JP2002168948A - Device and method for processing signal in wind profiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a data acquiring rate in a wide altitude range. SOLUTION: This processor is provided with an FFT processing part 1 for Fourier-transforming a data of a received signal, an integration time setting part 5 for setting the optimum incoherent integration time in every altitude, an incoherent integration part 2 for calculating a power spectrum based on a Fourier-transformed data to time-integrate it by the set incoherent integration time, a Doppler speed calculating part 3 for detecting a peak of a signal spectrum based on the power spectrum to calculate a sight-line-directional speed of the atmosphere based on a Doppler frequency, and a quality control and time average processing part 4 for removing a data of low quality Doppler speed to conduct time-averaging.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal processing device and a signal processing method in a wind profiler for measuring a wind speed distribution in the sky.

[0002]

2. Description of the Related Art Wind direction and wind speed information is one of information necessary for weather forecast. The most common way to measure wind direction and speed is to install a wind direction and anemometer on the ground. However, in that case, only wind near the ground surface can be measured. In order to make the weather forecast more accurate, it is necessary to know the data on the wind direction and speed in the sky. for that reason,
Conventionally, the wind direction and speed of the sky have been measured using a sonde or the like. Observation using the sonde can only obtain data on the wind direction and speed at the time when the sonde was raised, so the time resolution of the observation was low for several hours or more.

On the other hand, in recent years, a technique for measuring the wind direction and speed in the sky using an atmospheric radar called a wind profiler has been established. With the wind profiler, it is possible to measure the wind direction and speed over the sky every one to several minutes. It is expected that data on the wind direction and speed in the sky with such a high time resolution will be effective in improving the accuracy of weather forecasts. For such a wind profiler, see, for example, Carter et al. , D
development in UHF lower t
roposheric wind profiling
at NOAA's Aeronomic Labor
attory, Radio Science, vo
l. 30, no. 4, pp. 97-1001, 1
995. There is a thing introduced in.

Here, the principle of measuring the atmosphere with a wind profiler will be described. A wind profiler is a type of Doppler radar, and generally, as shown in FIG.
Antenna 101, transmitting / receiving device 102, signal processing device 10
3. Wind speed vector calculation device 104, display / recording device 10
5. In the wind profiler configured as described above, a reflected wave of an electromagnetic wave radiated from the antenna 101 into the air is received by the antenna 101, and the received electromagnetic wave is amplified, frequency-converted, and detected by the transmission / reception device 102, and is converted into a video signal. Is converted to A frequency analysis process is performed on the video signal by the signal processing device 103 to calculate a Doppler frequency, calculate a Doppler speed from the Doppler frequency, send the calculated Doppler speed to the wind speed vector calculation device 104, and display the calculated wind speed vector there.
The information is displayed or recorded on the recording device 105.

[0005] In the above-mentioned conventional wind profiler, as the signal processing device 103, for example, one having a configuration as shown in FIG. 14 is generally used. In FIG. 14, 1 is an FFT processing unit, 2 is an incoherent integration unit, 3 is a Doppler velocity calculation unit, and 4 is a quality management / time averaging processing unit.

Next, the operation will be described. The data of the received signal output from the transmission / reception device 102 is input to the FFT processing unit 1. The FFT processing unit 1 performs a Fourier transform on the data of the received signal. The data of the received signal after the Fourier transform is input to the incoherent integrator 2. Here, after calculating a power spectrum obtained by obtaining a power value from the Fourier transform of the data of the received signal, a process of integrating the power spectra obtained at a plurality of times, that is, a process of incoherent integration is performed. In the power spectrum of the data of the received signal,
The spectrum of the atmospheric turbulence echo, that is, the signal spectrum and the noise spectrum are included. By this incoherent integration processing, the fluctuation width of the noise component and the fluctuation width of the signal component are reduced. Therefore, the accuracy of signal detection can be increased by performing incoherent integration. However, since the incoherent integration uses data at a plurality of times, the time resolution is reduced.

The Doppler velocity calculator 3 detects the peak of the signal spectrum from the stabilized power spectrum after incoherent integration, calculates the average Doppler frequency from the center Doppler frequency, and furthermore, calculates the Doppler frequency. , The gaze direction velocity of the atmospheric turbulence as the target is calculated.

However, the wind speed directly measured by the Doppler radar is only a projection component of the actual wind speed in the line of sight. Therefore, the wind speed vector calculation device 104 performs measurement by changing the observation direction of the radar in a plurality of directions, assuming that the wind speed distribution in a certain area above the radar is uniform, thereby obtaining a three-dimensional wind speed vector. Perform synthesis.

In such a wind profiler, the incoherent integration time is constant regardless of the altitude. However, the radar reflectivity of atmospheric turbulence, which is the target of the wind profiler, sharply decreases with increasing altitude, so that the optimum integration time actually varies with altitude. In other words, a higher altitude where the SN ratio is lower requires a longer integration time than a lower altitude where the SN ratio is higher.

Further, since the wind speed at a high altitude is not greatly affected by the ground surface, the time change of the wind speed is smaller than that at a low altitude. For this reason, it is advantageous to increase the incoherent integration time at high altitudes.

As described above, the optimum value of the incoherent integration time of the wind profiler differs depending on the altitude.

[Problems to be solved by the invention]

Since the signal processing device in the conventional wind profiler is configured as described above, the incoherent integration time is constant irrespective of the altitude, and the incoherent integration time is insufficient at high altitudes. There has been a problem that the detection performance cannot be obtained and the data acquisition rate decreases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and a wind profiler in which an incoherent integration time is set in accordance with altitude to improve a data acquisition rate in an altitude range as wide as possible. It is an object of the present invention to obtain a signal processing device and a signal processing method.

[0014]

A signal processing device in a wind profiler according to the present invention includes a Fourier transform processing unit for performing a Fourier transform on data of a received signal, and an integration time for setting an optimum incoherent integration time for each altitude. A setting section, an incoherent integrator that calculates a power spectrum from the Fourier-transformed data, and time-integrates the power spectrum for a set incoherent integration time; detects a peak of the signal spectrum from the power spectrum; A Doppler velocity calculator that calculates the line-of-sight velocity of the atmosphere from the frequency, and a quality control / time averaging processor that removes low-quality Doppler velocity data and averages the time, and measures the wind velocity It is.

In the signal processing device of the wind profiler according to the present invention, the incoherent integration time is set to be short at a low altitude and long at a high altitude.

