction and speed measurement data, the weather observation lidar device may be configured to measure the S / N ratio for one measurement in the water vapor measurement, as in the wind direction and speed measurement, and set an integrated number calculated from a predetermined required S / N ratio. This makes it possible to maintain the water vapor measurement accuracy and water vapor measurable distance regardless of environmental fluctuations.

[0128] In any of the above-described embodiments, the laser transmitting and receiving module may include some or all of the other components of the meteorological observation lidar device, or some of the components of the laser transmitting and receiving module may be provided in another device that is connected to the laser transmitting and receiving module so that information can be transmitted.

[0129] In addition, the present disclosure allows for free combination of the respective embodiments, modification of any of the components of the respective embodiments, or omission of any of the components of the respective embodiments.

[0130] The meteorological observation lidar device according to the present disclosure can be used to observe wind direction, wind speed, and the amount of water vapor in the air.

[0131] 1 Meteorological observation lidar device, 2 Meteorological observation lidar device, 3 Meteorological observation lidar device, 11 First laser light source (light source), 12 Second laser light source (light source), 13 Wavelength switching optical switch, 14 Optical modulator, 15 Optical amplifier, 16 Circulator, 17 Line of sight switching optical switch, 18 Multi-line of sight telescope (transmitter / receiver), 19 Trigger control device, 20 Balanced receiver, 21 A / D converter, 22 FFT device, 23 Spectral integration device, 24 Wind direction and speed calculation device (calculation unit), 25 Water vapor calculation device (calculation unit), 26 Line of sight measurement control device, 27 Water vapor / wind direction and speed measurement switching device, 28 Data storage device, 29 Integrated spectrum S / N measurement device (signal-to-noise ratio measurement unit), 30 Water vapor measurement line of sight selection device, 31 1 measurement S / N measurement device (1 measurement signal-to-noise ratio measurement unit), 32 Wind speed integrated number calculation device (wind speed integrated number calculation unit), 33 Water vapor cumulative number calculation device (water vapor cumulative number calculation unit), 100 laser transmitting and receiving module, A port, B port, C port, D1 line of sight direction (first direction), D2 line of sight direction (second direction), D3 line of sight direction (third direction), D4 line of sight direction.

Claims

1. A meteorological observation lidar device comprising: a light source that generates laser light; a transceiver unit that selectively transmits laser light from said light source toward a first direction, a second direction, and a third direction in the air, and receives scattered light from the air; and a calculation unit that calculates wind direction, wind speed, and the amount of water vapor in the air based on interference light between the laser light from said light source and the scattered light, wherein said calculation unit calculates wind direction and wind speed based on interference light between the laser light transmitted in said first direction for a first time period and the scattered light generated by said laser light, interference light between the laser light transmitted in said second direction for a second time period and the scattered light generated by said laser light, and interference light between the laser light transmitted in said third direction for a third time period and the scattered light generated by said laser light, and calculates the amount of water vapor in the air based on interference light between the laser light transmitted in any of said first, second, and third directions for a fourth time period that is longer than said first, second, and third times, and the scattered light generated by said laser light.

2. A meteorological observation lidar device as described in claim 1, characterized in that it is provided with a signal-to-noise ratio measuring unit that measures the signal-to-noise ratio of scattered light received when the calculation unit calculates wind direction and wind speed, and the calculation unit calculates the amount of water vapor in the air based on the interference light between the laser light transmitted for the fourth period in the direction of the first direction or the second direction that has the larger signal-to-noise ratio measured by the signal-to-noise ratio measuring unit and the scattered light generated by the laser light.

3. The meteorological observation lidar device according to claim 1 or 2, characterized in that the calculation unit calculates wind direction, wind speed, and the amount of water vapor in the air by integrating spectral data of one measurement of interference light between laser light and scattered light from the light source; a single measurement signal-to-noise ratio measurement unit that measures the signal-to-noise ratio of one measurement of wind direction and wind speed from the spectral data of interference light between laser light and scattered light from the light source; a wind speed integration number calculation unit that calculates an integration number by which spectral data of one measurement of interference light between laser light and scattered light from the light source in the line of sight direction corresponding to one measurement of wind direction and wind speed, based on the signal-to-noise ratio of one measurement of wind direction and wind speed measured by the single measurement signal-to-noise ratio measurement unit; and a water vapor integration number calculation unit that calculates the fourth time based on the first time, the second time, and the third time, and calculates an integration number by which spectral data of one measurement of interference light between laser light and scattered light from the light source is integrated when calculating the amount of water vapor in the air based on the calculated fourth time.