51 results about "Incoherent scatter" patented technology

The invention discloses a multi-source data fusion-based three-dimensional ionosphere chromatographic method, utilizes GNSS observation data, occultation observation data on low orbit satellites, Jason-1 and Jason-2 seasat altimetry data and ionosphere altimeter data for the first time, and develops research on ionosphere electron density tomography. An inversion result is compared with observation data of an incoherent scattering radar, and a result verifies effectiveness and reliability of the three-dimensional ionosphere chromatographic method provided by the invention in fusing multi-source data to perform inversion of ionosphere electron density and superiority of the method to use of GPS observation data alone to perform inversion.

The invention discloses a detection method for the electron density of an ionization layer based on radar echoes. The method is realized by the following steps that (1) original data is collected and stored; (2) non-coherent scattering echoes are extracted from the ionization layer; and (3) the electron density of the ionization layer is calculated. The disclosed detection method has great significance in radar wave environment adaptation and space environment monitoring and early-warning domestically; and compared with a present special-purposed electron density detection method for the ionization layer, the method of the invention is simple and economic. The method of the invention is also high in compatibility and transplantability, and is suitable for most space monitoring radars, and the radars need only to provide signal interfaces of original echo signals, emission pulse signals, main pulse signals and sampling clock and the like.

A method and system whereby a narrow linewidth coherent laser source when transmitted as a plurality of output signals and subsequently detected at a distance appears to produce the uniform illumination characteristics of an incoherent source thereby suppressing laser speckle and environmentally induced scintillation effects. A master oscillator source is split into N signals, each of which is independently phase modulated by frequencies designed to minimize a derived apparent incoherence factor. The signals are then either directed to an object to be illuminated so that they overlap at the object or first recombined and directed to the object.

The invention provides an ionized layer incoherent scattering radar simulation system, which is characterized in that a modular design idea is adopted, the system is divided into a signal simulation module, an incoherent scattering spectrum simulation module, an ionized layer parameter analysis module, a radar power simulation module and an antenna array simulation module according to a radar actual system structure and functions of each extension set, module functions are basically the same as completing functions of each system extension set, transmission and sharing of data and information among the modules can be realized, and dynamic demonstration is carried out by using an MATLAB graphical user interface function. The ionized layer incoherent scattering radar simulation system well solves a problem that the incoherent scattering radar is small in number of research platform and difficult in test, and can help the technicists to improve abilities of analyzing and solving problems and an ability of carrying out radar equipment technical research.

The invention discloses a phased-array incoherent scattering radar system. An excitation source signal is generated through a digital receiver and is sent to N transmit-receive switches through a power divider to be pre-amplified, the output, with certain power magnitude, of each transmit-receive switch is fed back to each set of N transmit-receive assemblies through the power divider, the N transmit-receive switches drive the N*N transmit-receive assemblies to work at the same time to carry out final stage amplification on an emitting signal, the N*N transmit-receive assemblies feed the final output power back to N*N antenna sub-arrays, each antenna sub-array is internally provided with an antenna unit, all antenna units are driven through the power divider and send incident waves, the incident waves are scattered towards different directions through atmospheric plasma, the antenna units feed inducted echo signals to a reception channel, the inducted echo signals are amplified through the transmit-receive assemblies and are synthesized again through the synthesized function of a feeder system, and one loop of echo signals are formed at last and input to the digital receiver in sequence to be processed through a signal processing device. At last, the echo signals are output to a master control computer to enable the master control computer to process and synthesize products.

The invention discloses a meteor detection method based on an incoherent scattering radar, and the method comprises the following steps: (1), dividing original baseband orthogonal two-path sampling data into two parts, enabling one part of the data to serve as the input data of meteor head event detection, enabling the other part of the data to serve as the input data of meteor trail event detection, and enabling the two parts of event detection to operate in parallel as independent steps; (2) carrying out meteor event detection; and (3) carrying out meteor parameter extraction. According to the meteor detection method based on the incoherent scattering radar, the sensitivity to a radar beam arrival angle is overcome, the coverage range of a detectable meteor area is widened, meteor eventscan be detected in real time, and meteor parameters such as the height, the radial speed, the radial deceleration and the equivalent scattering sectional area are extracted.

