CN105242274A - Ionosphere non-coherent scatter radar differential phase detection method - Google Patents
Ionosphere non-coherent scatter radar differential phase detection method Download PDFInfo
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- CN105242274A CN105242274A CN201510700313.2A CN201510700313A CN105242274A CN 105242274 A CN105242274 A CN 105242274A CN 201510700313 A CN201510700313 A CN 201510700313A CN 105242274 A CN105242274 A CN 105242274A
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Abstract
The invention provides an ionosphere non-coherent scatter radar differential phase detection method, comprising steps of 1 computer simulation and modeling research, 2 non-coherent scatter software radar verification test, 3 non-coherent scatter radar verification test, and 4 optimization and improvement of the radar echo numerical module, the parameter extraction algorithm and the test method according to the computer simulation and practical detection result. The invention can simultaneously and fast obtain the parameters of the high accuracy electronic density of the whole ionosphere height, the electronic temperature, the ion temperature, the plasma drift speed in the direction perpendicular to the magnetic line, etc.
Description
Technical field
The present invention relates to a kind of incoherent scattering radar differential phase detection method, be applicable to the incoherent scattering sounding of ionosphere incoherent scattering radar to space plasma target in compared with low signal-to-noise ratio situation.
Background technology
Incoherent scattering sounding refers to that electromagnetic wave causes scattering owing to being subject to the random thermal fluctuation impact of quasi-equilibrium electron density in ionosphere, receives this energy thus the ionospheric probing method of acquisition Ionospheric physics parameter.Traditional ISR detection method is power spectrum or the autocorrelation function of analyzing tested heating region non-coherent scattering echo, by returning the Ionospheric Parameters of drilling and drawing tested heating region.Although ISR is the most effective equipment measuring Ionospheric Parameters, high construction and operating cost limit its widespread use.And traditional ISR Detection Techniques to echo signal to noise ratio (S/N ratio) require higher, need huge emissive power and longer integration time during detection, but under low signal-to-noise ratio environment (as night) still extract less than actual parameter; And existing ISR Detection Techniques can only detect limited Ionospheric Parameters and region under single detective pattern, generally need switch different detection modes to detect different Ionospheric Parameters and region, detection efficiency is not high.Therefore existing ISR Detection Techniques are in the time or spatially usually can not obtain Ionospheric Parameters to continuous effective, ionospheric many phenomenons all cannot be observed, and the research of space physics needs the continuous coverage of Ionospheric Parameters.To the monitoring and forecast of space environment in the urgent need to new detection method, to strengthen incoherent scattering radar high precision quick detection ability to Ionospheric Parameters under Low SNR, alleviate its dependence to detection condition, detection time and emissive power, meet the needs of PROGRESS OF IONOSPHERIC RESEARCH IN.
The ultimate principle of incoherent scattering radar differential phase detection technology is: when incoherent scattering radar is perpendicular to magnetic line of force orientation detection, and electromagnetic backscattering enhanced comprises ordinary and extraordinary two kinds and has the composition that out of phase postpones.If with pair of orthogonal linear polarized antenna battle array detection back scattering wave field, the information such as tested region ionospheric electron density, electronic and ionic temperature ratio will be comprised in the average power of the echo that two kinds of different polarized antenna arrays export, phase differential and cross-correlation (Cross-CorrelationFunction, CCF) data.Corresponding incoherent scattering radar echo values model is set up based on electromagnetic wave propagation effect, non-coherent scattering theory, antenna theory, soft object radar equation etc. in magneto-ionic medium.With corresponding fitting algorithm, matching is carried out to measured data and model data, can therefrom extract electron density and electronic and ionic temperature compares parameter.Now Echo Doppler Spectra is very narrow, can extract Plasma drift velocity from Doppler shift.Be aided with multiple-pulse detection and can extract the information such as electron temperature from echo power spectrum.This technology has that detection accuracy is high, speed of detection is fast, signal to noise ratio (S/N ratio) requires the plurality of advantages such as low, can simultaneously the high-precision ionospheric electron density of quick obtaining, electron temperature, ion temperature, perpendicular to parameters such as magnetic line of force direction Plasma drift velocities.
