JP2002243854A - Dual system meteorological radar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that there appears a deterioration of the observation accuracy of a Doppler velocity due to a deviation, etc., of the output timing of a transmission pulse, based on the asynchronization of a main system master trigger with an operating clock of a sub-system from a sub-system master trigger, and hence a high reliability observation of the Doppler velocity must be compatible with a high accuracy observation thereof. SOLUTION: A main system 15a and a sub-system 15b respectively comprise receivers 10a, 10b for phase-detection of a received pulse signal converted into an intermediate frequency and a transmission leaking signal, received pulse selectors 16a, 16b for selecting the phase-detected signals in accordance with the switching condition of a waveguide switch after the phase detection, discriminators 17a, 17b for discriminating the selected signals, and Doppler velocity calculators 12a, 12b for calibrating the phases of the discriminated received pulse signals using the phase of the transmission leaking signal, and calculating the Doppler velocity of a target from the calibrated received pulse signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual meteorological radar system applied to observation of so-called meteorological phenomena such as cloud, rain and fog.

[0002]

2. Description of the Related Art In recent years, as a means for observing meteorological phenomena such as cloud, rain, and fog, use of a Doppler radar apparatus capable of closely observing a wind field in time and space has been advanced. In general, a Doppler radar device for weather observation (hereinafter referred to as a weather radar device) is a pulse radio wave (hereinafter, referred to as a “wavelet”) composed of a plurality of pulses for a target such as a cloud, rain, or fog to be observed.
A transmission pulse signal) is emitted, and a pulse radio wave (hereinafter, referred to as a reception pulse signal) reflected from a target object is measured for a Doppler phase difference between reception pulses based on the Doppler effect, and based on the Doppler phase difference. To calculate the Doppler velocity of the target. As a method of calculating the Doppler velocity of the target, a method is used in which the reflected received pulse signal is sampled for each pulse, and the time series is subjected to FFT transform to obtain a frequency distribution, and based on a phase change between two pulses. There is a signal processing method such as a pulse pair method for obtaining an average phase difference between received pulse signals.

The radar apparatus described in Japanese Patent Application Laid-Open No. 3-54495 corrects a phase variation between transmission pulses (between transmission pulses), which is a cause of a Doppler velocity measurement error based on the frequency instability of a magnetron. In order to prevent the observation accuracy from deteriorating, a phase lock-in signal is generated for each transmission pulse from the transmission pulse signal output from the magnetron, and the phase detection processing of the reception pulse signal is performed based on the phase lock-in signal. There is also a type in which a phase detection process of a reception pulse signal is similarly performed using a digital signal after A / D conversion of a transmission pulse signal output from a magnetron.

Since this type of weather radar device is used as a sensor of a disaster prevention system related to human life such as a lightning observation system and a rain gauge system, it is necessary to avoid a drop in reliability due to a component failure or the like. The system configuration of the system is often used. Also, in this case, the above-described phase-locked-in signal and transmission pulse signal are input between the two sets of the receiving unit and the signal processing unit, respectively, and the signal processing unit performs the phase detection processing.

FIG. 6 is a block diagram showing a conventional general dual weather radar apparatus. In the figure, 15a and 15b are a main system unit and a sub system unit that constitute this dual system weather radar device, and both have the same configuration. Reference numerals 1a and 1b denote synchronization pulse output units for respectively outputting a plurality of pre-trigger pulses and a synchronization pulse signal (hereinafter, referred to as a master trigger). Here, the pre-trigger pulse controls a transmission pulse cycle of the apparatus, that is, an output timing of each transmission pulse signal, which is set according to an observation target (hereinafter, referred to as a target) such as cloud, rain, and fog, and observation conditions. This is a signal for causing the transmission sections 2a and 2b to output a transmission pulse signal. The master trigger is a synchronization pulse signal composed of a plurality of master trigger pulses which are a time reference of the transmission pulse period of the transmission pulse signal, that is, the transmission repetition frequency.