In the signal processing device in the wind profiler according to the present invention, the integration time setting unit calculates the data acquisition ratio from the Doppler speed data output from the Doppler speed calculation unit according to the data acquisition ratio from the data acquisition ratio calculation unit. Thus, the incoherent integration time is set.

In the signal processing device in the wind profiler according to the present invention, the integration time setting section obtains data from a data acquisition rate calculation section that calculates a data acquisition rate from Doppler velocity data output from the quality control / time average processing section. The incoherent integration time is set according to the rate.

In the signal processing device in the wind profiler according to the present invention, the incoherent integration time at each altitude is determined by the integration time setting section based on the data acquisition rate at the altitude calculated by the data acquisition rate calculation section. It is something to set.

In the signal processing device in the wind profiler according to the present invention, the incoherent integration time for each of the divided altitude ranges is calculated by the integration time setting unit. This is set based on the data acquisition rate for each range.

In the signal processing device in the wind profiler according to the present invention, the data interpolation processing section interpolates data in the time direction with respect to the altitude at which the incoherent integration time is set to be long, and has a constant time resolution regardless of the altitude. The Doppler speed is output to a quality control / time average processing unit.

The signal processing device in the wind profiler according to the present invention performs the time averaging process by the quality control / time averaging processing unit using the number of data inversely proportional to the incoherent integration time, and the time resolution of the data varies depending on the altitude. The output is a constant Doppler speed.

According to the signal processing device in the wind profiler according to the present invention, the update width of the integration range in the time direction of the incoherent integration is fixed regardless of the incoherent integration time, and the time of the data after integration from the incoherent integration unit is The resolution is fixed regardless of the altitude.

The signal processing method in the wind profiler according to the present invention reads the data of the received signal, performs a Fourier transform, sets an incoherent integration time for each altitude, and calculates a power spectrum from the Fourier transformed data. , Performs incoherent integration for the set incoherent integration time, detects the signal spectrum from the power spectrum after the incoherent integration, calculates the Doppler velocity from the Doppler frequency, and calculates the total altitude with respect to the time to be processed. If the processing of the data has not been completed, the altitude of the processing target is updated to the next altitude, the processing is returned to the setting of the incoherent integration time, and if completed, the time of the processing target is set to the next time By proceeding and initializing the altitude to be processed, returning the processing to reading data Te, in which to perform the measurement of the wind speed.

In the signal processing method in the wind profiler according to the present invention, the data of the received signal is read and subjected to a Fourier transform, an initial value of an incoherent integration time is set, and a power spectrum is calculated from the Fourier transformed data. The incoherent integration is performed for the set incoherent integration time, the signal spectrum is detected from the power spectrum after the incoherent integration, the Doppler velocity is calculated from the Doppler frequency, and the processing target is obtained from the Doppler velocity. By calculating the altitude data acquisition rate, if the data acquisition rate is less than a predetermined threshold and if the incoherent integration time is less than the upper limit, increase the setting of the incoherent integration time. , Return to the process of incoherent integration, In this case, confirm that processing of data at all altitudes for the time being processed has been completed, and if not completed, update the altitude to be processed to the next altitude and then perform incoherent integration. Return the processing to the time setting, advance the time of the processing target to the next time if completed, measure the wind speed by initializing the altitude to be processed, and return the processing to data reading It is like that.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a signal processing device in a wind profiler according to Embodiment 1 of the present invention. The overall configuration of the wind profiler is the same as that of the conventional case shown in FIG. 13, and the signal processing device 103 shown in FIG. 1 forms a part of the wind profiler shown in FIG.

In FIG. 13, reference numeral 101 denotes an antenna for transmitting and receiving electromagnetic waves, and reference numeral 102 denotes a transmitting and receiving device for performing input / output processing of electromagnetic waves transmitted and received by the antenna 101. 10
Reference numeral 3 denotes a signal processing device according to Embodiment 1 of the present invention, the configuration of which is shown in FIG. Reference numeral 104 denotes a wind speed vector calculation device that synthesizes a three-dimensional wind speed vector from the output of the signal processing device 103. Reference numeral 105 denotes a display / recording device that displays or records the calculation result of the wind speed vector calculation device 104.

In FIG. 1, reference numeral 1 denotes a transmitting / receiving device 10.
2 is a Fourier transform processing unit for performing a Fourier transform on the data of the received signal received in 2, and here, for example, an FFT processing unit for performing a fast Fourier transform (FFT) is used. Reference numeral 2 denotes an incoherent integration unit that calculates a power spectrum from the data of the received signal that has been Fourier-transformed and output by the FFT processing unit 1 and collects and integrates the power spectra obtained at a plurality of times. Reference numeral 3 denotes a Doppler velocity calculating unit that detects a signal spectrum from the power spectrum output from the incoherent integrator 2 and calculates the Doppler velocity of the target from the center frequency, that is, the line-of-sight velocity of the target. Reference numeral 4 denotes a quality management / time averaging processing unit that removes data of reduced quality from the Doppler speed data calculated by the Doppler speed calculation unit 3, averages the time, and outputs the result to the wind speed vector calculation device 104. . An integration time setting unit 5 sets an incoherent integration time according to the altitude, and instructs the incoherent integration unit 2 of the integration time.

Next, the operation will be described. In the wind profiler configured as shown in FIG. 13, the electromagnetic wave generated by the transmitting / receiving device 102 is radiated from the antenna 101 into the air. Electromagnetic waves radiated into the air are reflected by the density of the refractive index of the atmosphere as scatterers. The reflected electromagnetic wave is received by the antenna 101 and input to the transmitting / receiving device 102. When the scatterer is flowing with the wind above, the frequency of the received electromagnetic wave changes due to the Doppler effect. By detecting the change in the frequency in the same manner as a general Doppler radar, the wind speed in the sky is measured. Specifically, the transmitting and receiving device 102 converts the received electromagnetic wave into a video signal by performing amplification, frequency conversion, and detection of the electromagnetic wave,
It is output to the signal processing device 103. Signal processing device 1
In 03, a Doppler frequency is calculated by performing a frequency analysis process on the video signal. Further, the Doppler speed is calculated from the Doppler frequency.

A detailed processing operation of the signal processing device 103 according to the first embodiment will be described below. The data of the received signal output from the transmitting / receiving apparatus 102 shown in FIG. 13 is input to the FFT processing unit 1 in FIG. 1 and subjected to Fourier transform. The data of the received signal that has been Fourier-transformed by the FFT processing unit 1 is input to the incoherent integration unit 2. The incoherent integrator 2 calculates the power spectrum by calculating the square of the absolute value of the amplitude for each frequency. The incoherent integrator 2 further collects power spectra calculated from data at a plurality of times and integrates them. The number of data in the time direction to be integrated in the integration process is determined by the integration time set for each altitude in the integration time setting unit 5.

