JP4266810B2 - Wind speed vector calculation device - Google Patents

Description

  The present invention relates to a wind speed vector calculating device used in a wind speed measuring apparatus that measures an air speed by radiating electromagnetic waves into a space and receiving electromagnetic waves reflected in the atmosphere.

  Observation of the spatial distribution of wind speed is an important observation item in weather monitoring and weather forecasting. For example, in airport weather Doppler radar, the position where the wind is changing suddenly is detected by observing the wind speed distribution around the runway. This detection result is reflected in the flight plan and contributes to improving the safety of air traffic. In a radar that performs wind observation using such a Doppler effect, only the wind speed component in the line-of-sight direction when the observation target is viewed from the radar is measured, and the wind speed component in the direction orthogonal to the radar line-of-sight direction is directly measured. I can't. However, there are many needs to observe the wind speed vector by measuring the wind speed component in the direction orthogonal to the direction of the line of sight of the radar.

  In order to meet the above-described needs, there is an observation method in which Doppler radars are arranged at a plurality of points, the same observation area is observed simultaneously, and Doppler velocities measured from different directions are combined to calculate a wind speed vector. However, since the use of a plurality of Doppler radars is expensive, an observation method for calculating a wind speed vector with a single Doppler radar is often used. In this case, the wind speed vector is obtained by synthesizing Doppler velocities obtained in different observation directions using the assumption that the wind speed distribution of the atmospheric air to be observed is spatially uniform. One of these methods is called a VAD (Velocity Azimuth Display) method (for example, see Non-Patent Document 1). As a method for calculating a wind speed vector using Doppler velocities observed in a small number of beam directions, there is a technique called a wind profiler (for example, see Non-Patent Document 2 and Patent Document 1).

JP 2001-159636 A H. Sauvageot, “Rader Meteorology”, U.S.A., Artech House, INC. 1992, p.210-213 D. A. Carter et al., Development in UHF lower tropospheric wind profiling at NOAA ’s Aeronomy Laboratory ”, Radio Science, vol.30, Number.4, 1995, pp.977-1001

  All of the conventional methods for calculating the wind speed vector are calculated by combining Doppler velocities observed in a plurality of different beam directions, assuming the spatial uniformity of the wind. This is not a problem when the time resolution of the wind speed measurement is low because the time average length is long, but when the time resolution is high, the time series changes only for the time when the spatial distribution of the wind is spatially propagated. There is a problem that a time difference occurs and an error occurs in wind speed vector calculation. This situation will be described with reference to FIG. In the figure, it is assumed that the Doppler speed is observed in two directions, direction 1 and direction 2, and the wind speed vector is calculated using the Doppler speed. Here, it is assumed that an air mass having a temporarily high wind speed passes in a state where the wind exists in the direction from the lower right to the upper left in the figure. In this case, the Doppler velocity observed in directions 1 and 2 is as shown in FIG. That is, a large Doppler velocity is first observed in direction 2, and then a large Doppler velocity is observed in direction 1. In this way, a time difference occurs in the time-series change of the Doppler velocity depending on the beam direction by the time difference corresponding to the spatial propagation time of the wind speed spatial distribution. However, since the conventional method does not consider such a time difference, the accuracy of the wind speed vector calculation has deteriorated.

  The present invention has been made to solve the above problems, and in a wind speed measuring apparatus using a radar, a highly accurate wind speed vector is calculated by taking into account the spatial propagation time or spatial propagation direction of the wind speed spatial distribution. It is an object of the present invention to obtain a wind speed vector calculation device capable of performing the above.

  The wind speed vector calculation apparatus according to the present invention radiates electromagnetic waves into space, receives electromagnetic waves reflected in the atmosphere, calculates a Doppler speed by frequency analysis, and calculates a wind speed vector of a wind speed measuring apparatus that obtains the wind speed from the Doppler speed. A device that calculates the Doppler velocity of the atmosphere obtained by directing the beam in a plurality of different directions, and the spatial propagation in which the wind velocity spatial distribution propagates through the space based on the calculated Doppler velocity Doppler velocity that compensates by moving the time series of Doppler velocities obtained by each beam calculated by the spatial distribution propagation time estimator that estimates time and the Doppler velocity calculator by the time corresponding to the estimated spatial propagation time A wind speed vector that calculates a wind speed vector based on a time series of time compensation units and a time series of Doppler velocities after propagation time compensation for a plurality of beam directions It is obtained by a detecting section.

  According to the present invention, since the spatial propagation time of the wind speed spatial distribution is estimated and compensated from the time series of Doppler velocities observed in different beam directions, it is possible to perform highly accurate wind speed vector calculation. There is.