[0006] The transmission units 2a and 2b include a pulse signal generation unit 3
a, 3b and transmitting elements 4a, 4b. The pulse signal generators 3a and 3b generate a pulse signal as a modulation signal based on each pre-trigger from the synchronization pulse output units 1a and 1b. The transmission elements 4a and 4b are formed of self-oscillation type transmission tubes such as magnetrons, and transmit high-frequency transmission pulses pulse-modulated by pulse-like modulation signals output from the pulse signal generation units 3a and 3b. These are output in units.

[0007] Reference numerals 5a and 5b denote circulators which output transmission pulse signals output from the transmission elements 4a and 4b to the transmission / reception antenna unit 6, and receive a reception pulse signal received via the transmission / reception antenna unit 6 in a reception unit 10a described later. , 10b
Output to The transmission / reception antenna unit 6 is configured to be rotatable in elevation and azimuth directions.
A transmission pulse signal composed of a plurality of pulses inputted from a and 4b is radiated to a target or the like with a predetermined beam width, and a reception pulse signal composed of a plurality of pulses reflected back from the target or the like is received. Things.

Reference numeral 7 denotes a waveguide switching section (system switching means) which includes a circulator 5a and a slave section 15b on the main system section 15a side.
The circulator 5b on the side is switched. 8a,
8b is a STALO that outputs a local oscillation signal of a predetermined frequency.
(Local oscillator), 9a and 9b are STALO8a,
This is a mixer that converts a received pulse signal into an IF signal of an intermediate frequency based on the local oscillation signal output from 8b. 10
Reference numerals "a" and "10b" denote receiving sections for performing phase detection processing on the reception pulse signal converted into the intermediate frequency by the mixers 9a and 9b and outputting a reception video signal.

Reference numerals 11a and 11b denote Doppler speed processing units, which are composed of Doppler speed calculation units 12a and 12b and data processing units 13a and 13b. The Doppler speed processing units 11a and 11b perform various processes such as calculating the Doppler speed of the target from the received pulse signal and displaying the target on the display unit 14 based on the calculated Doppler speed and the like. is there. Doppler velocity calculator 12
“a” and “12b” are for calculating the Doppler velocity of the target from the phase difference between the received pulses of the received video signals output from the receiving units 10a and 10b. Data processing unit 13
a and 13b display the size, shape, type, and the like of the target on the display unit 14 such as a monitor based on the Doppler speed of the target calculated by the Doppler speed calculation units 12a and 12b. Data processing is performed so that an operator can recognize and monitor a target and a Doppler velocity of the target.

Next, the operation will be described. The master trigger is a synchronization signal serving as a reference for time synchronization between the transmission operation and the reception operation, and is a signal that defines a transmission repetition frequency of a transmission pulse signal emitted to an observation target. The master trigger is a signal that is output at a fixed time interval after the output of the pre-trigger pulse and serves as a common time reference for the transmission / reception operation. If the output timing of the transmission pulse output from the transmission units 2a and 2b is sequentially output in synchronization with the output timing of the master trigger pulse, the transmission timing of the transmission pulse signal is synchronized with the output timing of the master trigger. . If the transmission pulse is output at an output timing shifted from the master trigger, the transmission timing of the transmission pulse signal has a pulse synchronization shift with respect to the output timing of the master trigger. Then, even if sampling based on the output timing of the master trigger is performed on the reception pulse signal from the target with respect to the transmission pulse signal having such a pulse synchronization shift, the sampling position of each reception pulse has Due to the deviation of the pulse synchronization, it is shifted back and forth from a predetermined sampling position.

When the main section 15a is selected by the waveguide switching section 7, the transmission pulse output from the transmitting section 2a is generated by the synchronous pulse output section 1a. , The master trigger). The master master trigger input from the synchronization pulse output unit 1a to the synchronization pulse output unit 1b is sampled by the operation clock of the slave unit 15b, and becomes a master trigger of the slave unit 15b (hereinafter referred to as slave master trigger). . The master master trigger and the slave master trigger become asynchronous based on the fact that the operation clock of the master part 15a and the operation clock of the slave part 15b are asynchronous. Therefore,
The transmission pulse signal output from the transmission section 2a is asynchronous with the slave master trigger, and the output timing of the transmission pulse signal and the output timing of the slave master trigger are shifted in time.