The power spectrum after the incoherent integration is input from the incoherent integrator 2 to the Doppler velocity calculator 3. The Doppler velocity calculator 3 detects the peak of the signal spectrum from the stabilized power spectrum after the incoherent integration, calculates the average Doppler frequency from the center Doppler frequency, and further converts the Doppler frequency to the Doppler velocity. By doing so, the gaze direction velocity of the atmospheric turbulence as the target is calculated.

However, the wind speed directly measured by the Doppler radar is only the projected component of the actual wind speed in the line of sight. Therefore, assuming that the wind speed distribution in a certain area above the radar is uniform, measurements are performed while changing the observation direction of the radar in a plurality of directions, and the wind speed vector calculation device 104 synthesizes it into a three-dimensional wind speed vector. I do.

The principle of calculating the three-dimensional wind velocity vector is shown in FIG.
This will be described with reference to FIG. FIG. 2A shows an example of a beam direction in a wind profiler. In this example, the beam is observed in the zenith and in a total of five directions: east, west, south, and north. The zenith angle of the beam other than the zenith direction is, for example, 1
It is set to about 0 degrees. The three-dimensional wind vector can be divided into an east-west component, a north-south component, and a vertical component. The vertical component is the Doppler velocity itself obtained with a beam directed in the zenith direction (hereinafter referred to as a zenith beam). The east-west component can be obtained using the Doppler velocity of the beam directed in the east direction (hereinafter referred to as the east beam, the same applies to other directions) and the Doppler velocity of the west beam.

FIG. 2 (b) shows what Doppler velocities are observed in the east beam and the west beam when the wind is blowing horizontally in the east-west direction. As shown in the figure, when the wind is blowing from the west to the east, the approaching Doppler velocity is observed in the west beam, and the approaching Doppler velocity is observed in the east beam. Thus, observing the same wind in different beam directions will result in different Doppler velocities. Therefore, it is possible to calculate the horizontal wind component from the difference in Doppler velocity between the beams. Similarly, the north-south component of the wind speed can be calculated by using the north beam and the south beam.

FIG. 3 is an explanatory diagram schematically showing the power spectrum of the data of the received signal observed by the wind profiler. When the SN ratio is high, the peak of the signal spectrum can be easily detected.
As the ratio becomes smaller, the peak value of the signal spectrum becomes lower, making it difficult to distinguish from noise fluctuation. The integration by the incoherent integrator 2 has the effect of reducing the statistical fluctuation of noise and signal. Therefore, if the incoherent integration time is increased by the integration time setting unit 5,
The standard deviation of the noise power density shown in FIG.
Even when the N ratio is small and the peak value of the signal spectrum is low, the peak of the signal spectrum can be detected.

The Doppler velocity calculator 3 detects the peak of the atmospheric turbulence echo from the power spectrum in this manner,
From the center Doppler frequency, the Doppler velocity of the atmospheric turbulence echo, that is, the line-of-sight direction wind velocity is obtained. The line-of-sight direction wind speed output from the Doppler speed calculation unit 3 is subjected to time averaging processing after removing low-quality data in the quality management / time averaging processing unit 4 and output to the wind speed vector calculation device 104. The wind speed vector calculation device 104 synthesizes data observed in different beam directions to obtain a 3
Calculate the dimensional wind speed vector. The calculation result of the wind speed vector calculation device 104 is sent to the display / recording device 105 to be displayed or recorded.

The integration time setting section 5 sets an optimum incoherent integration time for each altitude. In the low altitude range, the radar and the target are close, and the atmospheric concentration is high, so that the reflectance of electromagnetic waves due to atmospheric turbulence is high. Therefore, a received signal having a relatively high SN ratio is observed. Therefore, even if the incoherent integration time is short, the signal spectrum can be easily detected from the power spectrum. In addition, low-altitude winds are easily affected by the ground surface, and time changes in wind direction and speed occur in a short time. Therefore, it is desirable to measure the three-dimensional wind velocity vector with high time resolution. Even when performing time averaging processing after incoherent integration, or when a peculiar wind occurs only at a certain time affected by the ground surface, if the wind velocity vector is obtained with high time resolution, the peculiar wind velocity The average wind speed can be obtained by using only the wind speed vector data which is removed by the quality control process and has a prominent tendency.

On the other hand, in the high altitude range, the distance between the radar and the target is large, and the atmospheric concentration becomes thin, and the electromagnetic wave reflectance of atmospheric turbulence sharply decreases, so that the SN ratio of the received signal decreases. There are many. Therefore, in order to accurately detect the signal spectrum, it is necessary to increase the number of incoherent integrals and reduce the fluctuation of the power spectrum. At high altitudes, the wind does not receive much influence from the ground surface, so that the time change of the wind speed vector is small. Therefore, even if the time resolution of the wind speed vector calculation is lower than that at the low altitude, there is not much problem.

From the above, it is generally considered that making the incoherent integration time short at low altitudes and long at high altitudes is an appropriate signal processing method. A typical example is shown in FIG. This figure shows that the incoherent integration time is 1 minute in altitude range 1 which is low altitude, 5 minutes in altitude range 2 which is medium altitude, and 10 minutes in altitude range 3 which is high altitude. I have.

Hereinafter, the operation of the signal processing device 103 will be described in detail with reference to the flowchart shown in FIG. First, in the data reading step ST1,
Data of a reception signal from the transmission / reception device 102 is input to the signal processing device 103. The signal processing device 103 performs a fast Fourier transform on the input received signal data in a Fourier transform step (hereinafter referred to as an FFT step) ST2. Next, the process proceeds to an integration time setting step ST3, in which an incoherent integration time for each altitude is set.
Next, in the incoherent integration step ST4, F
The power spectrum is calculated from the Fourier transform of the received signal data obtained in the FT step ST2, and the incoherent integration is performed for the incoherent integration time set in the integration time setting step ST3.