Embodiment 1 FIG.
FIG. 2 is a block diagram showing the overall configuration of a typical wind speed vector measuring apparatus to which the wind speed vector calculating apparatus of the present invention is applied. In the figure, the wind velocity vector measuring device has a configuration including a reference signal generating unit 1, a transmitting unit 2, a transmission / reception switching unit 3, an electromagnetic wave transmitting / receiving unit 4, a receiving unit 5, a signal processing unit 6, and a beam scanning unit 7.
Next, the operation of the wind speed vector measuring device will be described.
The reference signal generator 1 generates a reference signal and inputs it to the transmitter 2. When this reference signal is input, the transmitter 2 generates a high-output transmission signal synchronized with the reference signal. The generated transmission signal is radiated from the electromagnetic wave transmission / reception unit 4 to the space via the transmission / reception switching unit 3. Here, when the wind velocity vector measuring device is realized by, for example, a light wave radar system, the laser beam is emitted from the electromagnetic wave transmitting / receiving unit 4. In the beam scanning unit 7, the radiation direction of the electromagnetic wave radiated from the electromagnetic wave transmitting / receiving unit 4 is controlled in a plurality of directions.

  The electromagnetic waves radiated to the space are reflected by the atmosphere. The reflected electromagnetic wave is received by the electromagnetic wave transmission / reception unit 4, and the reception signal is input to the reception unit 5 via the transmission / reception switching unit 3. The input received signal is amplified by an amplifier in the receiving unit 5 and then mixed with the reference signal input from the reference signal generating unit 1 to be extracted as a received low-frequency signal that has been frequency-converted to a low frequency band. It is. Since the radiation direction of the electromagnetic wave is controlled by the beam scanning unit 7, the received low-frequency signal can be obtained for a plurality of beam directions. A signal processing unit 6 performs signal processing on the received low-frequency signals obtained in a plurality of beam directions, and wind speed vectors are obtained. Any one of the wind speed vector calculating devices 61 to 64 of the present invention described below can be applied to the signal processing unit 6.

  1 is a block diagram showing a configuration of a wind speed vector calculating apparatus according to Embodiment 1 of the present invention. In the figure, the wind velocity vector calculation device 61 includes a Doppler velocity calculation unit 101, a spatial distribution propagation time estimation unit 102, a Doppler velocity time compensation unit 103, and a wind velocity vector calculation unit 104.

Next, the operation of the wind speed vector calculation device 61 will be described.
For the received low-frequency signal obtained by observation in a plurality of beam directions, the Doppler velocity calculation unit 101 converts the time series of the received low-frequency signal into a signal in the frequency domain, thereby performing Doppler of the target atmosphere. Get speed. For example, a Fourier transform technique is used for the conversion to the frequency domain. Based on the Doppler velocity calculated by the Doppler velocity calculation unit 101, the spatial distribution propagation time estimation unit 102 estimates a time during which the wind velocity spatial distribution propagates in the space (this is referred to as a space propagation time).

  The Doppler velocity time compensation unit 103 compensates by moving the time series time of the Doppler velocity obtained by each beam by a time corresponding to the estimated space propagation time. This compensation method is obtained from the received low-frequency signal of beam 2 when the spatial propagation time during which the wind speed spatial distribution propagates from beam 1 to beam 2 is t1, for example, when observation is performed in two beam directions. The time series of the Doppler speed is advanced by time t1. Alternatively, the Doppler velocity time series obtained from the received low frequency signal of beam 1 is delayed by time t1.

  The wind speed vector calculation unit 104 calculates a wind speed vector based on the Doppler speed after propagation time compensation for a plurality of beam directions. When the beam is continuously scanned in the azimuth direction, the VAD method may be used. Further, when the observation is performed with a small number of discrete beam directions, the wind speed vector may be calculated in the same manner as in the non-patent literature method.

  FIG. 3 is a block diagram showing the configuration of the spatial distribution propagation time estimation unit. In the figure, the spatial distribution propagation time estimation unit 102 includes a cross-correlation function calculation unit 111 and a peak detection unit 112. When the Doppler velocity calculated by the Doppler velocity calculation unit 101 is input, the cross-correlation coefficient calculation unit 111 selects Doppler velocity time-series data having a fixed time length from the two beam directions, The cross-correlation function of the time series data of the two selected Doppler velocities is calculated. The peak detection unit 112 detects the maximum value (peak) of the calculated absolute value of the cross-correlation function, and outputs the time difference at that time as the spatial propagation time of the wind speed spatial distribution.

The spatial distribution propagation time estimation unit 102 in FIG. 3 has described that the time difference at which the time-series cross-correlation function of the Doppler velocities of the beams in the two directions is maximized is used as the amount of time correction. However, when calculating the wind speed vector from the Doppler velocity observed in three or more beam directions, it is also necessary to perform time compensation of the Doppler velocity observed in a different beam direction from that used for calculating the cross-correlation function. There is. The configuration of the spatial distribution propagation time estimation unit applied in such a case is shown in FIG. In this configuration, a propagation time estimation unit 113 is added to the configuration of FIG.
In the propagation time estimation unit 113, it is assumed that the spatial propagation velocity of the wind velocity spatial distribution is uniform in the observation region, and the wind velocity spatial distribution in a beam direction different from that used for calculating the cross-correlation function by linear interpolation. Estimate the spatial propagation time of. As a result, even when the wind speed vector is calculated using Doppler velocities obtained in three or more beam directions such as the VAD method, it is possible to improve the wind speed vector calculation accuracy considering the space propagation time.

