CN101017203A - Portable X wave range Doppler weather radar signal processing method and device thereof - Google Patents

Abstract

This invention relates to one portable X wave section Doppler gas radar signal process method, wherein, the receive sub system processes wide band receive method on signals to form main path amplifier of low noise sound effect tube to form receive system together with reference signal amplifier ad lock phase vibration and stable lock ; adopting wide band for receive within range of 45MHz-75MHz automatically catching and tracing aim signals; Main path amplifier is composed of low noise sound effect, mixture device for selecting echo signal to output middle frequency signal; the reference signal amplifier is composed of mixture device and middle frequency amplifier.

Description

Portable X wave range Doppler weather radar signal processing method and device

Technical field

The invention belongs to the aerological sounding electronic equipment, especially portable x wave range Doppler weather radar signal processing method and device.

Background technology

1) in the present magnetron intermediate frequency system, the Doppler radar great majority adopt the simulation reception techniques, as linear amplifier, and logarithmic amplifier, Simulation with I/Q demodulation, automatic frequency tracking (AFC) etc.Its shortcoming have following some:

Linear dynamic range is low, does not satisfy the detection performance requirement of radar;

The width of cloth of i/q signal balances each other and is difficult to guarantee, influences doppler velocity and spectrum width;

The linear amplifier temperature influence is bigger, is difficult to satisfy the detection accuracy requirement;

The automatic frequency tracking mode be difficult to adjust, and frequency stability is poor.

2) traditionally, digital signal processor adopts low-frequency sampling (I/Q), carries out signal Processing by the signal processor chip (DSP) of special use, obtains intensity, speed and the spectrum width of precipitation such as cloud, rain, shortcoming is that independently computer equipment carries out signal Processing, has increased the radar equipment amount.

3) the general weather radar complex structure of reining in of tradition, volume is big, Heavy Weight; Generally use, can't select mountain top or general roof to use flexibly as the observation place in the fixed location.

Summary of the invention

The present invention seeks to: propose a kind of Doppler radar, utilize digital intermediate frequency and first phase compensation technique, improved the performance that tests the speed of radar; Signal Processing is proposed a kind of broadband receiving method, saved automatic frequency tracking, simplified receiving trap; Propose a kind of virtual signal treatment technology, use PC directly to carry out real time signal processing, saved special-purpose dsp processor, make simplified equipment, reliable, working service is convenient; Remote data transmission and Remote function have been realized; Propose a kind of portable construction design, make this radar more motor-driven, flexible, set up easy to use.

Technical solution of the present invention is: the signal processing method of Portable X wave range Doppler weather radar: on the hardware foundation that is made of antenna feeder subsystem, emission subsystem, reception subsystem, digital if receiver, signal data processing terminal subsystem, servo subsystem, monitoring and power subsystem, receive subsystem signal Processing is adopted broadband receiving method, with low noise field effect transistor amplifier constitute the main road amplifier and with reference signal amplifier (branch amplifier) and phase-locked local oscillator, phase-locked local oscillator of high stable and image rejection mixer formation; Adopt the broadband reception technology, in intermediate frequency 45MHz～75MHz scope, catch automatically and the tracking target signal;

The main road amplifier by the low noise sound field put, frequency mixer and preposition in put etc. and to form; Be mainly used to select echoed signal, and it is amplified and frequency transformation, the output echo signal of intermediate frequency;

Branch amplifier is made up of frequency mixer and intermediate frequency amplifier; The transmitter master ripple that coupling is come to aperture carries out frequency transformation and amplitude is amplified, and direct conversion becomes intermediate-freuqncy signal, and output intermediate frequency reference signal is sent into the signal Processing subsystem; The reference clock signal generator comprises phase-locked local oscillator, and phase-locked local oscillator is made up of crystal oscillator, single-point medium phase locked source and phase-locked oscilaltor, power splitter etc.; It and high-frequency pulse signal mixing produce intermediate-freuqncy signal, export the 100MHz reference signal simultaneously.Reference signal is delivered to the reference clock signal generator; The clock reference of output 80MHz is delivered to the signal Processing subsystem as clock reference after the filtering of reference clock signal generator process, frequency conversion, amplification, the filtering; The faint high frequency echoed signal that receives from the antenna feeder subsystem, behind circulator, discharge tube limiter, send into the main road amplifier that receives subsystem, carry out frequency transformation and put row into by the low noise sound field and amplify, deliver in the image-reject mixer then, echoed signal and local oscillation signal carry out mixing in frequency mixer, the 60MHz of output ± 15MHz intermediate-freuqncy signal; Echo signal of intermediate frequency is carried out being sent to digital if receiver after filtering is amplified.

Use the virtual signal treatment technology, use PC directly to carry out real time signal processing, saved special-purpose dsp processor.Digital if receiver adopts at a high speed and high-precision a/d converter carries out echo and transponder pulse (main ripple) if sampling, numeral IQ demodulation utilizes Floating-point DSP to carry out transponder pulse to carry out local real time spectral analysis and processing, extract the transponder pulse sample information and carry out amplitude and phase correction, produce the system sequence signal; Transmit servo-drive system control information and system monitoring status information; The mutually orthogonal data of two-way (IQ data) after relevant the processing transfer to strange land signal Processing terminal by optical cable.