Summary of the invention
The technology and method of horn of plenty and the detection of development ionosphere incoherent scattering radar, meet the monitoring and forecast of PROGRESS OF IONOSPHERIC RESEARCH IN and space environment in the urgent need to, the invention provides a kind of ionosphere incoherent scattering radar differential phase detection method.The present invention can be applicable to the incoherent scattering sounding of space plasma target under Low SNR, has both met the demand of current subject study, meet simultaneously the monitoring and forecast of PROGRESS OF IONOSPHERIC RESEARCH IN and space environment in the urgent need to.
The present invention is based on the motion state of emulation different band charged particle in magnetization plasma, and consider that it interacts and constellation effect, build scattering spectra model; Scattering spectra modeling when detecting perpendicular to the magnetic line of force takes into full account Coulomb collision effect, adopts suitable model or method, emulation ion scattering spectrum and electron scattering spectrum; The scattering spectra of the different ions such as emulation oxygen, hydrogen, helium, model should consider the comprehensive effect of different ions composition.Use the theoretical propagation effect of electromagnetic wave in ionosphere to incoherent scattering radar transmitting and receiving of Appleton-Hartree to analyze, and take into full account anisotropic ionosphere magnetopasma characteristic; Research electromagnetic wave in magneto-ionic medium propagation effect for the impact of radar antenna battle array antenna pattern.Ambiguity function theory is utilized to carry out wave form analysis research.Set up contacting and corresponding index between ambiguity function to target optimal detection waveform.Invent difference phase scheme detection waveform the most suitable, best and parameter thereof for different space plasmas detection demand, thus solve the problem to space plasma target in compared with low signal-to-noise ratio situation.
Concrete steps of the present invention are as follows:
1. Computer Simulation and Modeling Research:
(1) utilize ambiguity function theory to carry out radar waveform analysis, for different space plasmas detection demand, obtain detection waveform the most suitable;
(2) utilize Fokker-Planck model emulation ion scattering spectrum, obtain suitable electron scattering spectrum emulation mode and the simulated scatter spectrum of different ions;
(3) use the theoretical propagation effect of electromagnetic wave in ionosphere to incoherent scattering radar transmitting and receiving of Appleton-Hartree to analyze, and exploitation obtain corresponding computer program emulates;
2. non-coherent scattering Software Radar validation test:
(1) use soft object radar equation to incoherent scattering radar echo values model modeling, to obtain under different detection range the echo power section model of the echo signal power that polarization reception passage in the same way exports, and obtain the echo differential phase section model of cross correlation function of orthogonal polarization receiving cable output signal under different detection range;
(2) iterative algorithms such as least square method are used, obtain the physical parameter of tested heating region, draw accurately perpendicular to magnetic line of force direction Plasma drift velocity by the doppler spectral calculating echoed signal, from echo power spectrum, extract the information such as electron temperature;
3. incoherent scattering radar validation test: use radar equipment to obtain data, extract Ionospheric Parameters; And the result of detection of plurality of devices is contrasted, to verify its correctness;
4. according to Computer Simulation and actual detection result, Optimal improvements radar return numerical model, parameter extraction algorithm and experimental technique.
Whether normally to verify waveform and the work of whole radar system each several part by closed-loop experiment, adjustment waveform parameter improves Waveform Design, calibration radar system partial parameters, thus provides echoed signal relevant peaks.
Verified detecting function and the technical indicator of Detection Techniques and echo processing techniques by open loop experiment, thus result of detection is analyzed, propose improvement project, further Improvement and perfection Detection Techniques and echo processing techniques.