Furthermore, the structural example of another space distribution propagation time estimation part is shown in FIG. This configuration is obtained by adding a spatial propagation velocity calculation unit 114, a spatial propagation velocity averaging unit 115, and a spatial propagation time calculation unit 116 to the configuration of FIG. Here, the spatial propagation speed obtained by the combination of the two beam directions is calculated by the combination of a plurality of beams, and the average spatial propagation time in the entire space is obtained from the average value. Specifically, the spatial propagation velocity calculation unit 114 calculates the spatial propagation velocity based on the spatial propagation time and propagation distance obtained by the peak detection unit 112. The result of executing this processing for a plurality of beams in a combination of two beam directions is given to the spatial propagation speed averaging unit 115 and averaged to calculate an average spatial propagation speed. Assuming that the entire space propagates at this average space propagation speed, the space propagation time calculation unit 116 calculates the space propagation time of each beam. Because of this, in order to obtain the space propagation time using the Doppler velocity obtained with a large number of three or more beams, even if the accuracy of the Doppler velocity is reduced due to the influence of receiver noise, etc., the average effect It is possible to prevent degradation of the estimation accuracy of the space propagation time.
In general, the spatial propagation time of the wind speed spatial distribution varies depending on the spatial position. Therefore, it is preferable to compensate for the space propagation time in the first embodiment at every observation distance. However, when the spatial propagation time of the wind velocity spatial distribution can be approximated as uniform within the observation region, the spatial propagation time may be compensated with a constant value regardless of the observation distance.

  As described above, according to the first embodiment, the Doppler velocity of the atmosphere obtained by directing the beam in a plurality of different directions is calculated, and the spatial propagation time during which the calculated wind velocity spatial distribution propagates in the space. The time series of Doppler velocities obtained for each beam is compensated by moving the time series corresponding to the estimated spatial propagation time, and the wind speed vector based on the Doppler velocities after propagation time compensation for multiple beam directions. Is calculated. In particular, the spatial propagation time of the wind speed spatial distribution is estimated from the cross-correlation function of the time series of Doppler velocities observed in different beam directions, so that the effect of calculating the wind speed vector with high accuracy is obtained. It is done.

Embodiment 2. FIG.
In the first embodiment described above, estimation of the spatial propagation time of the wind speed spatial distribution from the time series cross-correlation functions of Doppler velocities observed in different beam directions has been described. Instead, in the second embodiment, the estimation of the space propagation time of the wind speed spatial distribution from the measured wind speed vector will be described. The wind speed vector calculating apparatus according to the second embodiment is the same as the configuration shown in FIG. 1, but the configuration of the spatial distribution propagation time estimation unit 102 is different from that of the first embodiment as shown in FIG. The spatial distribution propagation time estimation unit 102 includes a Doppler velocity time series smoothing unit 121, a provisional wind speed vector calculation unit 122, and a propagation time calculation unit 123.

Next, the operation of the spatial distribution propagation time estimation unit 102 in FIG. 6 will be described.
The Doppler velocity calculation unit 101 in FIG. 1 calculates the Doppler velocity of the atmosphere obtained by directing the beam in a plurality of different directions. The Doppler velocity time-series smoothing unit 121 performs Doppler before this propagation time compensation. Smooth the time series of speed in the time direction. For this process, for example, a moving average filter is used. The provisional wind speed vector calculation unit 122 calculates the provisional wind speed vector using the time-smoothed Doppler velocity that is the output of the Doppler velocity time series smoothing unit 121, and outputs it to the propagation time calculation unit 123. Although this temporary wind speed vector is not compensated for the propagation time of the wind speed spatial distribution, it is smoothed in the time direction by the Doppler speed time series smoothing unit 121, so that the temporary wind speed is sacrificed at the expense of time resolution. The vector calculation accuracy is prevented from deteriorating. When it is not necessary to consider the deterioration of the calculation accuracy of the temporary wind speed vector, the temporary wind speed vector calculation unit 122 calculates the temporary wind speed vector directly from the Doppler speed before the propagation time compensation of the Doppler speed calculation unit 101. It may be.

  Next, the propagation time calculation unit 123 calculates the space propagation time from the temporary wind speed vector. This space propagation time estimation method will be described with reference to FIG. It approximates that the wind speed spatial distribution propagates in the direction and speed represented by the provisional wind speed vector. A straight line passing through the observation point 1 and orthogonal to the tentative wind speed vector is referred to as a propagation plane 1, and a straight line passing through the observation point 2 and orthogonal to the tentative wind speed vector is referred to as a propagation plane 2. The propagation distance when the wind velocity spatial distribution propagates from observation point 2 to observation point 1 is the distance between propagation surface 1 and propagation surface 2. Therefore, the space propagation time of the wind speed spatial distribution from observation point 2 to observation point 1 is obtained by dividing this propagation distance by the magnitude of the provisional wind speed vector at observation point 2. Therefore, the spatial distribution propagation time estimation unit 102 calculates and outputs this spatial propagation time.