The Portable X wave range Doppler weather radar is made up of antenna feeder subsystem, emission subsystem, reception subsystem, digital if receiver, signal data processing terminal subsystem, servo subsystem, monitoring and power subsystem; Described reception subsystem comprises low noise field effect transistor amplifier (main road amplifier), reference signal amplifier (branch amplifier) composition; The main road amplifier by the low noise sound field put, the phase-locked local oscillator of high stable suppresses frequency mixer mutually with mirror, frequency mixer and preposition in composition such as put.Branch amplifier is made up of frequency mixer and intermediate frequency amplifier; The transmitter master ripple that coupling is come to aperture carries out frequency transformation and amplitude is amplified, and direct conversion becomes intermediate-freuqncy signal, and output intermediate frequency reference signal is sent into the signal Processing subsystem; The faint high frequency echoed signal that receives from the antenna feeder subsystem, behind circulator, discharge tube limiter, send into the main road amplifier that receives subsystem, putting row into by the low noise sound field amplifies, delivers in the image-reject mixer then, echoed signal and local oscillation signal carry out mixing in frequency mixer, 60MHz ± 15MHz the intermediate-freuqncy signal of output carries out echo signal of intermediate frequency to be sent to digital if receiver after filtering is amplified; The reference clock signal generator comprises phase-locked local oscillator, and phase-locked local oscillator is made up of crystal oscillator, single-point medium phase locked source and phase-locked oscilaltor, power splitter etc.It and high-frequency pulse signal mixing produce intermediate-freuqncy signal, export the 100MHz reference signal simultaneously.Reference signal connects the reference clock signal generator.The clock reference of output 80MHz is delivered to the signal Processing subsystem as clock reference after the filtering of reference clock signal generator process, frequency conversion, amplification, the filtering; Digital if receiver adopts the A/D transducer of 14 of high speed, high precision that echo and the transmitted-reference pulse of 60MHz are sampled respectively, carries out the I/Q conversion in numeric field,

Crystal oscillator is exported the input signal of the signal of one road 100MHz as the reference clock signal generator, the clock reference of output 80MHz is delivered to the signal Processing subsystem as clock reference after the filtering of reference clock signal generator process, frequency conversion, amplification, the filtering.

Digital if receiver adopts DIFR6 digital receiver and OPTIC PCI optical fiber interface plate to form.The DIFR6 digital receiver is finished if sampling, digital IQ demodulation, and the transmission of servosignal etc., the digital IQ signal of formation is by Optical Fiber Transmission; The sampling of two-way digital intermediate frequency is carried out in the firm and hard existing optical fiber interface conversion of OPTIC pci interface, finishes digital IQ demodulation, output orthogonal IQ signal; Realize remote data transmission; Transponder pulse is carried out instantaneous sampling, and carry out amplitude and phase correction; Produce the system sequence signal; Transmit servo-drive system control information and system monitoring status information;

Native system adopts the broadband reception design, has saved the automatic frequency tracking device.

Digital receiver produces the timing signal of whole radar, and the digital receiver default setting is 12 and triggers output, is the output of RS422 difference.The time-delay of each triggering, pulsewidth, softwares such as polarity and repetition frequency can be established.Digital if receiver also produces digital AFC or simulation AFC output, the magnetron oscillation frequency of connection control system or the control end of local frequency.Simulate the gain of AFC output and setover adjustable.

The invention effect: the present invention utilizes digital intermediate frequency and first phase compensation technique, improves the radar detection performance; Adopt the broadband reception technology, saved automatic frequency tracking, simplified receiving trap; Adopt the virtual terminal software signal processing technology, use PC directly to carry out real time signal processing, saved special-purpose dsp processor, make simplified equipment, reliable, working service is convenient; Remote data transmission and Remote function have been realized; Novel structure design makes radar more motor-driven, flexible, sets up easy to use.

Important technological parameters:

Frequency of operation: X-band; The detection of a target: the precipitation target of medium tenacity;

Investigative range: distance: 2km～150km; Highly: 0km～20km;

Orientation: 0 °～360 °; The elevation angle: 0 °～90 °; Intensity :≤80dBz;

Speed :+24m/s (apart from 150km); Spectrum width: 16m/s.

Detecting error (standard deviation): distance :≤150m; Angle :≤1 °;

Highly :≤300m (distance＜100km); Intensity :≤1dB;

Speed: 1m/s; Spectrum width: 1m/s.Transmission range: 500m

Resolution distance: 150m; Orientation: 1.5 °; The elevation angle: 1.5 °; Intensity: 1dBz;

Speed: 1m/s; Spectrum width: 1m/s.

On time: normal :≤10min.Stream time: 8h.

Power supply: power supply mode: civil power, oily machine;

Supply voltage: 220 (1 ± 10%) V frequency: 50 (1 soil 3%) H

Full machine power consumption :≤1.5kW.

Environmental baseline requires: temperature :-10 ℃～40 ℃; Relative humidity: 0～95% (35 ℃); Sea level elevation: below the 3000m.Electromagnetic compatibility: connect resistance and be not more than 10 Ω.

Reliability and maintainability: MTBF:500h; MTTR:30min (having under the spare part situation).

Description of drawings

Fig. 1 is a radar composition frame chart of the present invention

Fig. 2 receives the subsystem composition frame chart

Fig. 3 is the digital if receiver composition frame chart

Fig. 4 monitors input MON serial ports sequential chart such as Fig. 4.

Fig. 5 monitors serial CNTL output interface sequential chart

Fig. 6 Portable X wave range Doppler weather radar terminal system

Fig. 7 Doppler radar terminal signaling is handled block diagram

Fig. 8 is the radar transmitted pulse synoptic diagram

Fig. 9 Portable X wave range Doppler weather radar is formed synoptic diagram

Figure 10 the present invention constitutes block diagram

Figure 11 is a High Amplifier Circuit of the present invention

Figure 12 is the radar waveform (distance between two points waveform) that the present invention obtains

Figure 13 is the radar waveform weak (echo area waveform) that the present invention obtains

1. work car 2. Main Control Tanks and power supply cabinets, 3. antennas, 4. antenna pedestals 5. are launched cabinets 6. spikes, 7. lifting jack 8. reels 9. gasoline engine generator groups 10. terminal blocks 11. computer 12.UPS 13. leading-in boxs among Fig. 9

Embodiment

The Portable X wave range Doppler weather radar is made up of 8 subsystems such as antenna feeder subsystem, emission subsystem, reception subsystem, digital if receiver, signal data processing terminal subsystem, servo subsystem, monitoring and power subsystems.The radar composition frame chart is as shown in Figure 1: main subsystem technical scheme:

1, receives subsystem

The formation that receives subsystem is, to the output of antenna feeder subsystem faint high-frequency impulse echoed signal amplify and frequency transformation, echo signal of intermediate frequency is carried out being sent to digital if receiver after filtering is amplified.This subsystem has adopted low noise field effect transistor amplifier, the phase-locked local oscillator of high stable and image frequency rejection mixer, and it is low to have a noise figure, the distinguishing feature that receiving sensitivity is high.Intermediate-frequency receiver is digital intermediate frequency and first phase compensation technique, has improved the performance that tests the speed of radar; Signal Processing is proposed a kind of broadband receiving method, saved automatic frequency tracking, simplified receiving trap; A kind of virtual signal treatment technology is proposed, use PC directly to carry out real time signal processing, saved special-purpose dsp processor, received subsystem and partly form by low noise field effect transistor amplifier (main road amplifier), reference signal amplifier (branch amplifier), phase-locked local oscillator etc.