Hereinafter, the deterioration of the observation accuracy of the Doppler velocity in the slave unit 15b due to the difference between the output timing of the transmission pulse signal and the output timing of the slave master trigger will be described with reference to FIGS. FIG. 4 is an explanatory diagram showing an output relationship between a transmission pulse output from a magnetron transmission element and a master trigger, and FIG. 5 is a pulse characteristic diagram showing pulse characteristics of each transmission pulse shown in FIG. In addition,
The first and second transmission pulses shown in FIG. 4 show two arbitrary transmission pulses from a transmission pulse signal composed of a plurality of pulses, and show an output relationship with a master trigger.

In the main system unit 15a, the transmission pulse period of the transmission pulse signal radiated from the transmission antenna to the observation target becomes constant in accordance with the transmission repetition frequency. Each transmitted pulse of
The signal is output from the transmission unit 2a of the main unit 15a at an output timing that is temporally shifted back and forth from the output timing of the slave master trigger, which is a synchronization signal. Such a transmission operation can be performed even if the trigger pulse period of the trigger signal input to the transmission section 2a of the main section 15a is set to be constant according to the transmission repetition frequency. This is an operation based on the asynchronous of the department master trigger.

The relationship between the slave master trigger and the output timing of the transmission pulse of the master part 15a is as shown in FIG. 4, for example. In the figure, the first transmission pulse is synchronized with the output timing of the slave master trigger, but the second transmission pulse is output at a timing that is temporally shifted from the output timing of the slave master trigger. The transmission pulse signal is composed of a plurality of pulses. Thus, for example, the transmission pulse signal output from the transmission element 4a of the magnetron has an output timing that is temporally shifted back and forth from the output timing of the slave master trigger. When the slave master trigger is used as a reference, a transmission pulse signal having an irregular transmission pulse period is emitted to the observation target as a whole.

The received pulse signal reflected from the object to be observed is sampled by the Doppler velocity calculators 12a and 12b in accordance with the output timing of the master trigger which is a synchronization signal as described above. The reason why the sampling positions of the reception pulse signals by the speed calculation units 12a and 12b are the same in each reception pulse signal is that the transmission timing of the transmission pulse signal is output in synchronization with the output timing of the master trigger. is there. As described above, for a reception pulse signal corresponding to a transmission pulse signal that is asynchronous with the master trigger, that is, the output timing of the transmission pulse is temporally shifted from that of the slave master trigger, the sampling position of each reception pulse is between each reception pulse. Are shifted from each other by
The sampling position will be different for each received pulse.

The Doppler velocity is measured based on the difference between the Doppler phases of the received pulses measured at the sampling position, that is, the Doppler phase difference between the received pulses. Therefore, when the sampling position of the received pulse is shifted due to the shift of the transmission timing as described above, the Doppler velocity of the observation object is determined from the phase difference between the Doppler phases measured at the mutually shifted sampling positions. Will be observed. For example, in a reception pulse (not shown) corresponding to the first and second transmission pulses in FIG. 4, the first reception pulse is at a pulse rising position, and the second reception pulse is at a pulse falling position. The Doppler phase will be measured for each. However, it is assumed that sampling is performed at the rising timing of the master trigger.

Next, the pulse characteristics of the transmission pulse signals output from the transmission elements 4a and 4b of the magnetron shown in FIG. 5 will be described, and when there is a difference between the transmission pulse and the output timing of the slave master trigger, The degradation of the Doppler velocity observation accuracy based on the pulse characteristics of the transmission pulse signal will be described. In FIG. 5, the upper part is an amplitude characteristic diagram, the lower part is a phase characteristic diagram, and the horizontal axis is a common time axis in the upper and lower characteristic diagrams. The transmission element 4a of the magnetron,
The pulse characteristic of the transmission pulse signal output from 4b has, for example, a time-amplitude characteristic and a time-phase characteristic as shown in FIG. 5 due to the instability of the frequency characteristic.
As shown in the phase characteristic diagram, the phase in the transmission pulse output from the transmission elements 4a and 4b changes in a complex form in which the phase change rate is not constant from the pulse rising to the pulse falling.

