CN102540156B - Wind profile radar signal and data processing method based on two channels - Google Patents

Abstract

The invention discloses a wind profile radar signal and data processing method based on two channels. The wind profile radar signal and data processing method is implemented by a signal processor and a data terminal, and comprises the specific steps that: the signal processor sets two groups of processing parameters; 2, the signal processor generates two groups of power spectrum data; 3, the data terminal processes the two groups of power spectrum data respectively; and 4, the data terminal selects a processing result. Therefore, wind profile radar signal and data processing based on the two channels is implemented. The method has the advantages that: the data output rate of a wind profile radar system is not changed; the new increased processing load is relatively small; the method is easily implemented; and the extraction capacity and the estimation precision of a wind profile radar to weak signals are improved effectively.

Description

A kind of based on twin-channel Wind profile radar signal and data processing method

Technical field

The present invention relates to a kind of radar signal and data processing method, particularly a kind of based on twin-channel Wind profile radar signal and data processing method.

Background technology

Current Wind profile radar signal and data processing method realize based on signal processor and data terminal, and the key step that signal is processed is: coherent accumulation, and by N _cIthe individual echoed signal of in succession returning is carried out coherent accumulation, wherein, and N _cIbe called coherent accumulation number; Spectral transformation, by N _fFTechoed signal after individual coherent accumulation is carried out fast fourier transform (FFT), obtains a power spectral density function, N _fFTbeing called FFT counts; Spectrum is average, by N _sPCindividual power spectral density function averages, and obtains a new average power spectral density function (being designated hereinafter simply as power spectrum), N _sPCbe called spectral average.Afterwards, data terminal is carried out Spectrum data processing to power spectrum, obtains echo power Pr, Doppler shift f _d, speed spectrum width σ and signal to noise ratio snr.

In above signal processing and Spectrum data processing, coherent accumulation is the committed step that wind profile radar is realized weak signal extraction, and its major function is to improve signal to noise ratio (S/N ratio), in theory, and N _cIinferior coherent accumulation can improve signal to noise ratio (S/N ratio) N _cIdoubly.The limit that coherent accumulation improves signal to noise ratio (S/N ratio) depends primarily on the auto-correlation time of return signal in the phase stability of Wind Profiler Radar System itself and atmosphere, when system phase degree of stability meets the demands, the number of times that carries out coherent accumulation is main relevant with auto-correlation time and the recurrent interval of atmosphere return signal.The wavelength that in atmosphere, the auto-correlation time of return signal selects with atmospheric condition and wind profile radar is relevant, for troposphere wind profiler radar (pattern-band), the auto-correlation time selects 0.15～0.45 second, and the PBL wind profile radar (L-band) is selected 0.05～0.15 second.

Because atmospheric condition is ever-changing, when coherent accumulation time that system adopts and return signal the auto-correlation time, difference was larger time, theory and practice all shows, can affect the effect of coherent accumulation, is unfavorable for the extraction of feeble signal.Although in Wind Profiler Radar System design, coherent accumulation number has certain selectable range, for carrying out in actual detection preferably, but most wind profile radar all take one group fixedly processing parameter automatically move, though part often changes processing parameter for the wind profile radar of studying for research needs, and can not automatically adapt to different atmospheric conditions.

Summary of the invention

The object of the present invention is to provide a kind of based on twin-channel Wind profile radar signal and data processing method, while solving traditional Wind profile radar signal processing, the coherent accumulation time existing and return signal auto-correlation time can not Auto-matchings, are unfavorable for the problem of weak signal extraction.

Based on twin-channel Wind profile radar signal and a data processing method, based on signal processor and data terminal, realize, its concrete steps are:

First step signal processor arranges two groups of processing parameters

For the auto-correlation time, troposphere wind profiler radar is selected respectively 0.15～0.225,0.3～0.45 second, and the PBL wind profile radar is selected respectively 0.05～0.075,0.1～0.15 second.Auto-correlation time and wave beam residence time are respectively:

τ＝PRT×N _CI×N _FFT (1)

T _BEAM＝PRT×N _CI×N _FFT×N _SPC (2)

In formula, τ is the auto-correlation time, T _bEAMfor wave beam residence time, PRT is the pulse repetition time, N _cIfor coherent accumulation number, N _fFTfor FFT counts, N _sPCfor spectral average.

Determine after wave beam residence time, according to select two groups of auto-correlation times, keep pulse repetition time, FFT to count constant, calculate two groups of different processing parameters.Wherein, the coherent accumulation number of first group of parameter is two times of second group of parameter, and spectral average is 1/2nd of second group of parameter.