The main road amplifier by the low noise sound field put, frequency mixer and preposition in put etc. and to form.Be mainly used to select echoed signal, and it is amplified and frequency transformation, the output echo signal of intermediate frequency.

The main road amplifier gain is 30dB, and bandwidth is ± 15MHz to satisfy the needs of broadband reception.

Branch amplifier is that the transmitter master ripple that coupling is come to aperture carries out frequency transformation and amplitude amplification, output intermediate frequency reference signal.It is made up of frequency mixer and intermediate frequency amplifier.The gain of branch amplifier is that 0～10dB is adjustable, satisfies the requirement of data intermediate-frequency receiver to input " Brust " signal (burst) amplitude.

The reference clock signal generator comprises phase-locked local oscillator, and phase-locked local oscillator is made up of crystal oscillator, single-point medium phase locked source and phase-locked oscilaltor, power splitter etc.It is a superhet radar receiver chief component, and it and high-frequency pulse signal mixing produce intermediate-freuqncy signal, export the 100MHz reference signal simultaneously.Reference signal is delivered to the reference clock signal generator.Reference clock signal generator output clock reference is to signal processing system, and as the clock reference of signal Processing signal, setting the clock signal frequency is 80MHz.

Composition frame chart is as shown in Figure 2: principle of work: the faint high frequency echoed signal that receives from the antenna feeder subsystem, behind circulator, discharge tube limiter, send into the main road amplifier that receives subsystem, putting row into by the low noise sound field amplifies, delivers in the image-reject mixer then, echoed signal and local oscillation signal carry out mixing in frequency mixer, 60MHz ± 15MHz the intermediate-freuqncy signal of output, native system adopts the broadband reception design, has saved the automatic frequency tracking device.

Send into the branch amplifier of receiving system by the transmitter master ripple signal of aperture coupling mechanism coupling output, direct conversion becomes intermediate-freuqncy signal, amplifies again, then the intermediate frequency reference signal is sent into the signal Processing subsystem.

Crystal oscillator is exported the input signal of the signal of one road 100MHz as the reference clock signal generator, the clock reference of output 80MHz is delivered to the signal Processing subsystem as clock reference after the filtering of reference clock signal generator process, frequency conversion, amplification, the filtering.

2, digital if receiver

The digital if receiver function

Digital if receiver adopts at a high speed and high-precision a/d converter carries out echo and transponder pulse (main ripple) sampling, utilize Floating-point DSP to carry out transponder pulse and carry out local real time spectral analysis and processing, extract the transponder pulse sample information and carry out amplitude and phase correction, the IQ data (the mutually orthogonal data of two-way) after relevant the processing transfer to strange land signal Processing terminal by optical cable.Digital if receiver mainly contains: compositions such as DIFR6 digital receiver and OPTIC PCI optical fiber interface plate.The DIFR6 digital receiver is finished if sampling, digital IQ demodulation, and the transmission of servosignal etc., the digital IQ signal of formation is by Optical Fiber Transmission; The firm and hard existing optical fiber interface conversion of OPTIC pci interface, and have the analog I output function.The major function of this system is as follows:

A) carry out the sampling of two-way digital intermediate frequency, finish digital IQ demodulation, output orthogonal IQ signal; Realize remote data transmission.Transponder pulse is carried out instantaneous sampling, and carry out amplitude and phase correction;

B) produce the system sequence signal; Transmit servo-drive system control information and system monitoring status information;

Digital if receiver composition frame chart such as Fig. 3 constitute: its formation and principal feature:

A, adopt at a high speed, the A/D transducer of 14 of high precision, echo and transmitted-reference pulse to 60MHz are sampled respectively, in numeric field, carry out the I/Q conversion, and exomonental first phase proofreaied and correct, thereby greatly enlarged the linear dynamic range of radar, improved the detection accuracy of radar.The logarithm that has removed in the traditional analog receiver amplifies circuit such as branch road, agc circuit, STC control, significantly reduces system's discrete element device, improves the reliability of system.The application of digital if receiver makes that the signal transmission is simpler, can carry out the data transmission of remote (500m), has strengthened antijamming capability simultaneously.

B, broadband reception technology can be caught and the tracking target signal in intermediate frequency 45MHz～75MHz scope automatically, thereby have saved automatic frequency tracking device (as the motor tuner), make simplified equipment, have improved the Performance And Reliability of radar.

Principle of work: digital if receiver at first adopts echo IF and main ripple (magnetron) intermediate-freuqncy signal and analyzes, the zero intermediate frequency quadrature IQ signal that processing obtains being concerned with, be sent to the strange land end by the full duplex fibre-optical interface then, the strange land end is furnished with optical fiber interface pci interface and its row communication.Digital received also produces the timing signal of whole radar except finishing conventional intermediate frequency process and analyzing, the digital receiver default setting is 12 and triggers output, is the output of RS422 difference.The time-delay of each triggering, pulsewidth, softwares such as polarity and repetition frequency can be established.Digital if receiver also produces digital AFC or simulation AFC output, is used for the magnetron oscillation frequency or the local frequency of control system.Simulate the gain of AFC output and setover adjustable.Digital receiver has front end monitor-interface and state indication output.Monitor-interface comprises the orientation of serial, pitching input and monitor state input and monitor command output, and it is the RS422 level.The output of RS422 difference and 3 RS422 difference of remaining with 3 are simultaneously imported as spare interface.