  As described above, according to the second embodiment, since the spatial propagation time of the wind speed space distribution is estimated from the provisional wind speed vector, since the cross correlation function is not calculated, the wind speed space is reduced with a small amount of calculation. It is possible to calculate the wind speed vector with high accuracy in consideration of the propagation time of the distribution. Further, since the time series of the Doppler speed is smoothed in the time direction, it is possible to prevent the deterioration of the provisional wind speed vector calculation accuracy, so that the effect of improving the accuracy of the finally obtained wind speed vector can be obtained.

Embodiment 3 FIG.
In the second embodiment, the provisional wind speed vector calculation unit 122 has been described using the Doppler speed before propagation time compensation to calculate the provisional wind speed vector. Instead, in this third embodiment, a description will be given of using the result of the wind speed vector calculated by the wind speed vector calculation unit 104 as it is as the temporary wind speed vector using the Doppler speed after propagation time compensation in the near past. FIG. 8 is a block diagram showing the configuration of the wind speed vector calculation apparatus according to the third embodiment. FIG. 9 is a block diagram showing details of the spatial distribution propagation time estimation unit according to the third embodiment. In these two figures, components corresponding to those in FIGS. 1 and 6 are denoted by the same reference numerals. The third embodiment is different from the second embodiment in how the constituent parts of the wind speed vector calculation device 62 are combined.

Next, the operation of the wind speed vector calculation device 62 will be described.
The wind speed vector after propagation time compensation obtained by the wind speed vector calculation unit 104 is input to the spatial distribution propagation time estimation unit 102. In the spatial distribution propagation time estimation unit 102, the input wind speed vector is used as a temporary wind speed vector, and the propagation time calculation unit 123 performs the spatial propagation time of the wind speed spatial distribution by the method described in FIG. Is estimated. The Doppler velocity time compensation unit 103 compensates the time series time of the Doppler velocity given from the Doppler velocity calculation unit 101 by this spatial propagation time. The wind speed vector calculation unit 104 calculates a final wind speed vector.

  The wind speed vector input to the spatial distribution propagation time estimation unit 102 as the provisional wind speed vector is the wind speed vector obtained by the wind speed vector calculation unit 104 at the immediately preceding time. Therefore, the loop composed of the three blocks of the spatial distribution propagation time estimation unit 102, the Doppler velocity time compensation unit 0103, and the wind speed vector calculation unit 104 is repeatedly executed, and the wind speed vector calculation accuracy can be improved.

Here, the case immediately after the start of observation will be described.
When the wind speed vector calculation unit 104 has not yet calculated the wind speed vector, since there is no output from the spatial distribution propagation time estimation unit 102, the propagation time is not input to the Doppler velocity time compensation unit 103. At such a stage, the Doppler speed time compensation unit 103 does not perform time compensation of the Doppler speed. As a result, the accuracy of the calculated wind speed vector is low at the time immediately after the start of observation, but since the time is compensated after the next time, a highly accurate wind speed vector is calculated. Absent. In addition, as described above, the loop processing composed of the three blocks of the spatial distribution propagation time estimation unit 102, the Doppler velocity time compensation unit 103, and the wind speed vector calculation unit 104 is repeatedly executed. In the above, it is possible to calculate a time-compensated highly accurate wind speed vector.

  As described above, according to the third embodiment, since the spatial propagation time of the wind speed spatial distribution is estimated from the wind speed vector obtained after the propagation time compensation, the accuracy of the spatial propagation time estimation is improved, The accuracy of the wind speed vector calculated using this also increases. Furthermore, the effect of further improving the wind speed vector calculation accuracy can be obtained by repeatedly performing the loop processing.

Embodiment 4 FIG.
In the first to third embodiments, correction of the space propagation time of the wind speed spatial distribution has been described. In the fourth embodiment, compensation of the spatial propagation direction of the wind speed spatial distribution will be described. FIG. 10 is a block diagram showing a configuration of a wind speed vector calculation apparatus according to Embodiment 4 of the present invention. In the figure, components corresponding to those in FIG. 1 are denoted by the same reference numerals. The wind velocity vector calculation device 63 includes a spatial distribution propagation direction estimation unit 202 in place of the spatial distribution propagation time estimation unit 102 of the wind velocity vector calculation device 61 in FIG. 1, and a Doppler velocity extraction unit in place of the Doppler velocity time compensation unit 103. 203.

Next, the operation of the wind speed vector calculation device 63 will be described.
The Doppler velocity calculation unit 101 obtains the target Doppler velocity of the atmosphere by converting the time series of the received low frequency signal into a frequency domain signal. For example, a Fourier transform technique is used for the conversion to the frequency domain. The spatial distribution propagation direction estimation unit 202 estimates the spatial propagation direction of the wind speed spatial distribution. The Doppler velocity extraction unit 203 extracts the Doppler velocity observed on a straight line parallel to the estimated spatial propagation direction. Specifically, as shown in FIG. 12, an observation point 1 is a point where one straight line parallel to the estimated spatial propagation direction intersects a line segment representing the observation direction 1, and an observation direction 2 where the same straight line is different. The point intersecting with the line segment to be represented is taken as observation point 2, and Doppler velocities at observation point 1 and observation point 2 are extracted. The wind speed vector calculation unit 104 calculates a wind speed vector based on the extracted Doppler speed.