Second step signal processor generates two groups of power spectrum datas

Signal processor, to identical echoed signal, according to two groups of processing parameters, carries out respectively coherent accumulation, spectral transformation, spectrum average treatment successively, generates two groups of power spectrum datas.Two groups of power spectrum datas have different not fuzzy speed and velocity resolution, are respectively:

V _MAX＝λ/(4×PRT×N _CI) (3)

V _MIN＝λ/(2×PRT×N _CI×N _FFT) (4)

In formula, V _mAXfor not fuzzy speed, V _mINfor velocity resolution, λ is radar wavelength.

The 3rd step data terminal is carried out respectively the processing of two groups of power spectrum datas

Data terminal, to two groups of power spectrum datas, is used identical processing parameter to carry out respectively square estimation, obtains echo power, Doppler shift, speed spectrum width and signal to noise ratio (S/N ratio).Formula is:

$\mathrm{Pr}=\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{p}_i---\left(5\right)$

$f_d=\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{f}_i{p}_i/\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{p}_i---\left(6\right)$

$\mathrm{\σ}=\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{f_i}^2{p}_i/\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{p}_i---\left(7\right)$

$\mathrm{SNR}=10\log \left(\frac{\underset{i=1}{\overset{h}{\mathrm{\Σ}}}{p}_i}{P_n}\right)---\left(8\right)$

In formula, Pr is echo power, f _dfor Doppler shift, σ speed spectrum width, SNR is signal to noise ratio (S/N ratio), P _nfor noise power, p _ibe i point performance number, f _iit is i point Doppler shift value.

The 4th step data terminal is carried out result and is chosen

Data terminal is the result of two groups of power spectrum datas relatively, according to the high person's priority principle of signal to noise ratio (S/N ratio), chooses wind spectrum discrimination and the estimated result of high s/n ratio.Formula is:

SNR1≥SNR2，Pr＝Pr1，f _d＝f _d1，σ＝σ1，SNR＝SNR1

SNR1＜SNR2，Pr＝Pr2，f _d＝f _d2，σ＝σ2，SNR＝SNR2 (9)

So far, realized based on twin-channel Wind profile radar signal and data processing.

This method adopts two kinds of different coherent accumulations and incoherent accumulation number, solves coherent accumulation and does not mate with real atmosphere situation, causes signal and data processing to extract difficult problem to weak echo signal.The advantage of the method is not change Wind Profiler Radar System output data rate, newly-increased processing load is less, realization is simple, can effectively strengthen wind profile radar to the extractability of feeble signal and estimated accuracy.

Embodiment

Based on twin-channel Wind profile radar signal and a data processing method, based on signal processor and data terminal, realize, its concrete steps are:

First step signal processor arranges two groups of processing parameters

For the auto-correlation time, troposphere wind profiler radar is selected respectively 0.2,0.4 second, and the PBL wind profile radar is selected respectively 0.065,0.13 second.Auto-correlation time and wave beam residence time are respectively:

τ＝PRT×N _CI×N _FFT (1)

T _BEAM＝PRT×N _CI×N _FFT×N _SPC (2)

In formula, τ is the auto-correlation time, T _bEAMfor wave beam residence time, PRT is the pulse repetition time, N _cIfor coherent accumulation number, N _fFTfor FFT counts, N _sPCfor spectral average.

Determine after wave beam residence time, according to select two groups of auto-correlation times, keep pulse repetition time, FFT to count constant, calculate two groups of different processing parameters.Wherein, the coherent accumulation number of first group of parameter is two times of second group of parameter, and spectral average is 1/2nd of second group of parameter.

Second step signal processor generates two groups of power spectrum datas

Signal processor, to identical echoed signal, according to two groups of processing parameters, carries out respectively coherent accumulation, spectral transformation, spectrum average treatment successively, generates two groups of power spectrum datas.Two groups of power spectrum datas have different not fuzzy speed and velocity resolution, are respectively:

V _MAX＝λ/(4×PRT×N _CI) (3)

V _MIN＝λ/(2×PRT×N _CI×N _FFT) (4)

In formula, V _mAXfor not fuzzy speed, V _mINfor velocity resolution, λ is radar wavelength.