IO interface: digital if receiver mainly contains analog interface and digital interface two parts, and analog interface is as follows:

Signal name	Explanation	Interface shape
			IF	The intermediate frequency echo, the amplitude maximum can be ± 14dBm, 50 Europe	SMA JACK FEMALE
BURST/IF2	Transponder pulse intermediate frequency sample or two passage intermediate frequency echoes, sample input range 0-6dBm, and intermediate frequency echo input range is to the maximum+14dBm 50 Europe reference clocks, 80MHz, amplitude 0-6dBm, sinusoidal wave, 50 Europe, phase noise is better than 70dBc@10Hz	SMA JACK FEMALE
			CLK	SMA JACK FEMALE

Digital if receiver is operated in Magnetron Mode, analog input signal is IF echo and IF master's ripple, and requiring the main wave impulse amplitude of input is between-5～6dBm, in order to obtain signal to noise ratio (S/N ratio) preferably, the recommendation amplitude range is 0～6dBm, but amplitude peak can not surpass+6dBm.

The dynamic range of digital receiver is up to more than the 80dB, digital receiver can operate as normal maximal input be+14dBm, but digital receiver has certain nonlinear distortion during greater than+6dBm at the input echo power, leave allowance simultaneously in order to keep complete machine to have bigger dynamic range, recommend about the maximum drive ability Ying Keda+10dBm of front end the IF echo, so high but if machine system do not need to require to dynamic range, then high-end driving force can reduce.

The input range of reference clock can be 0～6dBm, and for fear of the interference of clock signal to the IF signal, the amplitude maximum of reference clock does not surpass+6dBm, is recommended as 0dBm, as strong excessively, should add the external attenuation device.In order to obtain the high-performance of complete machine, reference clock should have the higher index of making an uproar mutually simultaneously.

The digital interface signal:

The digital input/output signal of all of digital if receiver is by a DB37/Female socket and a DB25/Female socket output.

The digital controlled signal of DIFR6 output comprises the working state signal of digital receiver itself, monitoring input/output signal and part stick signal.The output signal that indicates "+-" is the RS422 differential level, and all the other are TTL, but "+" of RS422 output signal end can be used as TTL output.All stick signals or no signal should be unsettled.

Monitoring serial line interface sequential:

Digital if receiver has two synchronous serial interfaces, and one of them exports the CNTL serial ports of monitoring to for control command, and another is for coming self-monitoring ON serial ports.Wherein CNTL output serial ports frame length is 24, and the way of recommendation is that most-significant byte is a command type, and low 16 are the parameter under the corresponding command (digital receiver itself only provides corresponding physical communication passage, need not to know the particular content and the form of data).And the MON input port is 48, and wherein high 16 is the orientation, in 16 for pitching, low 16 monitor states.All serial line interfaces are high-order preceding, and low level is in back (mode moves to left).

Fig. 4: monitoring input MON serial ports sequential chart such as Fig. 4.Send the AZ most significant digit to the AZ lowest order earlier, send EL extreme higher position lowest order again, be at last the state most significant digit to lowest order, all data are effective at rising edge clock, totally 48 of frames.MONSCK clock frequency maximum can be 20MHz.

Terminal is sent most significant digit earlier to totally 24 of CNTL serial ports sequential one frames of monitoring output, and again to lowest order, all data are effective at rising edge clock.Current default output clock frequency is 500KHz, monitoring serial CNTL output interface sequential chart Fig. 5.

Trigger output: digital if receiver has 12 Universal Trigger outputs, and its output level is RS422, output

Socket type is DB25/Female.Power interface: digital receiver works in single 5V power supply, and supply socket is a four-core, and pin assignment is as follows:

1	GND, digitally
		2	+15V
3	+5.2V
		4	+52V
5	-15VV
		6	AGND, simulation ground

The digital if receiver maximum operating currenbt is nearly 2.2A, and we adopt the power supply of 3A analog power.

Because digital receiver is actual to be the large-scale signal processor of high speed, so its consumption to source current is bigger, and the high-frequency digital noise of its generation may be coupled to other places by power supply, so in receiver, the power supply of digital receiver and the power supply of front-end noise susceptibility module are isolated, put the field, preceding medium use is linear power supply independently, to obtain better system performance.

3, signal data processing terminal subsystem

The distinctive feature of Portable X wave range Doppler weather radar terminal utilizes computing machine (PC) to finish the work of live signal data processing, i.e. virtual terminal signal processing technology exactly.This radar terminal process software comprises the real-time processing (containing the data pre-service), data storage of radar signal, shows (graphical user interactive interface) in real time: (1) image shows the setting of (2) condition monitoring (3) radar running parameter), the afterproduct of radar etc.This software has adopted the C Plus Plus exploitation, supports WINDOWS system such as WINDOWS2000/NT/9X operating system.

This software comprises two major parts, the one, be in charge of the device driver of PCI receiving card, and major function is to finish real-time image data is received, cushions and transmits.The 2nd, radar terminal real time signal processing software, major function is that the raw digital signal of real-time collection is handled, generate intensity, speed and spectrum width signal, show radar scanning data and aftertreatment data analysis in real time, the working method of control whole radar and storage echo data.

Fig. 6 is the structured flowchart of whole software system.The structural relation and the function that have clearly reflected two-layer application program among the figure, the radar terminal process software of application layer sends control command by the mode of user interactions to driver, is achieved a butt joint by driver and receives the card control corresponding.After driver obtained the data of real-time monitored by receiving card, notice radar terminal process software carried out signal Processing, storage and demonstration to the data of gathering.