The invention provides a high-sensitivity multifunctional incoherent scattering radar system based on a digital antenna array, which comprises an antenna array and a back-end processing controller, wherein the back-end processing controller is used to generate a transmission instruction according to a preset transmission parameter; the antenna array is used to generate a transmission signal according to the transmission instruction, transmit the transmission signal, receive a space electromagnetic wave signal and perform first signal processing on the space electromagnetic wave signal; and theback-end processing controller is further used to perform second signal processing on the space electromagnetic wave signal through signal processing according to a preset working mode, and the working mode includes a space target tracking mode or an ionosphere detection mode. The system provided in the invention is low in noise and high in sensitivity during a radar detection process.

According to the invention, research and analysis are carried out on a plasma scattering spectrum without considering collision, a collision plasma scattering spectrum without considering the magnetic field and an incoherent scattering power spectrum under different ion component percentages respectively based on fundamental principles of an incoherent scattering theory, and an ionized layer incoherent scattering radar incoherent scattering spectrum modeling method is provided. Besides the ability of simulating the three types of fundamental scattering spectra, the method provided by the invention can also simulate differently encoded scattering spectra and scattering spectra with different heights. Analysis is carried out on an echo simulation result of radar signals, and parameters extracted by a simplified algorithm are consistent with IRI.

The invention discloses an ISR (incoherent scatter radar) signal processing system based on alternate code modulation, and the system is mainly used for solving the problems that the traditional radar signal processing system cannot process an ionospheric scattering signal with large echo data amount and low signal-to-noise ratio and taking a soft target as the target. The system mainly comprises a DSP (Digital Signal Processor) module and an FPGA (Field Programmable Gate Array) module and a power supply module, wherein regarding alternate code modulation, the DSP module is mainly used for completing signal filtration, autocorrelation function calculation, autocorrelation accumulation and signal power spectrum calculation to obtain an autocorrelation function and a power spectrum evaluation result of an ionospheric plasma; the FPGA module is used for receiving and transmitting processing parameters and signal data, and performing digital down converter on the signal data; and the power supply module is used for supplying required work voltages for the FPGA module and the DSP module. The system has the advantages of high stability, high processing speed, strong data throughout and easiness for hardware implementation, can be used in the ISR signal processors, and performs ionospheric detection and parameter evaluation.

The invention belongs to the technical field of ionosphere detection, particularly relates to an ionosphere detection system based on a magnetized plasma incoherent scattering theory spectrum, and aims to solve the problem in the prior art that the ionosphere state cannot be accurately detected under different conditions. The system comprises an input module which acquires an ionosphere initial incoherent scattering theoretical spectrum; a model selection instruction module which generates a model selection instruction; an incoherent scattering theory spectrum module which pre-constructs an incoherent scattering theory spectrum model, performs model solving under different conditions to obtain each incoherent scattering theory spectrum sub-model, and obtains an ionosphere radar echo powerspectrum through the corresponding sub-model based on the ionosphere initial incoherent scattering theory spectrum and the model selection instruction; and an output module which extracts ionosphere state, motion, structure and disturbance information based on the ionosphere radar echo power spectrum and outputs the information. Different ionosphere conditions correspond to different sub-models, and the ionosphere information under different conditions can be accurately and quickly detected.

The invention belongs to the technical field of fiber lasers, and particularly relates to an incoherent super-continuum spectrum light source with controllable spectrum and tunable output power. The incoherent super-continuum spectrum light source comprises a random pulse fiber laser, a single-mode fiber, a double-clad ytterbium-doped/tapered ytterbium-doped fiber amplifier and a highly-nonlinearintermediate infrared soft glass fiber. The incoherent super-continuum spectrum light source can realize three modes of incoherent super-continuum spectrum output such as a near-infrared band or an intermediate infrared band, a visible light-near infrared band or a near infrared-intermediate infrared band and a visible light-intermediate infrared band through selecting different super-continuum generation modules. In addition, through performing combined control on the length of the single-mode fiber, the output power of a pumping source in the double-clad ytterbium-doped/tapered ytterbium-doped fiber amplifier and the length of the highly-nonlinear intermediate infrared soft glass fiber, the incoherent super-continuum spectrum light source not only can realize control on the output spectrum range and shape, but also can realize tunable output power of the super-continuum spectrum under the condition that the output spectrum range and shape are fixed.