  FIG. 11 is a block diagram illustrating a detailed configuration of the spatial distribution propagation direction estimation unit 202. In the figure, the spatial distribution propagation direction estimation unit 202 includes a wind direction axis cross-correlation function calculation unit 211 and a peak detection unit 212. FIG. 13 shows a situation where observation is performed in two beam directions, ie, direction 1 and direction 2 of observation. Here, it is assumed that the observation point 1 above the beam direction 1 is fixed and the spatial propagation direction is θ. When the intersection of the beam direction 2 and the straight line representing the spatial propagation direction is the observation point 2, the observation point 1 and the observation point 2 observe the same wind speed spatial distribution after a certain spatial propagation time. Actually, the spatial propagation direction θ is unknown. Accordingly, the wind direction axis cross-correlation function calculation unit 211 calculates the cross-correlation coefficient between the time series of the Doppler velocity at the observation point 1 and the time series of the Doppler velocity at the observation point 2 by changing the assumed θ. The cross-correlation coefficients calculated at different θ and collected as a function of θ are called wind direction cross-correlation functions. In other words, the wind direction axis cross-correlation function calculation unit 211 calculates the cross-correlation coefficient of Doppler velocities at the same time obtained in two different beam directions from the time series of Doppler velocities at the same or different distances depending on the beam direction. Thus, the wind direction axis cross-correlation function is obtained. The peak detecting unit 212 detects θ that maximizes the wind direction cross-correlation function, and outputs the θ, that is, the wind direction at the peak position, as the spatial propagation direction of the wind speed spatial distribution.

In FIG. 13, for example, when θ is 90 degrees, the wind speed spatial distribution does not propagate in the left and right directions in FIG. In this case, a combination of observation point 1 and observation point 2 such that the wind speed spatial distribution propagates from observation point 1 to observation point 2 or from observation point 2 to observation point 1 cannot be obtained. In such a case, no clear peak appears in the wind direction axis cross-correlation function. In this case, as in the conventional method, the Doppler velocities at the observation points 1 and 2 are extracted by the Doppler velocity extraction unit 203 so that the observation points 1 and 2 are at the same distance from the radar. The wind speed vector may be calculated by the vector calculation unit 104.
In the above description, only the compensation for the spatial propagation direction of the wind speed spatial distribution is performed. However, the compensation for the propagation time described in the first to third embodiments may be performed together.

  As described above, according to the fourth embodiment, when combining Doppler velocities in different beam directions, the distance at which the Doppler velocities are extracted in each beam direction is selected based on the spatial propagation direction of the wind velocity spatial distribution. Thus, the effect of improving the calculation accuracy of the wind speed vector can be obtained.

Embodiment 5 FIG.
In the fourth embodiment, it has been described that the spatial propagation direction of the wind speed spatial distribution is estimated from the time-series cross-correlation function of Doppler velocities observed in different beam directions. In the fifth embodiment, estimation of the spatial propagation direction of the wind speed spatial distribution from the measured wind speed vector will be described. The configuration of the wind speed vector calculation apparatus according to the fifth embodiment is the same as that of FIG. 10, but the spatial distribution propagation direction estimation unit 202 has a configuration as shown in FIG. In FIG. 14, the spatial distribution propagation direction estimation unit 202 includes a Doppler velocity time series smoothing unit 121, a provisional wind speed vector calculation unit 122, and a propagation direction extraction unit 223. Except for the propagation direction extraction unit 223, the configuration is the same as the configuration described in FIG.

Next, the operation of the spatial distribution propagation direction estimation unit 202 in FIG. 15 will be described.
The Doppler velocity time series smoothing unit 121 smoothes the time series of the Doppler velocity before propagation direction compensation input from the Doppler velocity calculation unit 101 in the time direction. The provisional wind speed vector calculation unit 122 calculates the provisional wind speed vector using the time-smoothed Doppler velocity that is the output of the Doppler velocity time series smoothing unit 121, and outputs it to the propagation direction extraction unit 223. The propagation direction extraction unit 223 regards the calculated temporary wind speed vector as the spatial propagation direction and outputs the vector to the Doppler velocity extraction unit 203. The Doppler speed extraction unit 203 extracts the Doppler speed observed on a straight line parallel to the direction of the provisional wind speed vector.
When it is not necessary to consider the deterioration of the calculation accuracy of the temporary wind speed vector, the temporary wind speed vector calculation unit 122 may calculate the temporary wind speed vector directly from the Doppler speed of the Doppler speed calculation unit 101.
In the above description, only the compensation relating to the spatial propagation direction of the wind speed spatial distribution is performed. However, the spatial propagation time compensation described in the first to third embodiments may be performed together.

  As described above, according to the fifth embodiment, since the cross-correlation function is not calculated, there is an effect that enables highly accurate calculation of the wind speed vector in consideration of the spatial propagation direction of the wind speed spatial distribution with a small amount of calculation. can get. Further, since the Doppler velocity time series is smoothed in the time direction, it is possible to prevent the deterioration of the provisional wind speed vector calculation accuracy, thereby obtaining the effect of improving the accuracy of the finally obtained wind velocity vector.