(1), signal Processing major function

From linear I and the Q data that pci data receiving card obtains, the computing of advanced line asynchronous interference eliminated by the amplitude of signal on the more adjacent radar period same distance unit, can be eliminated the interference of other radar to Ben Leida substantially.By the algorithm that large-signal is carried out the amplitude correction, can improve the dynamic range about receiver 6dB, modified value obtains according to actual test result.Carry out land clutter then and suppress to handle,, then adopt the FIR algorithm that clutter is eliminated if adopt PPP to handle; If adopt FFT to handle, then carry out land clutter and suppress to handle at frequency domain.PPP handles and FFT handles and can be selected by the user, obtains the data of intensity, speed and spectrum width.Software is eliminated the interference of second trip echo by different pulses being carried out the mode of phase encoding or random phase, thus the no fuzzy distance of expansion.By dual frequency mode, expansion does not have fuzzy speed.By parameters such as SQI, LOG signal quality is controlled.The singular point Filtering Processing is by the correlativity between the echo, and some singular points of filtering improve the quality of data.Accurate for what guarantee to calculate, total data has all adopted 32 Floating-point Computation and storage, some functions such as sin, log etc. have adopted the floating-point coprocessor of computer CPU inside to calculate, and do not adopt the hardware signal processor usually adopt table look-up and fitting method.Software also possesses influences the function that the factor of measuring accuracy compensates to radar emission power, receiver noise factor, receiver gain etc.See Fig. 7 Doppler radar terminal signaling processing block diagram.

(2), signal Processing major parameter

Systematic parameter:

The long 150m of range bin, 300m; The range bin number is 1000 to the maximum

Measurement range 150km (the 150m storehouse is long); 300km (the 300m storehouse is long)

600km (the 600m storehouse is long); Repetition frequency 200-2000Hz, the frequency continuous variable;

Pulse-width controlled 1,2,4,8 (us).

Intensity is handled:

Processing mode DVIP; The cumulative mean of arteries and veins group is handled in the orientation;

Azimuth averaging number of times 16/32/64/128/256 time is optional; Intensity process range 0-600Km.

Output intensity signal cancellation or do not offset 16bit dB value; Estimation accuracy 1dB.

Base speed and spectrum width processing (PPP, FFT):

I, Q signal are carried out PPP to processing mode or FFT handles

It is optional that PPP handles umber of pulse 16/32/64/128/256

FFT handles 16/32/64/128/256 point (omnidistance FFT) of counting

Output average radial velocity and spectrum width.V, B are the 16Bit normalized value, and spectrum width is estimated to adopt

High-precision divalence correlation method.Estimation accuracy 1m/s

The processing of speed deblurring (APRF, DPRF):

Separate velocity ambiguity and handle irregular repetition APRF or dual complex frequency DPRF, irregular ratio 2/3,3/4

It is several 16/32/64/128/256 that pulse accumulates, estimation accuracy 1m/s.

Reflection differences ZDR:

It is several 16/32/64/128/256 that the valuation of processing mode square-law, pulse accumulate, estimation accuracy 0.2dB

Propagation phase-shift PHDP:

Processing mode PPP, pulse accumulates several 16/32/64/128/256.

Land clutter suppresses:

The processing mode iir filter; Inhibition ability 30～50dB (eight grades optional).Single storehouse: pulse accumulates several 16/32/64/128/256, and the IQ way of output is directly exported undressed distance from digital receiver to the IQ signal, and the phase place that is used for test receiver is steady, Ding Du and check radar time domain echo.

(3), signal processing algorithm

Land clutter suppresses:

For the filtering ground clutter, will adopt the FIR wave filter, coherent I, Q signal are carried out Filtering Processing.The frequency response of FIR wave filter has good shape (low secondary lobe), can obtain bigger clutter and suppress, and the dirigibility of filtering simultaneously is fine, can select different weight coefficient groups for different environment, changes the position of recess.

$y\left(n\right)=\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}h\left(k\right)x(n-k)$

The input signal of FIR wave filter and output signal relation are as follows:

Wherein N represents the filter coefficient number, and h (k) represents filter coefficient.In order to make bank of filters reach good cut-off characteristics, adopt the hamming weighting, reduce the influence of secondary lobe.

Intensity is handled: adopt digital if technology, increased substantially the system linearity dynamic range, thereby receiver can be cancelled in the logarithm and putting, signal processor has also been cancelled the LOG passage, and directly according to I, Q data estimation intensity level, for the intensity of single point signals, square representing of the mould of the plural number that can form by I, Q intuitively:

$Z={|I+\mathrm{jQ}|}^2={\mathrm{SS}}^{*}=I^2{+\mathrm{<figure-callout\; id="2"\; label="Q"\; filenames="A20061009643100201.png,A20061009643100211.png"\; state="\{\{state\}\}">Q</figure-callout>}}^2$

In actual treatment, for the estimated accuracy that satisfies intensity is better than 1db, simultaneously in order to reduce the influence of noise, intensity level need carry out average on the azimuth-range.

$\mathrm{dB}=10\log \stackrel{\&OverBar;}{Z}$

$\stackrel{\&OverBar;}{Z}=\frac{1}{N}\underset{i=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{|I_i+{\mathrm{jQ}}_i|}^2$

Speed and spectrum width are handled:

For improving system's rate accuracy, adopt pulse processor to be carried out the measurement of dobla information.The key distinction of PPP method and FFT method is exactly not need to carry out spectrum analysis.The advantage of PPP method is that the arithmetic facility amount is less, and is highly sensitive, and has certain rate accuracy.

Pulse can be tried to achieve with the mean value of the phase differential of adjacent two echoed signals the average radial velocity that the ultimate principle of handling is based on moving target, that is:

${\stackrel{\&OverBar;}{v}}_r=\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{v}_i=\frac{\mathrm{\&lambda;}}{4\mathrm{\&pi;TN}}\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}({\mathrm{\&phi;}}_{i+1}-{\mathrm{\&phi;}}_i)$

T is the radar repetition period in the formula, and N is relevant average time, φ _iAnd φ _I+1Be respectively the phase place of adjacent two echoed signals, λ is a radar wavelength.