Therefore, even if the Doppler velocity of the stationary target is measured from the received pulse signal reflected from the stationary target, the sampling positions of the received pulses are shifted from each other as shown in FIG. Each received pulse has its Doppler phase measured at the mutually different sampling position. The Doppler velocity of the stationary target is measured from the Doppler phase difference of the received pulse measured at the mutually shifted sampling positions. For example, assuming that the reception pulse corresponding to the transmission pulse shown in FIG. 4 is reflected back from the stationary target, the phase measurement position of the first reception pulse is a pulse rising portion (arrow A in FIG. 5). In the case where the phase measurement positions of the two received pulses are sampled at the pulse rising portion (arrow B in FIG. 5), the observation target whose Doppler velocity is actually zero is as shown in the phase characteristic diagram in the lower part of FIG. Is determined to have a Doppler phase difference Ti, and the observation object is observed to be moving at a Doppler velocity corresponding to the Doppler phase difference Ti.

In general, when calculating the Doppler velocity of an observation target by the pulse pair method or the like, the Doppler velocity of the observation target is calculated from the Doppler phase difference between any two received pulses in the received pulse signal reflected from the observation target. . If the Doppler phases of these received pulses are measured at the same phase measurement position, the Doppler velocity of an observation object that does not move itself, such as a building, will have no Doppler effect and the Doppler phase difference between the received pulses Is measured to be zero and the Doppler velocity is observed to be zero. However, as described above, the transmission pulse signals output from the transmission elements 4a and 4b of the magnetron are output at transmission timings shifted from the output timing of the slave master trigger, and are output at such transmission timings. When the reception pulse signal corresponding to the transmission pulse signal is sampled at the output timing of the slave master trigger, the sampling position of each reception pulse, that is, the phase measurement position is shifted between the reception pulses, and an erroneous Doppler velocity is observed. .

[0020]

Since the conventional dual weather radar system is configured as described above, for example, the receiving unit 10a of the main system unit 15a that generates a master trigger.
And the slave unit 1 on the side that samples the master master trigger with the operation clock of the own system and generates the master trigger of the own system.
If the Doppler speed processing unit 11b of 0b fails at the same time, the system is immediately stopped. In addition, in order to improve the reliability of the system, the reception pulse signal is input between the two reception units 10a and 10b and the Doppler speed processing units 11a and 11b by cross-crossing, so that the main system unit is operated in the same manner as described above. If the receiving unit 10a of 15a and the Doppler speed processing unit 11b of the subordinate unit 15b fail at the same time, it is possible to avoid system stoppage. However, the deterioration of the Doppler velocity observation accuracy due to the difference between the output timing of the transmission pulse and the slave master trigger of the slave part 15b, etc., based on the asynchronous operation of the master master trigger and the operation clock of the slave part 15b as described above. Inevitably, it has been a challenge to achieve both high reliability and high-precision Doppler velocity observation as a dual system radar system.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and it is possible to prevent deterioration of Doppler velocity observation accuracy due to a shift between a transmission timing of a transmission pulse and a slave master trigger, thereby achieving high reliability. It is an object of the present invention to obtain a dual-system meteorological radar device that can simultaneously observe the Doppler velocity with high accuracy.

[0022]

SUMMARY OF THE INVENTION A dual weather radar system according to the present invention transmits a main pulse and a sub-channel having the same configuration for performing each signal processing for transmission and reception, and transmits a transmission pulse signal to a target. A transmitting and receiving antenna unit for receiving a received pulse signal reflected by the target, a system switching unit for switching and connecting the main system unit and the subordinate unit to a transmitting and receiving antenna, and a Doppler speed of the target and the like. The size of the target,
In a dual weather radar device comprising a display unit for displaying both the shape, type, etc., each of the main system unit and the slave system unit receives the reception pulse signal and the transmission leakage signal of the transmission pulse signal. A mixer for converting the received pulse signal and the transmission leakage signal converted to the intermediate frequency, a reception unit for performing phase detection of the reception pulse signal and the transmission leakage signal, and the reception pulse signal and the transmission leakage signal after the phase detection, A reception pulse selection unit that selects according to the switching state of the switching unit, a discrimination unit that discriminates the reception pulse signal after the phase detection selected by the reception pulse signal selection unit from a leak signal, and a reception pulse that is discriminated. The phase of the signal is calibrated for the measurement error of the Doppler velocity caused by the asynchronization of the output timing of the transmission pulse signal and the slave master trigger using the phase of the transmission leakage signal. From calibrated received pulse signal is obtained by a Doppler velocity calculation unit for calculating a Doppler velocity of the target.