Compare existing incoherent scattering radar detection method, ionosphere of the present invention incoherent scattering radar differential phase detection method can simultaneously the high-precision electronic density of the whole layer height of quick obtaining, electron temperature, ion temperature, perpendicular to parameters such as magnetic line of force direction Plasma drift velocities.This invention technology has the plurality of advantages such as detection accuracy is high, speed of detection fast, signal to noise ratio (S/N ratio) requirement is low, is applicable to the incoherent scattering sounding of space plasma target.This invention technology enhances incoherent scattering radar high precision quick detection ability for Ionospheric Parameters under Low SNR, and reduce its operating cost to a certain extent, enrich and developed the technology and method of ionosphere incoherent scattering radar detection, meet the monitoring and forecast of PROGRESS OF IONOSPHERIC RESEARCH IN and space environment in the urgent need to, possess important scientific value and Practical significance.
Accompanying drawing explanation
Fig. 1 is process flow diagram of the present invention.
Fig. 2 is detection system closed-loop experiment schematic diagram of the present invention.
Embodiment
Embodiment 1
As shown in Figure 1, ionosphere incoherent scattering radar differential phase detection method, concrete steps are as follows:
1. Computer Simulation and Modeling Research:
(1) utilize ambiguity function theory to carry out radar waveform analysis, and utilize its fuzzy graph of the corresponding computer program emulation of the software developments such as matlab.For different space plasmas detection demand, find detection waveform the most suitable.
(2) based on the motion state of different band charged particle in magnetization plasma, and consider that it interacts and constellation effect, non-coherent scattering spectrum is emulated; Scattering spectra when detecting perpendicular to the magnetic line of force should take into full account Coulomb collision effect, can utilize Fokker-Planck model emulation ion scattering spectrum, with suitable method artificial electronic scattering spectra; The scattering spectra of the different ions such as emulation oxygen, hydrogen, helium, model should consider the comprehensive effect of different ions composition.
(3) use the theoretical propagation effect of electromagnetic wave in ionosphere to incoherent scattering radar transmitting and receiving of Appleton-Hartree to analyze, and take into full account anisotropic ionosphere magnetopasma characteristic; Research electromagnetic wave in magneto-ionic medium propagation effect for the impact of radar antenna battle array antenna pattern; And develop corresponding computer program and emulate.
2. non-coherent scattering Software Radar validation test:
(1). use soft object radar equation to incoherent scattering radar echo values model modeling, to emulate under different detection range the echo signal power that polarization reception passage in the same way exports, obtain echo power section model; Emulate the cross correlation function of orthogonal polarization receiving cable output signal under different detection range, therefrom extract phase of echo difference information, obtain echo differential phase section model.The impact of the factor such as accurate Calculation radio wave propagation, antenna polarization, scattering spectra, RCS, detection waveform, system attenuation, filter for receiver coefficient is answered in modeling.
(2). by iterative algorithms such as least square methods, by from radar in the same way with cross-polarized antennas battle array the data such as actual echo average power, phase differential and cross-correlation recorded and model data carry out matching, obtain the physical parameter such as the accurate electron density of tested heating region, electronic and ionic temperature ratio.Can be drawn accurately perpendicular to magnetic line of force direction Plasma drift velocity by the doppler spectral calculating echoed signal.The information such as electron temperature are extracted from echo power spectrum.
3. incoherent scattering radar validation test: the non-coherent scattering Software Radar utilizing our unit developing, great instrument special project supports the lower equipment such as Sanya incoherent scattering radar under preparation and Jicamarca incoherent scattering radar, obtain data, extract Ionospheric Parameters.And the result of detection of plurality of devices is contrasted, to verify its correctness
4. according to Computer Simulation and actual detection result, Optimal improvements radar return numerical model, parameter extraction algorithm and experimental technique.
(1). the detection system closed test schematic diagram according to Fig. 2 carries out closed-loop experiment:
Method: inside connect signal source, internal system signal flow operates.Transmitter output signal is input to receiver by cable, attenuator closed loop.
Object: normally whether, adjustment waveform parameter improves Waveform Design for checking waveform and the work of whole radar system each several part, calibration radar system partial parameters.