If S _iAnd S _{+ 1}Echoed signal for adjacent two cycles:

$S_i=x_i+{\mathrm{jy}}_i$

$S_{i+1}=x_{i+1}+{\mathrm{jx}}_{i+1}$

${\mathrm{\&phi;}}_{i+1}-{\mathrm{\&phi;}}_i={\mathrm{tg}}^{-1}\left[\frac{x_i{y}_{i+1}-x_{i+1}{y}_i}{x_i{x}_{i+1}+y_i{y}_{i+1}}\right]={\mathrm{tg}}^{-1}\left[\frac{\mathrm{Im}\left\{R\left(T\right)\right\}}{\mathrm{Re}\left\{R\left(T\right)\right\}}\right]$

According to the derivation of equation, can obtain the phase differential of adjacent two echoed signals:

Promptly be the related function R (T) that is spaced apart T.Therefore can obtain average radial velocity is: spectrum width is

$w=\frac{\mathrm{\&lambda;}}{4\mathrm{\&pi;}{T}_s}\sqrt{\frac{2}{3}}\sqrt{\ln \left|\frac{R\left(1\right)}{R\left(2\right)}\right|}$

The deblurring algorithm:

For the radar of a fixed pulse repetition frequency, the fuzzy speed of its maximum nothing can be expressed from the next

$V_{\max }=\&PlusMinus;\frac{1}{4}\mathrm{\&lambda;}\&times;\mathrm{PRF}$

In the formula: V _Max: the fuzzy speed of maximum nothing, λ: radar wavelength, PRF: radar pulse repeats frequency, and its maximum no fuzzy distance is by representing down:

$R_{\max }=\frac{1}{2}{\mathrm{CT}}_r=\frac{1}{2}C\&CenterDot;\frac{1}{\mathrm{PRF}}$

In the formula: R _Max: maximum no fuzzy distance, C: the light velocity

So its maximum product that does not have fuzzy speed and maximum no fuzzy distance is

R _maxV _max＝±λC/8

Following formula the right is a constant. therefore, will exist speed covering and distance to cover the contradiction that can not take into account sometimes.In order to overcome this contradiction, system disposition speed and apart from deblurring algorithm (APRF and DPRF).

The APRF algorithm:

According to speed formula

$V=\frac{\mathrm{\&lambda;\&phi;}}{4\mathrm{\&pi;Tr}}$

(π, in the time of π), velocity estimation will produce fuzzy when the φ scope exceeds.APRF adopts the recurrent interval to be followed successively by T1 and T2, and (pulse of T1 ≠ T2) is to meteorological target sample (general T1＜T2), this method is the development to PPP in essence, and its radar transmitted pulse string as shown in Figure 8)

When this method was asked correlation, two correlations were respectively to S _2kAnd S _2k+1Sequence is carried out, as follows two formulas

$R\left(T1\right)=\frac{1}{N}\underset{K=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}{S}_{2K+1}{S}_{2K}^{*}$

$R\left(T2\right)=\frac{1}{N}\underset{K=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}{S}_{2(K+1)}{S}_{2K+1}^{*}$

In the formula

R (T1): the auto-correlation that is divided into the T1 train of impulses mutually

R (T2): the auto-correlation that is divided into the T2 train of impulses mutually

It is respectively that pulse when being T1 and T2 pulse-recurrence time detects average velocity that above-mentioned two formulas are equivalent to, and as detecting with R (T1), it does not have fuzzy velocity range and is

V _max1＝±λ/4T1

When in like manner, only using R (T2) to detect

V _max2＝±λ/4T2

If but utilize R (T1) and differing of R (T2) to detect, and can enlarge does not have fuzzy speed, and the velocity estimation formula is:

$V=\frac{\mathrm{\&lambda;}}{4\mathrm{\&pi;}(T2-T1)}\left\{\arg \right[R\left(T2\right)]-\arg [R\left(T1\right)\left]\right\}$

Because T2-T1 can be than T1, any one among the T2 is little, as establishes

φ＝arg[R(T2)]-arg[R(T1)]

Belong to for φ equally then that (π, π), its velocity estimation Vmax will enlarge.Promptly

$V=\frac{\mathrm{\&lambda;\&phi;}}{4\mathrm{\&pi;}{T}_2(1-K)}$

K=T in the formula ₁/ T ₂

When K=3/4, Vmax can reach 3Vmax1 or 4Vmax2.Obviously, the difference of T1 and T2 is more little, and it is just big more not have fuzzy speed, but its estimation variance will strengthen simultaneously, and therefore, its difference can not be too little, otherwise the estimation that obtains will be meaningless.Simultaneously for distance

$R_{\max }=\frac{C(\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="A20061009643100171.png,A20061009643100201.png"\; state="\{\{state\}\}">T</figure-callout>}1+T2)}{2}$

When therefore, the expansion of this method has fuzzy speed no fuzzy distance there is not to a certain degree expansion yet.This is because for outside the Rmax during driftlessness, when calculating R (T1) and R (T2), have only one of them sampling to existence, therefore, there is not influence in the calculating of R (T1) and R (T2).

The result is as follows according to Theoretical Calculation:

PRF1＝ 750 Hz				PRF2＝ 1000 Hz
							Speed
1=	6.05	m/s		Apart from 1=	200.00	km
							Speed
2=	8.06	m/s		Apart from 2=	150.00	km
			Not fuzzy speed				32.26	m/s	Fuzzy distance not	350.00	km

PRF1＝ 1000 Hz				PRF2＝ 1500 Hz
							Speed
1=	8.06	m/s		Apart from 1=	150.00	km
							Speed
2=	12.10	m/s		Apart from 2=	100.00	km
			Not fuzzy speed				36.29	m/s	Fuzzy distance not	250.00	km

The Portable X wave range Doppler weather radar is mainly by 1. work car 2. Main Control Tanks among Fig. 9 and power supply cabinet 3. antennas 4. antenna pedestals 5. emission cabinets 6. spikes 7. lifting jack 8. reels 9. gasoline engine generator groups 10. terminal blocks 11. computer 12.UPS 13. leading-in boxs.Wherein, antenna, antenna pedestal, emission cabinet, Main Control Tank and power supply cabinet, spike are combined into an integral body, the front end of construction system; And the rear end of computer terminal and IVECO transport car 1 construction system.The composition of radar divides from telecommunication and is made up of eight subsystems, is respectively:

The antenna feeder subsystem; The emission subsystem; Receive subsystem; Digital if receiver;

Servo subsystem; The monitoring subsystem; Signal data processing terminal subsystem; Power subsystem.