The dual weather radar device according to the present invention comprises:
A main unit and a slave unit having the same configuration for performing each signal processing for transmission and reception, a transmission and reception antenna unit for transmitting a transmission pulse signal to a target and receiving a reception pulse signal reflected by the target, A system switching means for switching and connecting a system unit and the slave system unit to a transmission / reception antenna, and a display system for displaying the size, shape, type, etc. of the target from the Doppler speed of the target, etc. In the weather radar device, each of the main system unit and the slave system unit performs phase detection on a reception pulse signal and a transmission pulse signal converted into an intermediate frequency, and a reception pulse signal and a transmission pulse signal after phase detection. A receiving pulse selecting unit for selecting a signal according to the switching state of the system switching unit, and discriminating the receiving pulse signal and the transmitting pulse signal after the phase detection selected by the receiving pulse signal selecting unit. That a discriminator, to calibrate the output timing and measurement error of the Doppler velocity caused by asynchronous slave master trigger when phase discrimination reception pulse signal using the phase of the transmission pulse signal the transmission pulse signal,
A Doppler velocity calculator for calculating the Doppler velocity of the target from the calibrated received pulse signal.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. 1 to 3 are diagrams for explaining the first embodiment. FIG. 1 is a block diagram showing a dual weather radar system according to Embodiment 1 of the present invention. In the figure, portions corresponding to those in FIG. The different parts will be described. The parts newly provided in FIG. 6 include reception pulse selection units 16a and 16b and discrimination unit 17 in Doppler velocity processing units 11a and 11b.
a and 17b are provided.

The difference in operation is that, in the circulators 5a and 5b, a part of the transmission power of the transmission pulse leaks into the reception unit due to the degree of coupling between the reception port and the transmission port, and the transmission leakage signal is generated. appear. Receiver 10
The a and 10b are configured to perform a phase detection process on the transmission leakage signal converted into the intermediate frequency by the mixers 9a and 9b or the reception pulse signal converted into the intermediate frequency to output a reception video signal. Receive pulse selectors 16a, 16
“b” uniquely selects a reception pulse signal from the reception pulse signals output from the reception units 10a and 10b in a cross-linked manner in accordance with system switching of the dual weather radar. Discriminator 17
a and 17b operate to discriminate the transmission leakage signal from the reception pulse signals selected by the reception pulse selection units 16a and 16b. Doppler velocity calculators 12a, 12b
Calibrates the phase of the reception pulse discriminated by the discrimination units 17a and 17b with the phase of the transmission leakage signal, and calculates the Doppler velocity of the target from the phase difference of each reception pulse of the calibrated reception pulse signal.

FIG. 2 is a schematic explanatory diagram of a weather observation situation by the dual weather radar device according to the first embodiment of the present invention. A transmission pulse radio wave, that is, a transmission pulse signal composed of a plurality of pulses output from the transmission units 2a and 2b is radiated from the reception antenna unit 6 to a cloud as an observation target object with a predetermined beam width as shown in the drawing. The reflected wave composed of a plurality of pulses reflected from the cloud, that is, a received pulse signal, is received by the transmitting / receiving antenna unit 6, and the Doppler velocity is calculated from the received pulse signal. For example, if the cloud moves in the direction away from the transmitting / receiving antenna section 6, the Doppler effect in the direction away from the received pulse (for example, in the positive direction) occurs, and the Doppler phase difference in the positive direction is measured. In addition, if it is stationary, the Doppler phase difference due to the Doppler effect is measured as zero. Based on the measurement of the Doppler phase difference, the movement of the cloud and the like are observed.