The 3rd step data terminal is carried out respectively the processing of two groups of power spectrum datas

Data terminal, to two groups of power spectrum datas, is used identical processing parameter to carry out respectively square estimation, obtains echo power, Doppler shift, speed spectrum width and signal to noise ratio (S/N ratio).Formula is:

$\mathrm{Pr}=\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{p}_i---\left(5\right)$

$f_d=\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{f}_i{p}_i/\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{p}_i---\left(6\right)$

$\mathrm{\σ}=\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{f_i}^2{p}_i/\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{p}_i---\left(7\right)$

$\mathrm{SNR}=10\log \left(\frac{\underset{i=1}{\overset{h}{\mathrm{\Σ}}}{p}_i}{P_n}\right)---\left(8\right)$

In formula, Pr is echo power, f _dfor Doppler shift, σ speed spectrum width, SNR is signal to noise ratio (S/N ratio), P _nfor noise power, p _ibe i point performance number, f _iit is i point Doppler shift value.

The 4th step data terminal is carried out result and is chosen

Data terminal is the result of two groups of power spectrum datas relatively, according to the high person's priority principle of signal to noise ratio (S/N ratio), chooses wind spectrum discrimination and the estimated result of high s/n ratio.Formula is:

SNR1≥SNR2，Pr＝Pr1，f _d＝f _d1，σ＝σ1，SNR＝SNR1

SNR1＜SNR2，Pr＝Pr2，f _d＝f _d2，σ＝σ2，SNR＝SNR2 (9)

So far, realized based on twin-channel Wind profile radar signal and data processing.

Claims (1)

1. based on twin-channel Wind profile radar signal and a data processing method, based on signal processor and data terminal, realize, it is characterized in that concrete steps are:

First step signal processor arranges two groups of processing parameters

For the auto-correlation time, troposphere wind profiler radar is selected respectively 0.15～0.225,0.3～0.45 second, and the PBL wind profile radar is selected respectively 0.05～0.075,0.1～0.15 second; Auto-correlation time and wave beam residence time are respectively:

τ＝PRT×N _CI×N _FFT (1)

T _BEAM＝PRT×N _CI×N _FFT×N _SPC (2)

In formula, τ is the auto-correlation time, T _bEAMfor wave beam residence time, PRT is the pulse repetition time, N _cIfor coherent accumulation number, N _fFTfor FFT counts, N _sPCfor spectral average;

Determine after wave beam residence time, according to select two groups of auto-correlation times, keep pulse repetition time, FFT to count constant, calculate two groups of different processing parameters; Wherein, the coherent accumulation number of first group of parameter is two times of second group of parameter, and spectral average is 1/2nd of second group of parameter;

Second step signal processor generates two groups of power spectrum datas

Signal processor, to identical echoed signal, according to two groups of processing parameters, carries out respectively coherent accumulation, spectral transformation, spectrum average treatment successively, generates two groups of power spectrum datas; Two groups of power spectrum datas have different not fuzzy speed and velocity resolution, are respectively:

V _MAX＝λ/(4×PRT×N _CI) (3)

V _MIN＝λ/(2×PRT×N _CI×N _FFT) (4)

In formula, V _mAXfor not fuzzy speed, V _mINfor velocity resolution, λ is radar wavelength;

The 3rd step data terminal is carried out respectively the processing of two groups of power spectrum datas

Data terminal, to two groups of power spectrum datas, is used identical processing parameter to carry out respectively square estimation, obtains echo power, Doppler shift, speed spectrum width and signal to noise ratio (S/N ratio); Formula is:

$\mathrm{Pr}=\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{p}_i---\left(5\right)$

$f_d=\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{f}_i{p}_i/\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{p}_i---\left(6\right)$

$\mathrm{\σ}=\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{f_i}^2{p}_i/\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{p}_i---\left(7\right)$

$\mathrm{SNR}=10\log \left(\frac{\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{p}_i}{P_n}\right)---\left(8\right)$

In formula, Pr is echo power, f _dfor Doppler shift, σ speed spectrum width, SNR is signal to noise ratio (S/N ratio), P _nfor noise power, p _ibe i point performance number, f _iit is i point Doppler shift value;

The 4th step data terminal is carried out result and is chosen

Data terminal is the result of two groups of power spectrum datas relatively, according to the high person's priority principle of signal to noise ratio (S/N ratio), chooses wind spectrum discrimination and the estimated result of high s/n ratio; Formula is:

If SNR1>=SNR2, shellfish Pr=Pr1, f _d=f _d1, σ=σ 1, SNR=SNR1

If SNR1 < is SNR2, shellfish Pr=Pr2, f _d=f _d2, σ=σ 2, SNR=SNR2 (9)

So far, realized based on twin-channel Wind profile radar signal and data processing.