Target: provide echoed signal relevant peaks.
(2). open loop experiment:
Method: by incoherent scattering radar perpendicular to magnetic line of force orientation detection, receives backscatter signal by pair of orthogonal linear polarized antenna battle array.The never average power of echo, phase differential and the cross-correlation extracting data tested region Ionospheric Parameters that export of same polarization aerial array.
Object: the detecting function of checking Detection Techniques and echo processing techniques and technical indicator.
Target: analyze result of detection, proposes improvement project, further Improvement and perfection Detection Techniques and echo processing techniques.
Claims (5)
1. ionosphere incoherent scattering radar differential phase detection method, is characterized in that concrete steps are as follows:
1. Computer Simulation and Modeling Research:
(1) utilize ambiguity function theory to carry out radar waveform analysis, for different space plasmas detection demand, obtain detection waveform the most suitable;
(2) utilize Fokker-Planck model emulation ion scattering spectrum, obtain suitable electron scattering spectrum emulation mode and the simulated scatter spectrum of different ions;
(3) use the theoretical propagation effect of electromagnetic wave in ionosphere to incoherent scattering radar transmitting and receiving of Appleton-Hartree to analyze, and exploitation obtain corresponding computer program emulates;
2. non-coherent scattering Software Radar validation test:
(1) use soft object radar equation to incoherent scattering radar echo values model modeling, to obtain under different detection range the echo power section model of the echo signal power that polarization reception passage in the same way exports, and obtain the echo differential phase section model of cross correlation function of orthogonal polarization receiving cable output signal under different detection range;
(2) iterative algorithms such as least square method are used, obtain the physical parameter of tested heating region, draw accurately perpendicular to magnetic line of force direction Plasma drift velocity by the doppler spectral calculating echoed signal, from echo power spectrum, extract the information such as electron temperature;
3. incoherent scattering radar validation test: use radar equipment to obtain data, extract Ionospheric Parameters; And the result of detection of plurality of devices is contrasted, to verify its correctness;
4. according to Computer Simulation and actual detection result, Optimal improvements radar return numerical model, parameter extraction algorithm and experimental technique.
2. ionosphere according to claim 1 incoherent scattering radar differential phase detection method, it is characterized in that: in step 4, by closed-loop experiment checking waveform and the work of whole radar system each several part whether normal, adjustment waveform parameter improves Waveform Design, calibration radar system partial parameters, thus provide echoed signal relevant peaks.
3. ionosphere according to claim 1 incoherent scattering radar differential phase detection method, it is characterized in that: in step 4, detecting function and the technical indicator of Detection Techniques and echo processing techniques is verified by open loop experiment, thus result of detection is analyzed, improvement project is proposed, further Improvement and perfection Detection Techniques and echo processing techniques.
4. ionosphere according to claim 2 incoherent scattering radar differential phase detection method, it is characterized in that: closed-loop experiment method is: inside connect signal source, internal system signal flow operates, and transmitter output signal is input to receiver by cable, attenuator closed loop.
5. ionosphere according to claim 3 incoherent scattering radar differential phase detection method, it is characterized in that: open loop experiment method is: by incoherent scattering radar perpendicular to magnetic line of force orientation detection, backscatter signal is received, never the average power of echo, phase differential and the cross-correlation extracting data tested region Ionospheric Parameters that export of same polarization aerial array by pair of orthogonal linear polarized antenna battle array.
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| CN108254730A (en) * | 2018-04-11 | 2018-07-06 | 西安电子科技大学 | Auto-correlation function processing method at radar zero time delay based on damping fitting |
| CN110927687A (en) * | 2019-11-09 | 2020-03-27 | 中国电波传播研究所（中国电子科技集团公司第二十二研究所） | Meteor detection method based on incoherent scattering radar |
| CN111580061A (en) * | 2020-05-20 | 2020-08-25 | 中国科学院地质与地球物理研究所 | Ionized layer electron density inversion method based on CLEAN algorithm |
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