The Doppler velocity of the target is calculated based on the Doppler phase difference between the received pulses of the received received pulse signal. If at least two received pulses exist in the received pulse signal, The Doppler velocity of the target can be calculated in principle from the received pulses. However, in the dual meteorological radar device according to Embodiment 1, the properties of the target and the
In consideration of the frequency characteristics of the magnetrons used as a and 4b, a large number of transmission pulse signals are emitted to the target as shown in FIG. 2, and the respective Doppler velocities respectively calculated from the plurality of reception pulse signals. Is measured as the Doppler velocity of the target. The number of transmission pulse signals emitted to the target is determined by the S / N of the reception signal.
Ratio, velocity range of the target (clouds, rain, fog, etc.
It is composed of raindrops and the like, and its internal state is irregular and changes complicatedly, and the Doppler velocity differs depending on the measurement location. ) Was taken into account and the optimal number was set, so that the Doppler velocity of the target could be more accurately observed.

FIG. 3A shows the transmission pulse signals T1 and T2 of the dual weather radar system according to the first embodiment and the reception pulse signals R1 and R1 reflected from the target in response to the transmission pulse signals. FIG. 3B is an explanatory diagram showing transmission / reception timing with R2, FIG. 3B is an explanatory diagram showing a video signal obtained by performing a phase detection process on a received pulse signal received via the transmission / reception antenna unit 7, and FIG. FIG. 4 is an explanatory diagram showing a relationship between a video signal (I-channel signal and Q-channel signal) shown in (b) and a Doppler phase. FIG. 3 (b)
As shown in FIG. 3 (c), the videoized reception pulse signal is composed of I channel and Q channel signals. In general, the target Doppler velocity V
For example, d is calculated from the phase difference based on the Doppler effect generated between the reception pulses of the reception pulse signal reflected back from the target, and is calculated by the following equation.

Vd = fd · λ / 2 (1)

Here, fd is the Doppler frequency, and λ is the wavelength of the transmission radio wave (hereinafter referred to as transmission wavelength). The Doppler frequency fd can be obtained by the following equation, in accordance with the description of FIGS. 3B and 3C. The transmission wavelength λ differs depending on the frequency band used in the weather radar device, such as the millimeter wave band and the centimeter wave band.

Fd = (Φi + 1−Φi) / 2 · π · Δt (2)

Here, Φi is the Doppler phase of the first received pulse R1 after the phase calibration, Φi + 1 is the Doppler phase of the second received pulse R2 after the phase calibration, and Δt is the difference between the received pulse R1 and the received pulse R2. Is the pulse interval provided in The video signals corresponding to the first reception pulse R1 are Ii and Qi, and the second reception pulse R
Assuming that the video signals for 2 are Ii + 1 and Qi + 1,
The Doppler phase θi before the phase calibration of the first reception pulse R1 and the Doppler phase θi + 1 before the phase calibration of the second reception pulse R2 are calculated from the relationship between the I channel signal and the Q channel signal shown in FIG. It can be obtained by equations (3) and (4), respectively.

Θi = tan ⁻¹ (Qi / Ii) (3)

Θi + 1 = tan ⁻¹ (Qi + 1 / Ii + 1) (4)

If the video signal for the first transmission leakage signal or transmission pulse T1 is Iti, Qti, and the video signal for the second transmission leakage signal or transmission pulse T2 is Iti + 1, Qti + 1, the Doppler of the reception pulse R1 after the phase calibration is obtained. The phase Φi and the Doppler phase Φi + 1 of the received pulse R2 can be obtained by the following equations (5) and (6), respectively.

Φi = tan ⁻¹ (Qi / Ii) −tan ⁻¹ (Qti / Iti) (5)

Φi + 1 = tan ⁻¹ (Qi + 1 / Ii + 1) −tan ⁻¹ (Qti + 1 / Iti + 1) (6)

Thus, the Doppler velocity Vd of the target object
In order to obtain the Doppler phase, first, the Doppler phase is obtained from the received pulse signal reflected back from the target, and then the Doppler phase is calibrated based on the Doppler phase obtained from the transmission leakage signal or the transmission pulse signal. . Further, the phase difference between the received pulses is obtained. That is, in the first embodiment, the phase difference between the reception pulse R1 and the reception pulse R2 is obtained from each Doppler phase shown in Expressions (5) and (6). Next, based on this phase difference, the Doppler frequency fd of the target is obtained from equation (2). Finally, based on this Doppler frequency fd, the Doppler velocity Vd is obtained from equation (1).