4, radar is divided into from the structure composition: five parts such as antenna assembly, emission cabinet, Main Control Tank and power supply cabinet, radar terminal, gasoline engine generator group.The General Arrangement of radar as shown in Figure 9.

The data processing subsystem scheme: data processing subsystem is made up of a high-performance computer on hardware, and utility appliance is a HUB and a UPS uninterrupted power source.On software, data processing subsystem is made up of four parts, is respectively: receive program, signal Processing terminal program, afterproduct handling procedure and four parts of Product Management System in real time and form.

(1), the scheme of real-time handler

(1), the function of real-time handler

A, finish the control of radar scanning mode, as PPI, RHI, SPPI, CAPPI scanning, crawl is accurately controlled up and down;

B, support that (bmp, storage gif) support distance to correct and the noise gate setting to scan image, support the printout of image with data or graphics mode;

C, realize for the realtime monitoring of each extension set of radar and finish warning;

D, realize calibrating function, guarantee that antenna can be parked in the optional position that the user sets, the protection antenna for radar bearing and pitching;

E, realize for the realtime monitoring of each subsystem of radar and finish warning;

F, electronics map vector are supported, support vector to amplify, real-time positioning, map delamination, map stack in real time;

G, in addition, also have with the many key elements of screen show, local amplify, receive GPS geography information, operator with producing function such as management.

(2), the interface of real-time handler

The interface of real-time handler is as shown below:

In the top of figure is menu, and middle major part is the display graphics part, below be prompt panel, comprising: control in real time, sweep parameter, system state panel, four quick panels of historical summary.

(3), receive the interface scheme of program in real time:

The interface of reception program is as follows in real time:

(2), signal handler scheme

(1), the function of signal handler

The major function of signal Processing terminal program is to be in charge of the device driver of PCI receiving card, finishes that real-time image data is received, cushions and transmits, and police radar state and aerial position.

In work, this program is responsible for real-time image data is received, cushions and transmits, and police radar state and aerial position, and gives real-time reception program with data.The parameter of this program is clicked " beginning to gather " button after setting completed, minimizes then, is placed on running background.

(2), the scheme at interface is as shown below:

This program also can be carried out aspect operations such as a day line traffic control, switch transmitter to radar, and these operations are the same with real-time reception program.In the left side, main interface the first half is the button of radar antenna control, and the latter half is that the signal processor state shows.Right half part at main interface is a patterned oscillograph, can observe the data that receive.

Time-controlled option is arranged under system's Control-Menu, click this option and open interface as shown below, can control the mode of operation of data intermediate-frequency receiver.Comprise controls such as tupe, pulse accumulation number, repetition frequency, trigger pulse.

Time-controlled interface:

(3), afterproduct handling procedure scheme

(1), the function of afterproduct program

Secondary treatment system mainly is further processed the data that receive in real time, obtains more weather information.Major product is as follows:

☆ master data product: radar reflectivity factor R; Average doppler velocity V;

Spectrum width SW; Real-time PPI (planimetric position demonstration); RHI (distance highly shows);

Non real-time PPI, RHI, CASPPI (demonstration of contour planimetric position);

VCS (any direction vertical section); ETSPPI (echo is risen the planimetric position and shown).

☆ radar reflection factor field product; The combined reflected rate factor (CR);

Combined reflected rate factor isoline; Echo top (ET);

Echo top isoline (ETC); Hail index (HI); The anti-water yield (OHP) of accumulation in 1 hour;

3 hours accumulative rainfall amounts (THP); The total accumulative rainfall amount of storm (STP);

Vertical integration hydraulic pressure water cut (VIL); Weak echo region (WER); 1 hour precipitation digital array (DPA).

☆ wind field product

Velocity Azimuth shows (VAD); VAD vertically-supplying air profile (VWP) and time distribute;

The relative average radial velocity of storm (SRM); Spout vortex feature (TVS);

The speed volume is handled (VVP)---and horizontal wind speed shows; Mesoscale cyclone (M).

The comprehensive product of ☆

Storm structure analysis (SS); User Alarms information (VAM);

Storm forecast information---strong weather probability (SWP); Storm tracked information (STI).

The ☆ graphics process

Single-image, many pictures, animation, local amplification, roaming, filtering.

(2), afterproduct handling procedure interface scheme

The product that part afterproduct handling procedure generates is as follows:

A, any direction vertical section; B, point-to-point transmission range finding arbitrarily; C, weak echo region

In Figure 11 circuit, the high frequency echoed signal is added to image frequency rejection mixer (being made by microstrip circuit) with local oscillation signal after low noise field effect transistor 60MHz amplifies, through mixing output intermediate-freuqncy signal, the output echo signal of intermediate frequency is to digital if receiver behind the amplification of process two-stage and filtering Z1, the Z2.Characteristics are to adopt low noise field effect transistor amplifier, image frequency rejection mixer, and noise figure is low, image frequency inhibition degree height, gain flatness is good.

Embodiments of the invention obtain Figure 12 distance between two points waveform and Figure 13 REA(radar echoing area) waveform.

Claims (9)

1, the signal processing method of Portable X wave range Doppler weather radar: on the hardware foundation that constitutes by antenna feeder subsystem, emission subsystem, reception subsystem, digital if receiver, signal data processing terminal subsystem, servo subsystem, monitoring and power subsystem, it is characterized in that receiving subsystem signal Processing is adopted broadband receiving method, with low noise field effect transistor amplifier constitute the main road amplifier, with reference signal amplifier and phase-locked local oscillator, phase-locked local oscillator of high stable and image rejection mixer constitute and receive subsystem; Adopt broadband reception, in intermediate frequency 45MHz～75MHz scope, catch automatically and the tracking target signal; The main road amplifier by the low noise sound field put, frequency mixer and preposition in put etc. and to form; Be mainly used to select echoed signal, and it is amplified and frequency transformation, the output echo signal of intermediate frequency;

The reference signal amplifier is that branch amplifier is made up of frequency mixer and intermediate frequency amplifier; The transmitter master ripple that coupling is come to aperture carries out frequency transformation and amplitude is amplified, and direct conversion becomes intermediate-freuqncy signal, and output intermediate frequency reference signal is sent into the signal Processing subsystem;