Next, in a Doppler velocity calculation step ST5, a signal spectrum is detected from the power spectrum after the incoherent integration calculated in the incoherent integration step ST4, and a Doppler velocity is calculated from the Doppler frequency. Thereafter, it is determined in the all-altitude processing end determination step ST6 whether or not data of all altitudes has been processed for the data at the time to be processed. If the result of the determination is that processing for all altitudes has not been completed, the process proceeds to the altitude update step ST7, where the altitude to be processed is updated to the next altitude, and the process returns to the integration time setting step ST3. On the other hand, if the processing has been completed for all altitudes, the time to be processed is advanced to the next time in the time updating step ST8, the altitude to be processed is initialized, and the processing is performed in the data reading step ST8.
Return to 1.

The quality control / time averaging processing section 4 performs quality control processing and time averaging processing. This quality control process is a process for removing data that is judged to have deteriorated in quality. Assuming continuity of data in a certain time and space range, it is possible to remove discontinuous data and improve quality. Only high data is left.

When removing discontinuous data in the quality control / time averaging processing unit 4, the conventional quality control processing assumes that data can be obtained at the same time resolution at all altitudes, or There may be a processing scheme in which it is desirable to have the same time resolution at all altitudes. In such a case, it is also considered effective that the quality control / time average processing unit 4 performs interpolation processing on the input Doppler velocity data.

FIG. 6 shows an example of the configuration of the signal processing device of the wind profiler according to the first embodiment of the present invention in which such data interpolation processing is performed. In the figure, reference numeral 6 denotes a data interpolation processing unit that performs an interpolation process on the Doppler speed data input from the Doppler speed calculation unit 3 and outputs the data to the quality control / time average processing unit 4.

The data interpolation processing unit 6 performs data interpolation at other altitudes in the time direction so as to have the same time resolution as the altitude having the highest time resolution in the entire altitude range. For example, if only one piece of data exists in the time direction in the time range in which the quality control process is performed by extending the incoherent integration time, the same wind speed value may be assumed at all interpolation points.

As described above, according to the first embodiment, since the incoherent integration time is set for each altitude, an appropriate time resolution and detection can be performed according to the characteristics of the target for each altitude. The effect that highly accurate signal processing can be realized is obtained.

Since the incoherent integration time is set to be short at low altitudes and long at high altitudes, wind speed vectors are measured with high time resolution at low altitudes close to the ground surface, and the SN ratio is reduced. The effect that the detection accuracy can be improved even at an altitude is also obtained.

Further, by combining the data interpolation processing, even when the incoherent integration time differs for each altitude, there is obtained an effect that the time resolution of the output Doppler velocity is constant regardless of the altitude.

If Doppler speed data or wind speed data is obtained at the same time interval at all altitudes, the data will be used in the secondary use of wind speed data, including the use of wind speed data as an initial value for numerical weather prediction. Can be output in an easy-to-use form.

Embodiment 2 Here, since the state of the atmosphere changes depending on the weather, the optimal incoherent integration time changes with time. In the first embodiment described above, the incoherent integration time is determined in advance for each altitude. However, the incoherent integration time may be adaptively set for each altitude according to the state of the atmosphere. The second embodiment relates to a signal processing device and a signal processing method in a wind profiler that adaptively sets an incoherent integration time for each altitude according to the state of the atmosphere.

FIG. 7 is a block diagram showing a signal processing device of such a wind profiler according to the second embodiment of the present invention. In the figure, 103 is a signal processing device,
1 is an FFT processing unit, 2 is an incoherent integration unit, 3 is a Doppler velocity calculation unit, 4 is a quality control / time average processing unit,
Reference numeral 5 denotes an integration time setting unit, which is the same as that shown in FIG. Reference numeral 7 denotes a data acquisition rate calculation unit that inputs the Doppler velocity data output from the Doppler velocity calculation unit 3 to calculate a data acquisition rate, and inputs the data acquisition rate to the integration time setting unit 5. Note that the integration time setting unit 5 includes a data acquisition rate calculation unit 7
1 in that the incoherent integration time is set based on the data acquisition rate calculated in (1).

Next, the operation will be described. Here, in the signal processing device 103 having the configuration shown in FIG.
Fourier transform of the data of the received signal by the processing unit 1, incoherent integration by the incoherent integration unit 2, detection of the signal spectrum by the Doppler speed calculation unit 3, calculation of the Doppler speed, and the time of the Doppler speed by the quality control / time averaging processing unit 4. For each average process, the same operation as in the first embodiment shown in FIG. 1 is performed. A characteristic of the second embodiment is that the integration time setting unit 5 sets the incoherent integration time based on the data acquisition rate calculated by the data acquisition rate calculation unit 7.

Each altitude calculated by the Doppler velocity calculator 3,
The Doppler velocity for each beam is input to the data acquisition rate calculation unit 7 together with the quality control / time average processing unit 4.
The Doppler speed obtained by this Doppler speed calculation unit 3 is
When the signal spectrum is not detected due to a decrease in the SN ratio, the altitude and the Doppler velocity of the beam are lost. The data acquisition rate calculation unit 7 calculates, from the Doppler velocity data from the Doppler velocity calculation unit 3, the ratio of non-missing data to all data as the data acquisition rate. This data acquisition rate can be calculated from data at a plurality of times for each altitude and each beam.

In order to calculate the data acquisition rate from the data at one time, the observation altitude range is divided into several altitude ranges, and the data acquisition rate is calculated from the data within the altitude range. Good. In this case, the data acquisition rate is calculated by the data acquisition rate calculation unit 7 for each of the altitude ranges divided in advance, and the altitude divided in advance by the integration time setting unit 5 is calculated based on the data acquisition rate for each of the altitude ranges. Set the incoherent integration time for each range.

The data acquisition rate calculated by the data acquisition rate calculation section 7 is input to the integration time setting section 5. The integration time setting unit 5 increases the incoherent integration time at an altitude where the acquisition rate is lower than a preset threshold value, so that the integration time becomes larger than a standard value. The threshold for the data acquisition rate may be the same at all altitudes, or different thresholds may be used for altitudes.

Hereinafter, the operation of the signal processing device 103 will be described in detail with reference to the flowchart shown in FIG. First, in a data reading step ST10, data of a received signal output from the transmitting / receiving apparatus 102 is input to the signal processing apparatus 103, and in the FFT step ST11, fast Fourier transform is performed on the input received signal data. Next, integration time initial value setting step ST12
To set the initial value of the incoherent integration time. Next, in incoherent integration step ST13,
The power spectrum is calculated from the data of the Fourier-transformed received signal obtained in the FFT step ST11, and the incoherent integration is performed for the incoherent integration time set in the integration time initial value setting step ST12.