As described above, according to the first embodiment, the discrimination units 17a and 17b transmit the reception pulse and the transmission pulse signal selected by the reception pulse signal selection units 16a and 16b to the reception units 10a and 10b. The leakage signal is discriminated, the phase of the reception pulse signal discriminated by the Doppler velocity calculation units 12a and 12b is calibrated with the phase of the transmission leakage signal, and the Doppler velocity of the target is calculated from the calibrated reception pulse. Therefore, there is no occurrence of a measurement error of the Doppler velocity caused by the asynchronism between the output timing of the transmission pulse signal and the slave master trigger, and the effect of achieving both high reliability and accurate Doppler velocity observation can be obtained.

Embodiment 2 In the first embodiment, a process has been described in which the phase of the received pulse signal is calibrated with the Doppler phase obtained from the transmission leakage signal, and Doppler observation with high accuracy is performed. On the other hand, there is also a method of calibrating based on the Doppler phase obtained from the transmission pulse signal. Embodiment 2 will be described with reference to FIG. Receiving units 10a, 1
In the case of 0b, the transmission pulse signal is fetched together with the reception pulse signal to perform phase detection. Both the detected reception pulse signal and this transmission pulse signal are input to the reception pulse selection units 16a and 16b. The reception pulse signal and the transmission pulse signal input to the reception pulse selection units 16a and 16b are selected in accordance with system switching of the dual weather radar device by the waveguide switching unit (system switching unit) 7, and are discriminated by the discrimination unit 17a. , 17b to the Doppler velocity calculators 12a, 12b. The Doppler phases of the received pulse signals input to the Doppler velocity calculators 12a and 12b are calibrated using the Doppler phases of the transmitted pulse signals.

According to the second embodiment, the Doppler velocity calculating sections 12a and 12b use the received pulse signal selecting section 16
a, the phase of the reception pulse selected in 16b is calibrated with the Doppler phase of the transmission pulse signal, and the Doppler velocity of the target is calculated from the calibrated reception pulse signal. The measurement error of the Doppler velocity caused by the synchronization of the system master trigger does not occur, and the effect of achieving both high reliability and accurate Doppler velocity observation can be obtained.

[0042]

According to the present invention, each of the main system unit and the sub system unit converts a received reception pulse signal and a transmission leakage signal of a transmission pulse signal into an intermediate frequency,
A receiving unit that performs phase detection on the reception pulse signal and the transmission leakage signal converted to the intermediate frequency, and a reception pulse that selects the reception pulse signal and the transmission leakage signal after the phase detection in accordance with the switching state of the system switching unit A selecting unit, a discriminating unit that discriminates the received pulse signal after the phase detection selected by the received pulse signal selecting unit from the leak signal, and transmits the phase of the discriminated received pulse signal using the phase of the leak signal. A Doppler velocity calculator configured to calibrate a measurement error of the Doppler velocity caused by the asynchronous timing of the output timing of the pulse signal and the slave master trigger, and to calculate the Doppler velocity of the target from the calibrated received pulse signal. Therefore, there is no Doppler velocity measurement error caused by the asynchronous between the output timing of the transmission pulse signal and the slave master trigger. An effect of both observations of dependability and accurate Doppler velocity.

