CN105353360A - Radar seeker signal processing simulated analysis method and system - Google Patents

Abstract

The invention relates to a radar seeker signal processing simulated analysis method and system. A data collector collects sum and difference signals, after down conversion by a radar receiver, at a high speed via an optical port of a seeker signal processor, and stores the sum and difference signals, the collected data is introduced into a control computer via a network cable, corresponding signal processing simulated analysis is carried out, and a processing result is reflected in the data and figure forms. Thus, the system can analyze the seeker data needless of purely relying on original MATLAB simulation analysis software and the like, and C++ language based self-programmed processing algorithms of the system can be transplanted to DSP and implemented, and the DSP algorithm can be improved and verified.

Description

A kind of radar seeker simulation of Signal Processing analytical approach and system

Technical field

The present invention relates to a kind of radar seeker signal transacting and data processing field, be specifically related to a kind of radar seeker signal transacting and data processing simulating analysis.

Background technology

The radar seeker development stage, need to carry out a large amount of signal transacting and the work of data processing simulation analysis, in order to verification algorithm performance or fault location.When carrying out target seeker field trial, in order to evaluating objects characteristic better or find hardware problem, need to carry out analyzing to target seeker echo data comprehensively and in depth, use the software and hardware of target seeker self then can not complete this work, can only by gathering target seeker echo data, then simulation analysis software be used to carry out off-line analysis to these real data of adopting.

Off-line analysis is carried out to target seeker data and often first gathers the intermediate frequency echo data after receiver down coversion by data acquisition unit, this needs guidance header signal treatment tool for the basic data output interface such as serial ports or network interface, and the acquisition speed of conventional serial ports or network interface can not meet the speed acquisition requirement of mass data.Designer needs to use certain simulation analysis software (as MATLAB, SPW and DSPStation etc.) to be loaded into and Analysis of programming these data afterwards, and with the form display analysis result of picture or curve, as Fig. 1.If need research or verify new data processing algorithm, coding (as MATLAB language etc.) is then needed to verify, do not accomplish to be written as with settling at one go the C language or C Plus Plus form that digital signal processor (DSP) can be supplied to perform, this just means that the off-line data process leaving the data analysis software radar seekers such as MATLAB will be difficult to realize.Therefore, we design a kind of the radar seeker signal transacting and the data processing simulating analysis that do not rely on third party's simulation analysis software, wherein self-editing simulation analysis software is the core component of system, simplifies original off-line data treatment scheme and improves data analysis efficiency.

Summary of the invention

The technical matters solved

In order to avoid the deficiencies in the prior art part, the present invention proposes a kind of radar seeker simulation of Signal Processing analytical approach and system.

Technical scheme

A kind of radar seeker simulation of Signal Processing analytical approach, is characterized in that step is as follows:

Step 1: seeker antenna receiving target reflection echo, downconverts to an intermediate-freuqncy signal by radar return, an intermediate-freuqncy signal is converted to two intermediate-freuqncy signals again, two intermediate-freuqncy signals being carried out digital-to-analog conversion is digital signal;

Step 2: by digital signal and one group of orthogonal local oscillation sequence cos (w ₀n) with sin (w ₀n) be multiplied, then by digital low-pass filtering LPF filtering HFS, export in-phase component x _i(n) and quadrature component x _q(n);

Step 3: by input signal x (n)=x _i(n)+j*x _q(n) and matched filter h (n)=h _i(n)+j*h _qn () is carried out convolution and is obtained process of pulse-compression signal:

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

Wherein, n is current sampling point, and N is sample sequence length, and i is convolution iteration sequence number;

Step 4: paired pulses compression processing signals is carried out rearrangement and obtained y ' (n), and the method for described rearrangement is that the echo in different repetition cycle is reset by range unit;

Step 5: FFT computing is carried out to the y ' (n) reset:

$Y^{\′}\left(k\right)=\underset{n=1}{\overset{M}{\Σ}}{y}^{\′}\left(n\right)e^{-j\frac{2\mathrm{\π}}{N}}\left(n-1\right)\left(k-1\right)$

Wherein, y ' (n) is input signal, and M is that FFT counts, and k is current sequence number, and span is 0 ~ M-1, Y ' (k) is sequence after Current Transform;

Step 6: modular arithmetic is asked to Y ' (k), CFAR detection process CFAR is carried out to the modulus value of Y ' (k) and obtains multiple target, meet the target range scope of setting, velocity range, selection signal to noise ratio (S/N ratio) is maximum in angle error target at the same time as tracking target.