Next, in a Doppler velocity calculation step ST14, a signal spectrum is detected from the power spectrum after the incoherent integration calculated in the incoherent integration step ST13, and a Doppler velocity is calculated from the Doppler frequency. Next, the process proceeds to the data acquisition rate calculation step ST15, where the Doppler speed calculation step ST15 is performed.
From the Doppler velocity calculated in step 14, the data acquisition rate of the altitude that is currently being processed is calculated. Thereafter, in a data acquisition rate determination step ST16, the data acquisition rate calculated in the data acquisition rate calculation step ST15 is compared with a predetermined threshold value.

As a result of the comparison, if the data acquisition rate of the Doppler velocity is lower than the threshold value, the integration time determination step ST
If the Doppler velocity is obtained at a data acquisition rate equal to or higher than the threshold, the flow proceeds to the all-altitude processing end determination step ST19 described later. Integration time determination step ST
In 17, it is determined whether or not the current incoherent integration time exceeds a predetermined incoherent integration time (upper limit). If the current incoherent integration time exceeds the upper limit, the total altitude described later is determined. The process proceeds to the processing end determination step ST19, and otherwise proceeds to the integration time increasing step ST18. In this integration time increasing step ST18, the setting of the incoherent integration time is increased, and then the incoherent integration step ST18 is performed.
The process returns to step 13.

In addition, the all-altitude processing end determination step S
At T19, it is determined whether or not data at all altitudes has been processed for the data at the time to be processed. If the result of the determination is that processing for all altitudes has not been completed, the process proceeds to the altitude update step ST20, where the altitude to be processed is updated to the next altitude, and the process returns to the integration time initial value setting step ST12. On the other hand, if the processing has been completed for all altitudes, the time to be processed is advanced to the next time in the time updating step ST21, the altitude to be processed is initialized, and the process returns to the data reading step ST10.

The above processing steps are supplemented by describing the number of data and the integration time more specifically. The data of the received signal input in the data reading step ST10 has a data amount for a time equal to the upper limit of the incoherent integration time. Here, the upper limit of the incoherent integration time is defined as Tmax. In FFT step ST11, Fourier transform is performed on the data divided by the FFT points in the time direction at each altitude. Next, integration time initial value setting step ST1
In step 2, an initial value of the incoherent integration time, which is the minimum value of the incoherent integration time, is set.

Next, an incoherent integration step ST1
In step 3, the Fourier-transformed data is collected for each incoherent integration time, and incoherent integration is performed.
Now, assuming that the incoherent integration time is Ti,
Tmax / Ti power spectra after incoherent integration for one altitude are obtained. A signal spectrum peak is detected from each power spectrum, and the Doppler speed is calculated in a Doppler speed calculation step ST14. At this time, the maximum Tmax / Ti Doppler velocities are calculated. However, since the signal spectrum may not be detected when the SN ratio is low, the actually obtained Doppler velocity is smaller than Tmax / Ti.

Therefore, the data acquisition rate calculation step ST1
In 5, the data acquisition rate of the altitude currently focused on is calculated. Next, in a data acquisition rate determination step ST16, the data acquisition rate is compared with a threshold value. If the data acquisition rate is larger than a preset threshold value, the flow proceeds to the all-altitude processing end determination step ST19. Conversely, if the data acquisition rate is smaller than the threshold, the integration time determination step ST
At 17, it is confirmed that the current incoherent integration time does not exceed the upper limit. If it is confirmed that the value does not exceed the upper limit, the incoherent integration time is increased in the integration time increasing step ST18, and the process returns to the incoherent integration step ST13 to repeat the processing from the incoherent integration. Thereafter, the processing from the incoherent integration step ST13 to the integration time increasing step ST18 is repeated until the data acquisition rate of the altitude being processed exceeds the threshold value or the incoherent integration time exceeds the upper limit.

While the processing flow for calculating the data acquisition rate for each altitude has been described above, when calculating the data acquisition rate for each altitude range, the FFT step ST
11 to the integration time increasing step ST18
The process is performed for each altitude range, and the altitude is updated in units of the altitude range in the altitude update step ST20. In this case, since the correction processing of the incoherent integration time is performed for each altitude range, the processing is simplified as compared with setting the incoherent integration time for each altitude, and the load of signal processing can be reduced. it can.

In the description of the second embodiment, the calculation of the data acquisition rate is performed using the Doppler velocity data output from the Doppler velocity calculation unit 3. The Doppler velocity after time averaging output from the processing unit 4 may be input to the data acquisition rate calculation unit 7 to calculate the data acquisition rate. FIG. 9 is a block diagram showing a signal processing device in a wind profiler having such a configuration. In this case, the data input to the data acquisition rate calculation unit 7 is performed not from the Doppler speed calculation unit 3 but from the quality management / time averaging processing unit 4, and the other points are the same as those in FIG. 7.

Also in the second embodiment, as in the first embodiment, a data interpolation processing unit 6 is provided between the Doppler speed calculation unit 3 and the quality control / time averaging processing unit 4. Interpolation processing may be performed on the Doppler velocity data input from the Doppler velocity calculation unit 3 to output a Doppler velocity having a constant time resolution to the quality control / time averaging processing unit 4 regardless of the altitude.

As described above, according to the second embodiment, an appropriate incoherent integration time can be set adaptively even when the data acquisition rate changes due to a change in weather conditions. Since the performance of signal processing can always be kept in an optimum state, and even if the characteristics of the wind over the sky differ depending on the observation site, the incoherent integration time is automatically set in the second embodiment. Effects such as easy signal processing setting at the time of installation are obtained.

Embodiment 3 In the above embodiments, since the incoherent integration time differs for each altitude,
The time interval of the finally obtained wind speed data may vary depending on the altitude, but when using the data for weather forecast, etc., it is more convenient to obtain the wind speed data at the same time interval at all altitudes. It is thought that there are many cases. Therefore, the difference in the time resolution of the data after incoherent integration should be absorbed by the difference in the number of time averages when performing time averaging so that the wind speed data is output at the same time interval at all altitudes. Is also conceivable. The third embodiment relates to a signal processing device in such a wind profiler.

FIG. 10 shows a third embodiment of the present invention.
FIG. 9 is a block diagram showing a signal processing device of such a wind profiler, in which parts corresponding to the respective parts of the second embodiment are denoted by the same reference numerals as in FIG. 7 and description thereof is omitted. In the figure, 8 receives the incoherent integration time at each altitude output from the integration time setting unit 5, sets the number of data inversely proportional to the incoherent integration time as a time average number at each altitude, and performs quality control / time It is an altitude hourly average number setting unit that instructs the averaging unit 4 of the time average number of each altitude.