According to the present invention, each of the main system unit and the sub system unit performs phase detection on the reception pulse signal and the transmission pulse signal converted into the intermediate frequency, and receives and transmits the reception pulse signal after the phase detection. A reception pulse selection unit that selects a pulse signal in accordance with a switching state of the system switching unit, a discrimination unit that discriminates a reception pulse signal and a transmission pulse signal after phase detection selected by the reception pulse signal selection unit, Using the phase of the transmission pulse signal, the phase of the reception pulse signal is used to calibrate the measurement error of the Doppler velocity caused by the synchronization of the output timing of the transmission pulse signal and the asynchronous master trigger, and the Doppler of the target is calibrated from the calibrated reception pulse signal. It is configured to have a Doppler speed calculation unit that calculates the speed, so that the output timing of the transmission pulse signal is asynchronous with the slave master trigger. Doppler velocity measurement error does not occur resulting Ri, the effect of both observations of high reliability and high precision Doppler speed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a dual weather radar device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of a weather observation situation according to the first embodiment of the present invention;

FIG. 3 is an explanatory diagram for explaining a Doppler velocity observation method and a calculation method according to the first embodiment of the present invention;

FIG. 4 is an explanatory diagram showing output timings of a transmission pulse of a transmission pulse signal output from a magnetron transmitter and a master trigger.

FIG. 5 is an explanatory diagram showing characteristics of a transmission pulse.

FIG. 6 is a block diagram showing a conventional dual weather radar device.

[Explanation of symbols]

1a, 1b synchronization pulse output unit, 2a, 2b transmission unit,
4a, 4b transmitting element, 5a, 5b circulator,
6 transmission / reception antenna section, 7 waveguide switching section (system switching means), 8a, 8b local oscillator (STALO), 9a,
9b mixer, 10a, 10b receiver, 11a, 11
b Doppler speed processing unit, 12a, 12b Doppler speed calculation unit, 13a, 13b Data processing unit, 14
Display unit, 15a Main system unit, 15b Slave system unit, 16a, 1
6b Received pulse selector, 17a, 17b Discriminator.

Claims (2)

[Claims] 1. A main part and a sub part having the same configuration for performing each signal processing for transmission and reception, and a transmission and reception antenna for transmitting a transmission pulse signal to a target and receiving a reception pulse signal reflected by the target. Unit, system switching means for switching and connecting the main system unit and the slave system unit to a transmitting / receiving antenna, and a display unit for displaying both the size, shape, type, and the like of the target from the Doppler speed and the like of the target. A dual weather radar device comprising: a main unit and a sub system, each of which includes a mixer that converts the received reception pulse signal and the transmission leakage signal of the transmission pulse signal into an intermediate frequency. A receiving unit that performs phase detection on the reception pulse signal and the transmission leakage signal converted to the intermediate frequency, and adjusts the reception pulse signal and the transmission leakage signal after the phase detection according to the switching state of the system switching unit. A reception pulse selection unit to be selected; a discrimination unit that discriminates the reception pulse signal after the phase detection selected by the reception pulse signal selection unit from a leakage signal; and the transmission leakage of the phase of the discrimination reception pulse signal. A Doppler velocity calculation for calibrating a Doppler velocity measurement error caused by the synchronization of the output timing of the transmission pulse signal and the slave master trigger using the signal phase, and calculating the Doppler velocity of the target from the calibrated reception pulse signal. And a dual-system weather radar device. 2. A main part and a sub part having the same configuration for performing each signal processing for transmission and reception, and a transmission and reception antenna for transmitting a transmission pulse signal to a target and receiving a reception pulse signal reflected by the target. Unit, system switching means for switching and connecting the main system unit and the slave system unit to a transmitting / receiving antenna, and a display unit for displaying both the size, shape, type, and the like of the target from the Doppler speed and the like of the target. A dual-system weather radar apparatus comprising: a receiving unit that performs phase detection on a reception pulse signal and a transmission pulse signal that have been converted into an intermediate frequency; and a reception pulse after phase detection. A reception pulse selection unit that selects a signal and a transmission pulse signal in accordance with a switching state of the system switching unit; and a reception pulse signal after the phase detection selected by the reception pulse signal selection unit and transmission. A discriminator for discriminating the pulse signal, and using the phase of the discriminated reception pulse signal as the phase of the transmission pulse signal to calibrate the measurement error of the Doppler velocity caused by the asynchronous timing of the output timing of the transmission pulse signal and the slave master trigger. And a Doppler velocity calculator for calculating a Doppler velocity of the target from the calibrated received pulse signal.