Step 6 replaces with asks modular arithmetic to Y ' (k), averages by Doppler's passage to the modulus value within the scope of the target range of satisfied setting, and the Doppler's channel number finding Largest Mean corresponding is clutter center.

A kind of radar seeker simulation of Signal Processing analytic system, is characterized in that comprising the bookbinding of target seeker, data acquisition unit, reading data module, mode of operation and parameter module, signal processing module and the result that connect successively shows and data storage module; Data acquisition unit gathers the echo data of target seeker, read data module to read echo data, mode of operation and parameter bookbinding module carry out mode of operation selection and setting parameter to echo signal processing, signal processing module carries out signal transacting to echoed signal, and echo signal processing result carries out showing and data preservation by result display and data storage module.

Beneficial effect

A kind of radar seeker simulation of Signal Processing analytical approach that the present invention proposes and system, beneficial effect had compared with prior art: result is visual, flow process is simplified, test facilitation, storing high-speed, checking high efficiency.Signal transacting in DSP and data handling procedure partial results can show with forms such as numeral or figures by the present invention, facilitate designer to carry out debugging and pinpointing the problems, processing procedure Observable; Meanwhile, simplify original guidance header signal collection and simulation analysis process, no longer rely on MATLAB third party's simulation analysis software, saved time cost, simplified flow process; Secondly, change the present situation that existing DSP cannot observe inter-process result and data during target seeker internal operation, facilitate designer to carry out target seeker fault diagnosis and process monitoring, be easy to test; Again, fiber-optic transmission rate is apparently higher than conventional asynchronous serial ports, and stability is higher, and transmission range is longer, data store and transmission speed faster; Finally, designer is facilitated to carry out the work such as the checking of signal transacting and data processing new algorithm and debugging, checking means convenient and efficient more.

This software specifically with use MATLAB programme compared with advantage be: first, the simulation analysis software internal code system of this system adopts C Plus Plus to write, the signal processing algorithm code write can be grafted directly in DSP hardware and run, and through engineering approaches degree is higher; Secondly, write just because of employing C Plus Plus, this simulation analysis software can the process of altitude simulation guidance header signal processor hardware execution algorithm and result, and convenient diagnosis target seeker hardware fault, is convenient to verify new algorithm simultaneously; Again, this software can be made into .exe file, takies resource and space is less, and total size is less than 10MB; Finally, this software bookbinding parameter is convenient, and objective interface is friendly, and travelling speed is faster.Same data and the result of needs, the execution time of this software is about 1/3 of the use MATLAB execution time.

Accompanying drawing explanation

Fig. 1 commonly uses target seeker data analysis flow process

Fig. 2 guidance header signal process simulation analysis system signal wiring relation

Fig. 3 guidance header signal process simulation analysis system

Fig. 4 simulation analysis software starts data processing

Fig. 5 signal processing algorithm flow process

Fig. 6 DDC process block diagram

Fig. 7 matched filter block diagram

Fig. 8 simulation analysis software pulse compression result shows

The horizontal false-alarm model of Fig. 9

Figure 10 simulation analysis software CFAR result shows

Embodiment

Now in conjunction with the embodiments, the invention will be further described for accompanying drawing:

The radar seeker that the present invention includes signal transacting and data processing algorithm and a set of self-editing simulation analysis software, radar signal data acquisition unit, computer for controlling and possess optical fiber communication forms, if Fig. 2 is its signal wiring graph of a relation, simulation analysis software can regard the software implementation to signal processor as, can the function such as execution algorithm and data processing of analogue signal processor.The method is when carrying out data processing to radar echo signal, utilize data acquisition equipment from the optical fiber interface high speed acquisition of guidance header signal processor being kept at number adopting equipment with road/difference road signal through down-converted, then by netting twine by adopted data importing on computer for controlling, use the simulation software of the method to carry out corresponding signal transacting and data processing afterwards, and reflect result with the form of data and chart.Therefore, carry out radar seeker data analysis and can rely on the simulation analysis softwares such as original MATLAB no longer merely, write owing to adopting C Plus Plus form, the signal transacting that this system software is self-editing and data processing code can be transplanted in target seeker digital signal processor (DSP) and perform, eliminate the process being become C language by MATLAB language conversion, shorten the time of DSP algorithm improvement and checking.

First, write the core of this system: simulation analysis software, function algorithm conventional for radar seeker is adopted in C Plus Plus and imbeds simulation analysis software, comprise software interface, file reading and the function such as preservation and signal processing algorithm, on software interface, develop corresponding datagraphic display window, if will verify that new Processing Algorithm can write corresponding code simultaneously.Secondly, in order to improve the speed of data acquisition, design and make the signal-processing board possessing Optical Fiber Transmission and replace the conventional signal-processing board by asynchronous serial port image data, here optical fiber advantage compared with asynchronous serial port is that fiber transmission speeds is high, Optical Fiber Transmission commonly uses 2.5Gbps transmission, and asynchronous serial port common speed is 230400bps or 115200bps, therefore Optical Fiber Transmission is more suitable for mass data transmission.Finally, a whole set of software and hardware system is coupled together, carry out the work such as target seeker data acquisition and simulation analysis.

Before data are processed, Usage data collection device is needed to gather the echo data of target seeker and be kept in data acquisition unit, and then this software is used to carry out loading and processing: first to open network and be connected, carry out TCP/IP with data acquisition unit to be connected, then file reading list, select to need file to be processed, select tupe and algorithm afterwards.Start on this basis to process, the process node according to being concerned about selects corresponding result to show, and meanwhile result is carried out record with the form of text.If certain the target process scheduling algorithm newly write obtains desirable effect in this software, so the C++ code of this algorithm can directly programming enter in target seeker DSP hardware, carry out corresponding target process test, further shorten new algorithm from exploitation to the time of engineer applied.

First, based on C Plus Plus, radar seeker data processing simulation analysis software is write based on MFC, if Fig. 3 is simulation analysis system, comprise target seeker, data acquisition unit, reading data module, mode of operation and parameter bookbinding module, signal processing module and result display and data storage module successively; Data acquisition unit gathers the echo data of target seeker, read data module to read echo data, mode of operation and parameter bookbinding module carry out mode of operation selection and setting parameter to echo signal processing, signal processing module carries out signal transacting to echoed signal, and echo signal processing result carries out showing and data preservation by result display and data storage module.Can select as required or fill in the information such as target seeker mode of operation, running parameter, and corresponding image and result can be shown as required in real time, also result can be preserved with the form of text and record, as Fig. 4.Secondly, guarantee that signal-processing board possesses light port communications ability, if do not need to redesign and increase this function.

Guidance header signal flow process is usually as follows: seeker antenna receiving target reflection echo, receive-transmit system is passed to through feeder line, after receive-transmit system downconverts to an intermediate frequency radar return, intermediate-frequency receiver again signal frequency conversion to two intermediate frequencies, then signal processor (DSP) is sent to, signal processor, through analog to digital conversion (ADC), carries out respective handling after now signal becomes digital signal and realizes the process such as target seeker Row control, Schema control, communication and control, Target Selection And Tracking.Digital signal is sent to data acquisition unit by light mouth after ADC, and be kept in collector, utilize netting twine that then the data reading stored is carried out Digital Down Convert (DDC), pulse compression, data rearrangement, moving target detect (MTD), the estimation of clutter center and horizontal false-alarm to detect (CFAR) etc., wherein the relevant treatment such as Target Selection And Tracking process can be carried out after CFAR, here writing and checking, as Fig. 5 of target classification and the relevant new algorithms such as tracking can be carried out as required.Concrete grammar is as described below:

Step one: Digital Down Convert (DDC) processes, and DDC process block diagram is as Fig. 6:

DDC first carries out A/D sampling to simulating signal x (t), forms Serial No. x (n) after digitizing, then with one group of orthogonal local oscillation sequence cos (w ₀n) with sin (w ₀n) be multiplied, then carry out filtering HFS by digital low-pass filtering (LPF), export in-phase component x _i(n) and quadrature component x _q(n).The software simulating based on C Plus Plus of this one-step algorithm can first produce one group of quadrature samples sequence and sampled echo carries out multiplication, processing signals bandwidth Design low-pass filter as required, filter coefficient is stored in this locality and carries out convolution algorithm as constant coefficient variable and orthorhombic phase multiplication result.If filter coefficient sequence is b (n), convolution algorithm is: in formula, x (n) is input signal sequence, and b (n) is filter coefficient, and y (n) is that filtering exports the function that just can realize DDC like this.

Step 2: coupling receives (pulse compression) process.Matched filter is exactly the optimum linear filter under maximum signal noise ratio principle, when the transition function of linear filter is the conjugate complex number of input signal spectrum, exportable maximum signal to noise ratio, so-called " coupling " refers to the transition function of matched filter and mating between signal spectrum, and the result of coupling makes output signal-to-noise ratio maximum.Suppose that input signal complex representation is x (n)=x _i(n)+j*x _qn (), matched filter complex representation is h (n)=h _i(n)+j*h _q(n), matched filter block diagram as shown in Figure 7:

Matched filter operation realizes following computing:

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

Wherein, n is current sampling point, and N is sample sequence length, and i is convolution iteration sequence number;

For chirp doppler radar seeker, matched filtering process is also process of pulse-compression.Fig. 8 provides process of pulse-compression and realizes result figure, selects option to select " pulse pressure-and ", this step process result of " pulse pressure-poor " i.e. Observable by drawing, and in figure, ordinate is echo quantification aftertreatment range value, and horizontal ordinate is sampling number.

Step 3: data rearrangement process.After coupling receives, data need carry out rearrangement process.The object of resetting carries out correlative accumulation to the same range unit echoed signal in different pulse repetition cycle, supposes that range unit is taken as 90, carries out rearrangement process to the signal in 128 pulse repetition cycles.During rearrangement, read/write address computing formula is: addr_w=m+n*128, and in formula, n is sampling number, and span is 0 ~ 89; M is repetition periodicity, and span is 0 ~ 127.Then 90 sampled points first writing first pulse according to pulse repetition time number during write operation write the number of second pulse repetition time, write successively.I.e. first pulse repetition time write address: m=0, n=0 ~ 89, then writes m=1; N=0 ~ 89.During read operation, first read the number of the different pulse repetition times of first sampled point, then read the number of second sampled point different pulse repetition time, read successively.Namely first sampling reading address is n=0, m=0 ~ 127; Second sampling reading address is: n=1, m=0 ~ 127.Until all data readings are complete.Programming realization needs to follow write-then-read processing sequence when resetting process to carry out.

Step 4: data carry out resetting laggard action object detection process (MTD).For pulse Doppler radar signal, in the echo in the different repetition cycle, modulation has target and target seeker relative velocity, by carrying out FFT computing, can distinguish sound target.The echo in different repetition cycle is reset by range unit, then carries out FFT computing, that is:

$Y^{\′}\left(k\right)=\underset{n=1}{\overset{M}{\Σ}}{y}^{\′}\left(n\right)e^{-j\frac{2\mathrm{\π}}{N}}\left(n-1\right)\left(k-1\right)---\left(2\right)$

In formula, y ' (n) is input signal, and M is that FFT counts, and k is current sequence number, and span is 0 ~ M-1, Y ' (k) is sequence after Current Transform; Operation result is stored in variable.