Next, the operation will be described. Here, in the signal processing apparatus 103 shown in FIG. 10, Fourier transform of the data of the received signal by the FFT processing unit 1, incoherent integration by the incoherent integration unit 2, detection of the signal spectrum by the Doppler velocity calculation unit 3, and Doppler The processing of the speed calculation, the calculation of the data acquisition rate by the data acquisition rate calculation unit 7, and the setting of the incoherent integration time for each altitude by the integration time setting unit 5 are the same as those in the second embodiment shown in FIG. Operation. The feature of the third embodiment is that the time averaging process is performed using a number of data inversely proportional to the incoherent integration time so that the time for averaging the data is constant regardless of the altitude. .

The data acquisition rate calculator 7 calculates the data acquisition rate from the Doppler velocity data from the Doppler velocity calculator 3 and inputs the data acquisition rate to the integration time setting section 5. Integration time setting section 5
Sets the incoherent integration time of each altitude range based on the data acquisition rate calculated by the data acquisition rate calculation unit 7. The incoherent integration time at each altitude output from the integration time setting unit 5 is also input to the altitude hourly average number setting unit 8 together with the incoherent integration unit 2. The altitude hourly average number setting unit 8 sets the number of data inversely proportional to the input incoherent integration time as the time average number at each altitude. The quality control / time average processing unit 4 performs time average processing using the time average number. As a result, the Doppler velocity data output from the quality control / time average processing unit 4 is output at the same time interval regardless of the altitude.

In the description of the third embodiment, the data acquisition rate is calculated using the Doppler speed data output from the Doppler speed calculation unit 3. However, the quality control / time average processing unit The data acquisition rate may be calculated by inputting the Doppler velocity after the time averaging output from 4 to the data acquisition rate calculation unit 7. FIG. 11 is a block diagram showing a signal processing device in a wind profiler having such a configuration. In this case, the data input to the data acquisition rate calculation unit 7 is performed only by the quality control / time average processing unit 4 instead of the Doppler speed calculation unit 3,
Others are the same as FIG.

Also, in the third embodiment, a data interpolation processing unit 6 is provided between the Doppler velocity calculation unit 3 and the quality control / time averaging processing unit 4 as in the above embodiments. Interpolation processing may be performed on the Doppler velocity data input from the Doppler velocity calculation unit 3 to output a Doppler velocity having a constant time resolution to the quality control / time averaging processing unit 4 regardless of the altitude.

As described above, according to the third embodiment, the time average number of each altitude is instructed from the altitude hourly average number setting unit 8 to the quality management / time average processing unit 4.
Since Doppler speed data or wind speed data can be obtained at the same time interval at all altitudes, data is easy to use in secondary use of wind speed data, such as using wind speed data as an initial value for numerical weather forecasting The effect of being able to output in form is obtained.

Embodiment 4 In the third embodiment, the case where the Doppler velocity data is output at the same time interval regardless of the altitude has been described. However, the present invention is not limited thereto. Hereinafter, such a fourth embodiment of the present invention will be described with reference to FIG.

FIG. 12 is an explanatory diagram showing a method of updating the time range of incoherent integration according to the fourth embodiment of the present invention. In FIG. 12, it is assumed that the incoherent integration time is short at a low altitude and the incoherent integration is long at a high altitude. When updating the time range of the incoherent integration at a high altitude, the incoherent integration time ranges are overlapped in the incoherent integration in the preceding and following time zones, and are updated at the same time interval as the low altitude. Thus, even if the incoherent integration time differs depending on the altitude, the time interval of the output Doppler velocity does not depend on the altitude.

As described above, according to the fourth embodiment, the update width of the integration range in the time direction in the incoherent integration is constant regardless of the incoherent integration time. The time resolution of the data obtained after the incoherent integration can be made constant regardless of the altitude.

[0076]

As described above, according to the present invention, the input received signal data is subjected to Fourier transform by the FFT processing unit, and the optimum incoherent integration time is set for each altitude by the integration time setting unit. Then, from the Fourier-transformed data, a power spectrum is calculated in an incoherent integration unit, and the power spectrum is time-integrated for a set incoherent integration time, and a Doppler velocity calculation unit calculates a signal spectrum from the power spectrum. The peak is detected, the gaze velocity of the atmosphere is calculated from the Doppler frequency, and the quality control / time averaging processing unit removes low-quality Doppler velocity data and performs time averaging to measure wind speed. The incoherent integration time is set for each altitude, and the At the appropriate time resolution depending on the nature of the target, it is possible to realize the signal processing with high detection performance, there is an effect that the signal processor is obtained in the wind profiler.

According to the present invention, the incoherent integration time at low altitude is set to be short, and the incoherent integration time at high altitude is set to be long.
At a low altitude near the ground surface, it is possible to measure the wind velocity vector with a high time resolution, and it is possible to maintain a high data acquisition rate even at a high altitude where the SN ratio decreases.

According to the present invention, the data acquisition rate calculator sets the incoherent integration time in accordance with the data acquisition rate calculated from the Doppler velocity data output from the Doppler velocity calculator. Because
By increasing the incoherent integration time at altitudes where the data acquisition rate is low, even if the data acquisition rate changes due to changes in weather conditions, the appropriate incoherent integration time can be set adaptively,
It is possible to always maintain the optimal signal processing performance, and even if the characteristics of
Since the incoherent integration time is automatically set, there are effects such as easy signal processing setting at the time of installation.

According to the present invention, the integration time setting section sets the incoherent integration time according to the data acquisition rate calculated by the data acquisition rate calculation section from the Doppler velocity data output from the quality control / time averaging processing section. With this configuration, the incoherent integration time is increased at altitudes where the data acquisition rate is low, so that even when the data acquisition rate changes due to changes in weather conditions, an appropriate incoherent integration time is set adaptively. It is possible to maintain the optimal signal processing performance at all times, and to automatically set the incoherent integration time even if the characteristics of the airflow differ depending on the observation location. There is an effect that the signal processing setting at the time becomes easy.

According to the present invention, the integration time setting unit is configured to set the incoherent integration time at each altitude based on the data acquisition ratio for each altitude calculated by the data acquisition ratio calculation unit. There is an effect that the advanced incoherent integration time can be set more accurately.

According to the present invention, based on the data acquisition rate for each of the previously divided altitude ranges from the data acquisition rate calculation unit, the integration time setting unit calculates the incoherent integration time for each of the previously divided altitude ranges. Since the configuration is such that the setting is made, the processing is simplified as compared with the case where the incoherent integration time is set for each altitude, and there is an effect that the processing load required for determining the incoherent integration time can be reduced.