Embodiment 6 FIG.
In the fifth embodiment, the provisional wind speed vector calculation unit 122 has been described using the Doppler speed before the propagation direction compensation to calculate the provisional wind speed vector. Instead, in the sixth embodiment, a description will be given of using the result of the wind speed vector calculated by the wind speed vector calculation unit 104 using the Doppler speed after propagation direction compensation in the near past as a temporary wind speed vector. FIG. 15 is a block diagram showing a configuration of a wind speed vector calculation apparatus according to Embodiment 6 of the present invention. FIG. 16 is a block diagram showing the configuration of the spatial distribution propagation direction estimation unit according to the sixth embodiment. In the figure, components corresponding to those in FIGS. 10 and 14 are denoted by the same reference numerals. The sixth embodiment is different from the fifth embodiment in how the components are combined.

Next, the operation of the wind speed vector calculation device 64 will be described.
Here, the wind speed vector after propagation direction compensation obtained by the wind speed vector calculation unit 104 is input to the spatial distribution propagation direction estimation unit 202. In the spatial distribution propagation direction estimation unit 202, the input wind speed vector is used as the temporary wind speed vector, and the propagation direction calculation unit 223 outputs the direction of the temporary wind speed vector as the propagation direction of the wind speed spatial distribution. The Doppler speed extraction unit 203 extracts the Doppler speed as in the fourth embodiment, and the wind speed vector calculation unit 104 calculates the final wind speed vector.

  The wind speed vector input to the spatial distribution propagation direction estimation unit 202 as the provisional wind speed vector is the wind speed vector obtained by the wind speed vector calculation unit 104 at the immediately preceding time. Therefore, it is possible to improve the wind speed vector calculation accuracy by repeatedly executing a loop process including the three blocks of the spatial distribution propagation direction estimation unit 202, the Doppler speed extraction unit 203, and the wind speed vector calculation unit 104.

Here, the case immediately after the start of observation will be described.
At the stage where the wind speed vector calculation unit 104 has not yet performed the wind speed vector calculation, since there is no output from the spatial distribution propagation direction estimation unit 202, the propagation direction is not input to the Doppler velocity extraction unit 203. At such a stage, the Doppler velocity extraction unit 203 does not perform propagation direction compensation of the Doppler velocity. This reduces the accuracy of the calculated wind speed vector at the time immediately after the start of observation, but there is no problem because a highly accurate wind speed vector compensated for the spatial propagation direction is calculated after the next time. . Further, as described above, since the loop composed of the three blocks of the spatial distribution propagation direction estimation unit 202, the Doppler velocity extraction unit 203, and the wind speed vector calculation unit 104 is repeatedly executed, even at the time immediately after the start of observation. It is possible to calculate a time-compensated highly accurate wind speed vector.
In the above description, only the compensation regarding the propagation direction of the wind speed spatial distribution is performed. However, the compensation of the propagation time described in the first to third embodiments may be performed together.

  As described above, according to the sixth embodiment, since the spatial propagation direction of the wind speed spatial distribution is estimated from the wind speed vector obtained after propagation direction compensation, the accuracy of the propagation direction estimation is improved, The accuracy of the wind speed vector calculated by using this also becomes high. Furthermore, an effect of further improving the wind speed vector calculation accuracy can be obtained by performing iterative processing.

It is a block diagram which shows the structure of the wind speed vector calculation apparatus by Embodiment 1 of this invention. It is a block diagram which shows the structure of a typical wind speed vector measuring apparatus. It is a block diagram showing the structure of the spatial distribution propagation time estimation part which concerns on Embodiment 1 of this invention. It is a block diagram showing the structure of another space distribution propagation time estimation part which concerns on Embodiment 1 of this invention. It is a block diagram showing the structure of another spatial distribution propagation time estimation part based on Embodiment 1 of this invention. It is a block diagram showing the structure of the spatial distribution propagation time estimation part which concerns on Embodiment 2 of this invention. It is explanatory drawing which shows the method of estimating space propagation time from the provisional wind speed vector in Embodiment 2 of this invention. It is a block diagram which shows the structure of the wind speed vector calculation apparatus by Embodiment 3 of this invention. It is a block diagram showing the structure of the spatial distribution propagation time estimation part which concerns on Embodiment 3 of this invention. It is a block diagram which shows the structure of the wind speed vector calculation apparatus by Embodiment 4 of this invention. It is a block diagram showing the structure of the spatial distribution propagation direction estimation part which concerns on Embodiment 4 of this invention. It is explanatory drawing which shows the wind speed vector calculation method in Embodiment 4 of this invention. It is explanatory drawing shown about calculation of the wind direction axis cross correlation function in Embodiment 4 of this invention. It is a block diagram showing the structure of the spatial distribution propagation direction estimation part which concerns on Embodiment 5 of this invention. It is a block diagram which shows the structure of the wind speed vector calculation apparatus by Embodiment 6 of this invention. It is a block diagram showing the structure of the spatial distribution propagation direction estimation part which concerns on Embodiment 6 of this invention. It is explanatory drawing which shows the example of the conventional wind speed vector measurement. It is explanatory drawing which shows the shift | offset | difference of the time-axis direction of the wind speed change pattern which occurs in the measurement example of FIG.