The invention belongs to the field of signal and information processing, particularly relates to a signal processing method, system and device based on a phased array incoherent scattering radar, andaims to solve the problems of low real-time performance and accuracy of signal processing of the existing incoherent scattering radar. The method comprises the following steps: acquiring an echo signal scattered by an ionized layer to aquire an IQ digital signal as a first signal through down-conversion, AD sampling and digital orthogonal down-conversion; performing complex weighting and summationoperation on the first signal to obtain a second signal; removing clutters of the second signal through a preset clutter removing method, and obtaining autocorrelation data through a frequency domainFFT algorithm; circularly acquiring autocorrelation data, accumulating the autocorrelation data, removing background noise after accumulation, and performing calibration correction through a preset data calibration method and a spectrum ambiguity function; and fitting the calibrated and corrected data with theoretical autocorrelation data to obtain ionospheric parameters. According to the invention, the real-time performance and the accuracy of signal processing of the incoherent scattering radar are improved.

The invention discloses a method of inverting strongly-disturbed ionospheric parameters by using a plasma line cascade structure. The method comprises steps: (1) an incoherent scattering radar is used for observing data, an abnormal incoherent scattering plasma line power spectrum with a cascade structure for a strongly-disturbed area caused by an ionospheric heating experiment is extracted; (2) a correlated peak frequency difference in the abnormal incoherent scattering plasma line power spectrum with a cascade structure is counted; (3) a low-frequency wave frequency appearing in the ionospheric heating process is determined; (4) the counted frequency difference in the second step and the low-frequency wave frequency calculated in the third step are compared to determine which low-frequency wave in instable parametric decay in the case of ionospheric heating generates the cascade structure; and (5) according to the result in the fourth step, the electron density and the electron temperature are acquired according to an fpi calculation formula. The method can improve the inversion precision to a large degree, and is a new method of acquiring the strongly-disturbed ionospheric parameters.

The invention belongs to the technical field of spaceflight measurement and control, and particularly relates to an atmospheric refraction error correction method for an aviation star sensor. The method comprises the following steps of: performing series expansion on an atmospheric refraction integral formula according to a secant function to obtain an initial form of series expansion, screening series expansion terms according to a correction precision requirement and obtaining an atmospheric refraction correction model; according to the mass spectrometer and incoherent scattering radar, acquiring atmospheric parameter data of which the altitude is greater than 6000 meters; analyzing monthly average atmospheric parameter data hour by hour according to the NCEP, obtaining atmospheric parameter data with altitude below 6000 meters, and establishing an atmospheric parameter empirical model according to the obtained atmospheric parameter data and atmospheric parameter data; according to the input parameters obtained in real time, conducting combined processing on the atmospheric refraction correction model and the atmospheric parameter empirical model, correcting atmospheric refraction errors, and obtaining corrected atmospheric refraction errors.

The invention discloses a method for calculating a scattering statistical moment of a two-dimensional random rough surface. The method specifically comprises the following steps: utilizing a Beckmanntheory and a Gaussian moment theorem; through strict theoretical derivation, giving a calculation formula of a second moment of a scattering field, coherent and incoherent scattering intensity and a fourth moment of the scattering field. Therefore, the scattering field high-order moment can be degraded to the low-order moment. The correctness of the scattering field four-order moment function is verified. The laser intensity detection quality can be analyzed through the random rough surface scattering four-order moment function. The method can be widely applied to research of rough surface speckle detection problems in national defense and civil fields.

The invention discloses an abnormal incoherent scattering ion line spectrum strong disturbance ionosphere parameter inversion method based on a three-peak structure having a zero frequency peak. The method comprises steps that by adopting incoherent scattering radar observation data, an abnormal incoherent scattering ion line spectrum having a zero frequency peak three-peak structure in a strong disturbance area caused by an ionosphere heating experiment is extracted; a conventional equilibrium state incoherent scattering theory is corrected by adopting Super-Gaussian distribution or Bump-on-tail distribution of heating electrons, and inversion of a three-peak abnormal spectrum is carried out according to the corrected incoherent scattering theory; the correction and the inversion of the extracted abnormal spectrum are carried out, and an inversion result is compared with an uncorrected inversion result, and a better inversion result is used a final inversion result. By aiming at the conventional inversion method only considering correction of a limitation of equilibrium state Maxwell distribution, great errors caused by the conventional inversion process is remedied, and more reasonable estimation of strong disturbance ionosphere parameters is realized.