According to the present invention, at altitudes where the incoherent integration time is set to be long, data is interpolated in the time direction by the data interpolation processing unit, and the Doppler speed is controlled at a constant time resolution regardless of the altitude. Since it is configured to output to the average processing unit, Doppler velocity data or wind velocity data can be obtained at the same time interval at all altitudes, and when wind velocity data is used as the initial value of numerical weather forecast, wind velocity data There is an effect that it becomes possible to output data in a form that is easy to use when secondary use is performed.

According to the present invention, the time averaging processing by the quality control / time averaging processing unit is performed using the number of data inversely proportional to the incoherent integration time, and the Doppler velocity at which the time resolution of the data becomes constant regardless of the altitude. , So that Doppler speed data or wind speed data can be obtained at the same time interval at all altitudes, and secondary use of wind speed data, such as when wind speed data is used as an initial value for numerical weather forecasting. In this case, there is an effect that data can be output in a format that is easy to use.

According to the present invention, the update width of the integration range in the time direction in the incoherent integration is made constant regardless of the incoherent integration time, and the time resolution of the integrated data output from the incoherent integration unit is set to a high level. , So that Doppler speed data or wind speed data can be obtained at the same time interval at all altitudes.If wind speed data is used as the initial value of numerical weather forecast, wind speed data Can be output in a form that is easy to use secondarily.

According to the present invention, a data reading step of reading data of a received signal, an FFT step of performing a Fourier transform on the data of the received signal, an integration time setting step of setting an incoherent integration time for each altitude, A power spectrum is calculated from the Fourier transform of the data of the received signal, an incoherent integration step of performing incoherent integration for a set incoherent integration time, and a signal spectrum is detected from the power spectrum after the incoherent integration, and the Doppler spectrum is detected. A Doppler velocity calculating step of calculating the Doppler velocity from the frequency, a step of determining an end of the total altitude processing for determining whether or not data of all altitudes has been processed for the data at the time to be processed; The altitude to be processed to the next altitude And an altitude update step that returns to the integration time setting step, and a time that is to be processed when the processing is completed is advanced to the next time, and an altitude that is to be processed is initialized and the time is updated to return to the data reading step. Since the incoherent integration time is set for each altitude by the signal processing method including the steps, signal processing with appropriate time resolution and high detection performance can be realized according to the properties of the target at each altitude. There is an effect that a signal processing method in a wind profiler can be obtained.

According to the present invention, a data reading step of reading data of a received signal, an FFT step of performing a Fourier transform on the data of the received signal, and an integration time initial value setting step of setting an initial value of an incoherent integration time And, a power spectrum is calculated from the Fourier transform of the data of the received signal, an incoherent integration step of performing incoherent integration for a set incoherent integration time, and a signal spectrum is detected from the power spectrum after the incoherent integration, A Doppler velocity calculating step of calculating a Doppler velocity from the Doppler frequency, a data acquisition rate calculating step of calculating a data acquisition rate of an altitude currently being processed from the calculated Doppler velocity, and a calculated data acquisition rate Is compared to a predetermined threshold A data acquisition rate determining step, when the data acquisition rate is less than a threshold value, an integration time determining step of comparing the current incoherent integration time with a predetermined incoherent integration time, and a current incoherent integration time. If the incoherent integration time is less than the predetermined incoherent integration time, the setting of the incoherent integration time is increased and the integration time is increased back to the incoherent integration step. When the incoherent integration time is equal to or longer than a predetermined incoherent integration time, for the data at the time being processed, an all-altitude processing end determination step of determining whether or not data of all altitudes has been processed; If processing is not completed, the altitude to be processed is set to the next altitude And an altitude update step to return to the integration time initial value setting step, and, when the processing is completed, advance the time to be processed to the next time, initialize the altitude to be processed, and read data. Since the incoherent integration time is set for each altitude by the signal processing method consisting of a time update step returning to the step, even if the data acquisition rate changes due to a change in weather conditions, an appropriate incoherent integration Since the time can be set adaptively, the signal processing performance can always be kept at the optimum state, and the incoherent integration time is automatically set even if the characteristics of the wind over the sky vary depending on the observation site. Since the setting is performed, there is an effect that a signal processing method in a wind profiler that facilitates signal processing setting at the time of installation can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a signal processing device in a wind profiler according to Embodiment 1 of the present invention.

FIG. 2 is an explanatory diagram showing the principle of wind speed vector calculation in the first embodiment.

FIG. 3 is an explanatory diagram showing a principle of detecting an atmospheric turbulence echo in the first embodiment.

FIG. 4 is an explanatory diagram showing that speed data output from the signal processing device according to the first embodiment has different time resolutions depending on altitude.

FIG. 5 is a flowchart illustrating a signal processing method in the wind profiler according to the first embodiment.

FIG. 6 is a block diagram showing another configuration example of the signal processing device according to the first embodiment.

FIG. 7 is a block diagram showing a signal processing device in a wind profiler according to a second embodiment of the present invention.

FIG. 8 is a flowchart illustrating a signal processing method in the wind profiler according to the second embodiment.

FIG. 9 is a block diagram showing another configuration example of the signal processing device according to the second embodiment.

FIG. 10 is a block diagram showing a signal processing device in a wind profiler according to Embodiment 3 of the present invention.

FIG. 11 is a block diagram illustrating another configuration example of the signal processing device according to the third embodiment.

FIG. 12 is an explanatory diagram showing a method of updating a time range of incoherent integration according to Embodiment 4 of the present invention.

FIG. 13 is a block diagram showing a general wind profiler to which the present invention and a conventional signal processing apparatus and signal processing method are applied.

FIG. 14 is a block diagram showing a signal processing device in a conventional wind profiler.

[Explanation of symbols]

1 FFT processing unit, 2 incoherent integration unit, 3
Doppler speed calculator, 4 quality control / time averaging processor,
5 integration time setting section, 6 data interpolation processing section, 7 data acquisition rate calculation section, 8 altitude hourly average number setting section, 101
Antenna, 102 transmitting / receiving device, 103 signal processing device, 104 wind speed vector calculating device, 105 display / recording device.