Explanation of symbols

  101 Doppler velocity calculation unit, 102 Spatial distribution propagation time estimation unit, 103 Doppler velocity time compensation unit, 104 Wind speed vector calculation unit, 111 Cross correlation function calculation unit, 112 Peak detection unit, 113 Propagation time estimation unit, 114 Spatial propagation velocity calculation 115, space propagation speed averaging section, 116 space propagation time calculation section, 121 Doppler speed time series smoothing section, 122 provisional wind speed vector calculation section, 123 propagation time calculation section, 202 spatial distribution propagation direction estimation section, 203 Doppler speed extraction section 211 Wind direction axis cross-correlation function calculation unit 212 Peak detection unit 223 Propagation direction extraction unit

Claims (14)

A wind speed vector calculation device of a wind speed measuring device that radiates electromagnetic waves into space, receives electromagnetic waves reflected in the atmosphere, calculates a Doppler velocity by frequency analysis, and obtains a wind velocity from the Doppler velocity,
A Doppler velocity calculator that calculates the Doppler velocity of the atmosphere obtained by directing the beam in a plurality of different directions;
A spatial distribution propagation time estimation unit for estimating a spatial propagation time for the wind speed spatial distribution to propagate through the space based on the calculated Doppler velocity;
A Doppler velocity time compensation unit that compensates by moving a time series of Doppler velocity obtained by each beam calculated by the Doppler velocity calculation unit by a time corresponding to the estimated spatial propagation time;
A wind speed vector calculation device comprising: a wind speed vector calculation unit that calculates a wind speed vector based on a time series of Doppler velocities after propagation time compensation for a plurality of beam directions. The spatial distribution propagation time estimation unit
From the Doppler velocities calculated by the Doppler velocity calculation unit, select time-series data of Doppler velocities with a fixed time length for two different beam directions, and cross-correlate the time-series data of the two selected Doppler velocities. A cross-correlation function calculation unit for calculating a function;
The wind speed vector calculation apparatus according to claim 1, further comprising: a peak detection unit that detects a peak of the calculated cross-correlation function and outputs a time difference between the peaks as a spatial propagation time of the wind speed spatial distribution. The spatial distribution propagation time estimation unit
From the Doppler velocities calculated by the Doppler velocity calculation unit, select time-series data of Doppler velocities with a fixed time length for two different beam directions, and cross-correlate the time-series data of the two selected Doppler velocities. A cross-correlation function calculation unit for calculating a function;
A peak detector that detects a peak of the calculated cross-correlation function and outputs a time difference at the peak as a spatial propagation time of the wind speed spatial distribution;
Assuming that the propagation velocity of the wind velocity spatial distribution is uniform in the observation region, the propagation time for estimating and outputting the spatial propagation time of the wind velocity spatial distribution in a beam direction different from that used by the cross-correlation function calculation unit The wind speed vector calculation apparatus according to claim 1, further comprising: an estimation unit. The spatial distribution propagation time estimation unit
From the Doppler velocities calculated by the Doppler velocity calculation unit, select time-series data of Doppler velocities with a fixed time length for two different beam directions, and cross-correlate the time-series data of the two selected Doppler velocities. A cross-correlation function calculation unit for calculating a function;
A peak detector that detects a peak of the calculated cross-correlation function and outputs a time difference at the peak as a spatial propagation time of the wind speed spatial distribution;
A spatial propagation velocity calculation unit for calculating a spatial propagation velocity in a combination of two beam directions for a plurality of beams based on the spatial propagation time and the spatial propagation distance obtained by the peak detection unit;
A spatial propagation velocity averaging unit that calculates the average spatial propagation velocity by averaging the calculated spatial propagation velocity;
The wind velocity vector calculation apparatus according to claim 1, further comprising a space propagation time calculation unit that calculates a space propagation time of each beam from the calculated average space propagation velocity. The spatial distribution propagation time estimation unit
A provisional wind speed vector calculation unit that calculates a provisional wind speed vector based on a plurality of different Doppler velocities calculated in a Doppler velocity calculation unit;
Both observation points are obtained by dividing the distance between the two propagation planes by the magnitude of the provisional wind velocity vector, using the straight lines that pass through the observation points of the beams in the two directions and orthogonal to the calculated provisional wind velocity vector as propagation planes. The wind speed vector calculation apparatus according to claim 1, further comprising: a propagation time calculation unit that calculates a space propagation time of a wind speed spatial distribution propagating between the wind speeds. The spatial distribution propagation time estimation unit includes a velocity time series smoothing unit that smoothes a time series of Doppler velocities in a plurality of different beam directions calculated in the Doppler velocity calculation unit in the time direction,
6. The wind speed vector calculation device according to claim 5, wherein the temporary wind speed vector calculation unit calculates the temporary wind speed vector based on the Doppler speed after time smoothing obtained by the speed time series smoothing unit. A wind speed vector calculation device of a wind speed measuring device that radiates electromagnetic waves into space, receives electromagnetic waves reflected in the atmosphere, calculates a Doppler velocity by frequency analysis, and obtains a wind velocity from the Doppler velocity,