Step 5: the result of MTD is carried out asking modular arithmetic, the data chosen in the distance range of target place are averaged by Doppler's passage, and Doppler's channel number that maximizing is corresponding in the result of averaging, this channel number illustrates clutter center.The Doppler channel number corresponding according to clutter center carries out dynamic and static target differentiation.Clutter unit channel is as static target, and other passages are moving-target.

Step 6: the modulus value that step 5 is obtained is used for carrying out CFAR detection process (CFAR) and obtains multiple target.Here CA-CFAR model and implementation is adopted, as Fig. 9.In Fig. 9, G is protected location length, and L is the length of left and right window.Calculate element amplitude average in the window of left and right during algorithm realization, be multiplied by CFAR factor T, then compare with unit to be detected, if unit to be detected is large, and higher than system noise amplitude, then think by detection algorithm, namely this detecting unit is target.Figure 10 is the result figure of Echo Processing.

Step 7: calculate Capture condition according to bookbinding target information, amplitude of finding in multiple target after by CFAR detection maximum as the target needing to follow the tracks of, meet target that in the target range scope of setting, velocity range, angle error, selection signal to noise ratio (S/N ratio) is maximum at the same time as tracking target.Target information is stored in local file, this result can be used for and real system working result compares simultaneously.

Step 8: carry out the renewal of tracking target prior imformation, as target choice condition in result next time; Namely step 5, six, seven is repeated, until all data have been processed.

Claims (3)

1. a radar seeker simulation of Signal Processing analytical approach, is characterized in that step is as follows:

Step 1: seeker antenna receiving target reflection echo, downconverts to an intermediate-freuqncy signal by radar return, an intermediate-freuqncy signal is converted to two intermediate-freuqncy signals again, two intermediate-freuqncy signals being carried out digital-to-analog conversion is digital signal;

Step 2: by digital signal and one group of orthogonal local oscillation sequence cos (w ₀n) with sin (w ₀n) be multiplied, then by digital low-pass filtering LPF filtering HFS, export in-phase component x _i(n) and quadrature component x _q(n);

Step 3: by input signal x (n)=x _i(n)+j*x _q(n) and matched filter h (n)=h _i(n)+j*h _qn () is carried out convolution and is obtained process of pulse-compression signal:

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

Wherein, n is current sampling point, and N is sample sequence length, and i is convolution iteration sequence number;

Step 4: paired pulses compression processing signals is carried out rearrangement and obtained y ' (n), and the method for described rearrangement is that the echo in different repetition cycle is reset by range unit;

Step 5: FFT computing is carried out to the y ' (n) reset:

$Y^{\′}\left(k\right)=\underset{n=1}{\overset{M}{\Σ}}{y}^{\′}\left(n\right)e^{-j\frac{2\mathrm{\π}}{N}}\left(n-1\right)\left(k-1\right)$

Wherein, y ' (n) is input signal, and M is that FFT counts, and k is current sequence number, and span is 0 ~ M-1, Y ' (k) is sequence after Current Transform;

Step 6: modular arithmetic is asked to Y ' (k), CFAR detection process CFAR is carried out to the modulus value of Y ' (k) and obtains multiple target, meet the target range scope of setting, velocity range, selection signal to noise ratio (S/N ratio) is maximum in angle error target at the same time as tracking target.

2. a kind of radar seeker simulation of Signal Processing analytical approach according to claim 1, it is characterized in that step 6 replaces with and modular arithmetic is asked to Y ' (k), average by Doppler's passage to the modulus value within the scope of the target range of satisfied setting, the Doppler's channel number finding Largest Mean corresponding is clutter center.

3. realize a radar seeker simulation of Signal Processing analytic system for method according to claim 1, it is characterized in that comprising the bookbinding of target seeker, data acquisition unit, reading data module, mode of operation and parameter module, signal processing module and the result that connect successively shows and data storage module; Data acquisition unit gathers the echo data of target seeker, read data module to read echo data, mode of operation and parameter bookbinding module carry out mode of operation selection and setting parameter to echo signal processing, signal processing module carries out signal transacting to echoed signal, and echo signal processing result carries out showing and data preservation by result display and data storage module.