Claims (11)

[Claims] 1. A signal processing device in a wind profiler that radiates an electromagnetic wave into space, receives the electromagnetic wave reflected from the atmosphere, and measures a wind speed from a Doppler frequency of the electromagnetic wave. A Fourier transform processing unit that performs a Fourier transform, and calculates a power spectrum from the data of the received signal that has been Fourier transformed by the Fourier transform processing unit, and converts the power spectrum obtained at a plurality of times by the input incoherent integration time. An incoherent integration unit for performing time integration, an integration time setting unit for setting an optimum incoherent integration time for time-integrating the power spectrum in accordance with altitude, and inputting the same to the incoherent integration unit; From the power spectrum output by the coherent integrator A Doppler velocity calculating unit that detects the peak of the signal spectrum and calculates the line-of-sight velocity of the atmosphere from its center Doppler frequency, and removes low-quality data among the Doppler velocities output from the Doppler velocity calculating unit and saves time. A signal processing apparatus in a wind profiler, comprising: a quality control / time averaging processing unit for performing averaging. 2. The window according to claim 1, wherein the integration time setting section sets a short incoherent integration time at a low altitude and sets a long incoherent integration time at a high altitude. Signal processing device in profiler. 3. A data acquisition rate calculation section for inputting Doppler velocity data output from the Doppler velocity calculation section and calculating a data acquisition rate, wherein the integration time setting section calculates the data acquisition rate by the data acquisition rate calculation section. 2. The signal processing apparatus according to claim 1, wherein an incoherent integration time is set according to the obtained data acquisition rate. 4. A data acquisition rate calculation section for inputting Doppler velocity data output from a quality control / time averaging processing section and calculating a data acquisition rate, wherein the integration time setting section calculates the data acquisition rate. 2. The signal processing apparatus according to claim 1, wherein the incoherent integration time is set according to the data acquisition rate calculated by the section. 5. A data acquisition rate calculation unit for calculating a data acquisition rate for each altitude, and an integration time setting unit based on the data acquisition rate calculated by the data acquisition rate calculation unit. 5. The signal processing device in a wind profiler according to claim 3, wherein said high-level incoherent integration time is set. 6. A data acquisition rate calculating section for calculating a data acquisition rate for each of altitude ranges divided in advance, and an integration time setting section calculates a data acquisition rate calculated by the data acquisition rate calculating section. 5. The signal processing device in a wind profiler according to claim 3, wherein an incoherent integration time is set for each divided altitude range. 7. Inputting data output from a Doppler velocity calculation unit and interpolating the data in the time direction at an altitude where a long incoherent integration time is set,
A data interpolation processing unit that outputs a Doppler velocity with a constant time resolution regardless of altitude, and a quality control / time averaging processing unit that inputs the Doppler velocity output from the data interpolation processing unit. The signal processing device in a wind profiler according to any one of claims 1, 3, and 4. 8. An altitude hourly average number setting in which an incoherent integration time at each altitude output from an integration time setting section is input, and the number of data inversely proportional to the incoherent integration time is set as a time average number at each altitude. A quality control / time average processing unit that performs a time average process using the time average number of each altitude output from the altitude hourly average number setting unit. Claim 3,
Alternatively, a signal processing device in the wind profiler according to claim 4. 9. The method according to claim 1, wherein the incoherent integration unit makes the update width of the integration range in the time direction constant when performing the incoherent integration regardless of the incoherent integration time. A signal processing device in a wind profiler according to claim 4. 10. A signal processing method in a wind profiler for radiating an electromagnetic wave into a space, receiving the electromagnetic wave reflected from the atmosphere, and measuring a wind speed from the Doppler frequency, a data reading step of inputting data of a received signal. A Fourier transform step of performing a Fourier transform on the data of the received signal input in the data reading step; an integration time setting step of setting an incoherent integration time for each altitude; and a Fourier transform in the Fourier transform step A power spectrum is calculated from the data of the received signal, and an incoherent integration step of performing incoherent integration for the incoherent integration time set in the integration time setting step, and after incoherent integration by the incoherent integration step power A Doppler velocity calculation step of detecting a signal spectrum from the spectrum and calculating a Doppler velocity from the Doppler frequency, and an all-altitude processing for determining whether or not data of all altitudes has been processed for the data at the time of processing. An end determination step, and when it is determined that the processing of all altitude data has not been completed in the all-altitude processing end determination step, the altitude to be processed is updated to the next altitude, and the integration time setting step is performed. And an altitude update step of returning the processing to the above, and when it is determined that the processing of all the altitude data has been completed in the all-altitude processing end determining step, the time to be processed is advanced to the next time, and the processing is performed. A time update step for initializing the altitude and returning the processing to the data reading step; Kicking signal processing method. 11. A signal processing method in a wind profiler for radiating an electromagnetic wave into a space, receiving the electromagnetic wave reflected from the atmosphere, and measuring a wind speed from the Doppler frequency, a data reading step of inputting data of a received signal. A Fourier transform step of performing a Fourier transform on the data of the received signal input in the data reading step; an integration time initial value setting step of setting an initial value of an incoherent integration time; and the Fourier transform step. An incoherent integration step of calculating a power spectrum from the data of the Fourier-transformed received signal and performing incoherent integration for the incoherent integration time set in the integration time setting step; and incoherent by the incoherent integration step After integration Detecting a signal spectrum from a power spectrum and calculating a Doppler velocity from the Doppler frequency, and a Doppler velocity calculated in the Doppler velocity calculating step, the data acquisition rate of the altitude currently being processed is calculated from the Doppler velocity calculated in the Doppler velocity calculating step. A data acquisition rate calculation step to calculate; a data acquisition rate determination step of comparing the data acquisition rate calculated in the data acquisition rate calculation step with a predetermined threshold value; and a data acquisition in the data acquisition rate determination step. When the rate is determined to be less than the threshold, an integration time determining step of comparing the current incoherent integration time with a predetermined incoherent integration time, and the incoherent integration time in the integration time determining step At a predetermined incoherent integration If it is determined that the value is less than the value, the setting of the incoherent integration time is increased, and the integration time is increased by returning the process to the incoherent integration step. Is determined, or when the incoherent integration time is determined to be equal to or greater than the upper limit value in the integration time determination step, whether or not data at all altitudes has been processed for the data at the time to be processed All altitude processing end determination step of determining, and when it is determined that the processing of all altitude data is not completed in the all height processing end determination step, the altitude to be processed is updated to the next altitude. The altitude update step of returning the processing to the integration time setting step; and the processing of all the altitude data is completed in the all altitude processing end determination step. If it is determined, the signal to be processed is advanced to the next time, the altitude to be processed is initialized, and a time update step for returning to the data reading step is performed. Processing method.