A Doppler velocity calculator that calculates the Doppler velocity of the atmosphere obtained by directing the beam in a plurality of different directions;
A spatial distribution propagation time estimation unit for estimating a spatial propagation time for the wind speed spatial distribution to propagate through the space based on the input wind speed vector;
A Doppler velocity time compensation unit that compensates by moving a time series of Doppler velocity obtained by each beam calculated by the Doppler velocity calculation unit by a time corresponding to the estimated spatial propagation time;
A wind speed vector calculating unit that calculates a wind speed vector based on a time series of Doppler velocities after propagation time compensation for a plurality of beam directions and uses the calculated wind speed vector as a wind speed vector to be input to the spatial distribution propagation time estimation unit . ,
Assuming that the spatial distribution propagation time estimation unit propagates the wind velocity spatial distribution at a velocity and direction that matches the input wind velocity vector, a propagation time calculation unit that calculates the spatial propagation time of the wind velocity spatial distribution in each beam direction A wind speed vector calculating device characterized by comprising:   8. The wind speed vector calculation apparatus according to claim 7, wherein a loop process including a spatial distribution propagation time estimation unit, a Doppler speed time compensation unit, and a wind speed vector calculation unit is repeated. A wind speed vector calculation device of a wind speed measuring device that radiates electromagnetic waves into space, receives electromagnetic waves reflected in the atmosphere, calculates a Doppler velocity by frequency analysis, and obtains a wind velocity from the Doppler velocity,
A Doppler velocity calculator that calculates the Doppler velocity of the atmosphere obtained by directing the beam in a plurality of different directions;
A spatial distribution propagation direction estimation unit for estimating a spatial propagation direction in which the wind velocity spatial distribution propagates in the space based on the calculated Doppler velocity;
Based on the estimated spatial propagation direction of the wind velocity spatial distribution and the Doppler velocity calculated by the Doppler velocity calculation unit, one straight line parallel to the spatial propagation direction is set, and the set straight line and a plurality of different observation directions A Doppler velocity extraction unit that extracts the Doppler velocity at the point where each intersects with each beam,
A wind speed vector calculation apparatus comprising: a wind speed vector calculation unit that calculates a wind speed vector from the extracted Doppler speed. Spatial distribution propagation direction estimation unit,
By calculating the cross-correlation coefficient of the Doppler velocities at the same time obtained in two different beam directions from the time series of Doppler velocities at the same or different distances depending on the beam direction, the wind direction cross-correlation function is obtained. A correlation function calculator;
10. A wind speed vector calculation according to claim 9, further comprising: a peak detection unit that detects a peak of the obtained wind direction axis cross-correlation function and outputs the wind direction at the peak position as a spatial propagation direction of the wind speed spatial distribution. apparatus. Spatial distribution propagation direction estimation unit,
A provisional wind speed vector calculation unit that calculates a provisional wind speed vector based on a plurality of different Doppler velocities calculated in a Doppler velocity calculation unit;
The wind speed vector calculation apparatus according to claim 9, further comprising: a propagation direction extraction unit that outputs the direction of the calculated temporary wind speed vector as a spatial propagation direction of the wind speed spatial distribution. The spatial distribution propagation direction estimation unit has a velocity time series smoothing unit that smoothes a time series of Doppler velocities in a plurality of different beam directions calculated in the Doppler velocity calculation unit in the time direction,
12. The wind speed vector calculation apparatus according to claim 11, wherein the temporary wind speed vector calculation unit calculates the temporary wind speed vector based on the Doppler speed after time smoothing obtained by the speed time series smoothing unit. A wind speed vector calculation device of a wind speed measuring device that radiates electromagnetic waves into space, receives electromagnetic waves reflected in the atmosphere, calculates a Doppler velocity by frequency analysis, and obtains a wind velocity from the Doppler velocity,
A Doppler velocity calculator that calculates the Doppler velocity of the atmosphere obtained by directing the beam in a plurality of different directions;
A spatial distribution propagation direction estimation unit for estimating a spatial propagation direction in which the wind speed spatial distribution propagates in the space based on the input wind speed vector;
Based on the estimated spatial propagation direction and the Doppler velocity calculated by the Doppler velocity calculation unit, a straight line parallel to the spatial propagation direction is set, and the set straight line and a plurality of different observation directions intersect. A Doppler velocity extraction unit that extracts the Doppler velocity of the point from each beam;
A wind speed vector calculating unit configured to calculate a wind speed vector from the extracted Doppler speed, and to input the calculated wind speed vector to the spatial distribution propagation direction estimating unit;
The wind velocity vector, wherein the spatial distribution propagation direction estimation unit includes a propagation direction calculation unit that outputs the input wind velocity vector as a temporary wind velocity vector and outputs the direction of the temporary wind velocity vector as a propagation direction of the wind velocity spatial distribution. Calculation device.   14. The wind speed vector calculation apparatus according to claim 13, wherein a loop process including a spatial distribution propagation direction estimation unit, a Doppler speed extraction unit, and a wind speed vector calculation unit is repeated.

Images