The invention discloses large-size object laser radar imaging technology simulation. The technical scheme provided by the invention comprises steps of firstly constructing a total scattering power equation of a laser radar, wherein the equation is that Ps(t) = Pc(t) + Pf(t), Ps(t) represents the total scattering power, Pc(t) represents the coherent scattering power, and Pf(t) represents the non-coherent scattering power; and performing laser one-dimensional range profile simulation on a spherical object or a tapered object. The beneficial effects of the technology simulation are that beneficial technology supplements and effective technology supports are provided for experiment tests or laser radar engineering applications through the large-size object laser radar imaging technology simulation.

The invention discloses a simulink-based non-coherent scattering radar echo simulation method and a system. The method comprises the following steps of simulating and emitting a radar pulse signal by a radar pulse emitter in simulink, amplifying the power of the radar pulse signal by a transmitter, increasing the gain of the radar pulse signal by a transmitting antenna, scattering the radar pulse signal by a target simulation ionized layer to form an echo signal, filtering the signal by a receiver analog front end, processing the signal by a receiver digital processing module, outputting a related signal of the echo signal by an output module, and importing the simulated echo signal into the MATLAB for further treatment. According to the invention, the process of sending the radar pulse signal and scattering the outputted radar pulse signal by the ionized layer to form the echo signal can be simulated. Therefore, the scientific research personnel can be helped to get rid of limitation of radar equipment conditions. No expensive radar equipment is required to acquire related radar echo data. Therefore, radar echoes scattered by the ionized layer can be simulated conveniently and flexibly.

The invention is a combiner and a method for selectively combining modulated signals. The combiner includes a first modulator (12) with a selective input which receives at least one input signal and a first carrier signal and which outputs a first output modulated with the first carrier signal; a second modulator (14) with a selective input which receives at least one input signal and a second carrier signal and which outputs a second output modulated with the second carrier signal; means for combining (24′) the first and second amplified output signals to provide a combined output; and wherein the first and second carrier signals are selectably coherent or incoherent with the selection of first and second coherent carrier signals causing the combined output to comprise a single carrier of higher power and the selection of incoherent carrier signals causing the combined output to comprise two distinguishable carriers of lower power.

The invention discloses a small-size space debris detection and parameter extraction method based on incoherent scattering radar. The method comprises the following steps of (1), carrying out space debris target detection based on large step size and small step size combined traversal search radar echo data; (2), carrying out repaid coherent integration; and (3), carrying out space debris orbit parameter c based on Bayesian regression. Compared with an existing radar target detection algorithm, the method disclosed by the invention has the advantages that integration losses of phase-coded signals resulting from Doppler sensibility can be effectively overcome. The coherent integration can be finished with operation quantity lower than that of a conventional MTD algorithm. Through combination of technologies such as parallel computing and GPU acceleration, real-time space debris target detection and parameter extraction can be finished.

The invention discloses a blue-green hollow monox photonic crystal structural color film and a preparing method thereof, and belongs to the technical field of preparation of photonic crystal structural color films. According to the preparing method, organic microsphere polystyrene (PS) is used as a template, the surface of PS is modified with -NH2, the surface of PS is coated with a uniform monox layer through a modified Stober method, finally, a photonic crystal structure of an opal structure is formed on the surface of a glass substrate through self-assembly, and then PS microspheres are carbonized through calcining under protection of reducing atmosphere. As a black substance generated by the carbonized microspheres exists in all hollow monox shells, most incoherent scattered light is absorbed to obtain the blue-green hollow monox photonic crystal structural color film assembled by monox hollow spheres with high saturability. The method is simple in process, the raw materials are easy to obtain, and the blue-green hollow monox photonic crystal structural color film will be widely applied to display, printing, paint, cosmetics, photonic crystals and other aspects.