The reference clock signal generator comprises phase-locked local oscillator, and phase-locked local oscillator is made up of crystal oscillator, single-point medium phase locked source and phase-locked oscilaltor, power splitter etc.; It and high-frequency pulse signal mixing produce intermediate-freuqncy signal, export the 100MHz reference signal simultaneously; Reference signal is delivered to the reference clock signal generator; The clock reference of output 80MHz is delivered to the signal Processing subsystem as clock reference after the filtering of reference clock signal generator process, frequency conversion, amplification, the filtering;

The faint high frequency echoed signal that receives from the antenna feeder subsystem, behind circulator, discharge tube limiter, send into the main road amplifier that receives subsystem, carry out frequency transformation and put row into by the low noise sound field and amplify, deliver in the image-reject mixer then, echoed signal and local oscillation signal carry out mixing in frequency mixer, the 60MHz+15MHz intermediate-freuqncy signal of output; Echo signal of intermediate frequency is carried out being sent to digital if receiver after filtering is amplified.

2, the signal processing method of X-band Doppler radar according to claim 1: it is characterized in that using the virtual signal disposal route, use PC directly to carry out real time signal processing.

3, the signal processing method of X-band Doppler radar according to claim 1: it is characterized in that digital if receiver adopts at a high speed and high-precision a/d converter carries out echo and transponder pulse if sampling, numeral IQ demodulation utilizes Floating-point DSP to carry out transponder pulse to carry out local real time spectral analysis and processing, extract the transponder pulse sample information and carry out amplitude and phase correction, produce the system sequence signal; Transmit servo-drive system control information and system monitoring status information; The mutually orthogonal data of two-way after relevant the processing are that the IQ data transfer to strange land signal Processing terminal by optical cable.

4, the signal processing method of X-band Doppler radar according to claim 3: it is characterized in that digital if receiver has two synchronous serial interfaces, one of them exports the CNTL serial ports of monitoring to for control command, and another is for coming self-monitoring ON serial ports.

5, the signal processing method of X-band Doppler radar according to claim 4: it is characterized in that wherein CNTL output serial ports frame length is 24, the way of recommendation is that most-significant byte is a command type, low 16 are the parameter under the corresponding command, and the MON input port is 48, wherein high 16 is the orientation, in 16 for pitching, low 16 monitor states.All serial line interfaces are high-order preceding, and low level is in back (mode moves to left); Monitoring input ON serial ports sequential is as follows.Send the AZ most significant digit to the AZ lowest order earlier, send EL extreme higher position lowest order again, be at last the state most significant digit to lowest order, all data are effective at rising edge clock, totally 48 of frames; The MONSCK clock frequency is 20MHz to the maximum.

6, the signal processing method of X-band Doppler radar according to claim 4: it is characterized in that digital receiver has front end monitor-interface and state indication output; Monitor-interface comprises the orientation of serial, pitching input and monitor state input and monitor command output, and it is the RS422 level; The output of RS422 difference and 3 RS422 difference of remaining with 3 are simultaneously imported as spare interface.

7, Portable X wave range Doppler weather radar is made up of antenna feeder subsystem, emission subsystem, reception subsystem, digital if receiver, signal data processing terminal subsystem, servo subsystem, monitoring and power subsystem; Described reception subsystem comprises low noise field effect transistor amplifier, reference signal amplifier composition; It is characterized in that the main road amplifier by the low noise sound field put, the phase-locked local oscillator of high stable suppresses frequency mixer mutually with mirror, frequency mixer and preposition in composition such as put; Branch amplifier is made up of frequency mixer and intermediate frequency amplifier; The transmitter master ripple that coupling is come to aperture carries out frequency transformation and amplitude is amplified, and direct conversion becomes intermediate-freuqncy signal, and output intermediate frequency reference signal is sent into the signal Processing subsystem; The faint high frequency echoed signal that receives from the antenna feeder subsystem, behind circulator, discharge tube limiter, send into the main road amplifier that receives subsystem, putting row into by the low noise sound field amplifies, delivers in the image-reject mixer then, echoed signal and local oscillation signal carry out mixing in frequency mixer, 60MHz ± 15MHz the intermediate-freuqncy signal of output carries out echo signal of intermediate frequency to be sent to digital if receiver after filtering is amplified; The reference clock signal generator comprises phase-locked local oscillator, and phase-locked local oscillator is made up of crystal oscillator, single-point medium phase locked source and phase-locked oscilaltor, power splitter etc.; Produce intermediate-freuqncy signal with the high-frequency pulse signal mixing, export the 100MHz reference signal simultaneously; Reference signal connects the reference clock signal generator; Digital if receiver adopts the A/D transducer of 14 of high speed, high precision that echo and the transmitted-reference pulse of 60MHz are sampled respectively, in numeric field, carry out the I/Q conversion, crystal oscillator is exported the input signal of the signal of one road 100MHz as the reference clock signal generator, the clock reference of output 80MHz is delivered to the signal Processing subsystem as clock reference after the filtering of reference clock signal generator process, frequency conversion, amplification, the filtering.

8, Portable X wave range Doppler weather radar according to claim 7 is characterized in that digital if receiver adopts if sampling, digital IQ demodulation, and the DIFR6 digital receiver of the biography of servosignal and OPTIC PCI optical fiber interface plate are formed; The digital IQ signal that forms is by Optical Fiber Transmission; The sampling of two-way digital intermediate frequency is carried out in the firm and hard existing optical fiber interface conversion of OPTIC pci interface, finishes digital IQ demodulation, output orthogonal IQ signal; Realize remote data transmission; Transponder pulse is carried out instantaneous sampling, and carry out amplitude and phase correction; Produce the system sequence signal; Transmit servo-drive system control information and system monitoring status information.

9, Portable X wave range Doppler weather radar according to claim 7 is characterized in that digital receiver exports the timing signal of whole radar, and the digital receiver default setting is 12 and triggers output, is the output of RS422 difference; Digital if receiver is exported digital AFC or simulation AFC output, is used for the magnetron oscillation frequency of connection control system or the control end of local frequency.

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