104 results about "X-ray pulsar" patented technology

The invention discloses an X-ray pulsar navigation embedded simulation system based on a semiconductor laser, which comprises a data simulation unit, a photon emission unit, a photon detection unit and a navigation test unit. The data simulation unit simulates X-ray pulsar radiation signal data, and sends the X-ray pulsar radiation signal data to the photon emission unit; the photon emission unit uses simulation data to modulate light intensity of a laser modulation laser, and radiate lasers to the atmosphere; the photon detection unit receives the lasers of the photon emission unit from the atmosphere, filters non-laser spectra components in background sunlight, and sends the received lasers to the navigation test unit after carrying out counting on the received lasers; and the navigation test unit carries out noise elimination, pulse profile accumulation, pulse arrival time measurement treatment on the data of the photon detection unit, and utilizes time measurement data to carry out a navigation test. The invention can provide a complete simulation experiment platform for obtaining navigation signals, signal processing, time synchronization and navigation design verification of navigation signals.

The invention relates to an X-ray pulsar navigation ground test system, which comprises a signal control sub-system, an orbital data generation sub-system, a navigation database sub-system, a pulse contour extraction sub-system, a navigation parameter estimation sub-system, a large-scale dynamic effect sub-system, an X-ray pulsar signal simulation sub-system, a detector sub-system and a navigation demonstration sub-system, wherein the orbital data generation sub-system comprises a Walker constellation satellite orbit module, a lunar exploration module and a Mars exploration orbit module; the large-scale dynamic effect sub-system comprises a large-scale space effect simulation module and an in-orbit dynamic effect simulation module; and the X-ray pulsar signal simulation sub-system comprises an X-ray generator and a vacuum channel. By realistically simulating the radiation characteristics of pulsar X-ray photon signals in a large-scale dynamic environment, the performance of a pulsar navigation probe is subjected to a closed loop test, the pulsar navigation algorithm is examined, and the feasibility of the scheme design of the pulsar navigation system is verified.

The invention discloses a constellation orientated simulating system and method based on an X-ray pulsar. The constellation orientated simulating method is characterized by comprising the steps of measuring a relative distance between stars by using an equation of light spread by an inter-star link or X-ray pulsar signal between satellites, obtaining an included angle between satellite base lines in a constellation, meanwhile, extracting a pulsar radiation direction vector by a satellite borne X-ray detector and a collimator which are matched, calculating an included angle between the vector and the satellite base lines, further calculating an included angle between the vector and the plane of the constellation, measuring integral rotation and drift of earth orbiting satellites or constellation and correcting. The constellation orientated simulating system based on the X-ray pulsar comprises a signal simulating unit, a time maintaining unit, a modulation unit, a controllable light time delay unit, an optical sending unit, an optical receiving unit, a photon detecting unit and an oriented simulating unit. The constellation orientated simulating system is capable of performing analogue simulation on realization of signal generation, transmission, acquisition, processing and oriented algorithm in the process of orienting the X-ray pulsar.

The invention discloses an X-ray pulsar navigation positioning method and system based on nonlinear prediction strong tracking traceless Kalman filtering. The navigation positioning method comprises the following steps of taking a spacecraft position vector and a velocity vector as a navigation state variable, establishing a navigation system state model and obtaining a spacecraft state predictionvalue; determining a pulsar signal observation value and establishing a navigation system observation model; using a non-linear prediction strong tracking traceless Kalman filtering method to processa pulsar signal observation value and a spacecraft state prediction value, in the spacecraft state prediction stage, acquiring a minimum navigation system state model error according to a constraintfunction, and correcting a navigation system state model error in a quasi real-time mode; and in a spacecraft state updating stage, introducing a fading factor to suppress a noise interference, predicting and updating the state of a spacecraft. A spacecraft state model error is estimated and corrected, and simultaneously, the problems of filter divergence and the low precision of X-ray pulsar navigation caused by the noise interference are solved.

The invention discloses a doppler differential velocity model and a method for combined navigation by using a doppler differential velocity model and an X-ray pulsar. The doppler differential velocity model is Y<s>(t)=h<s>(X, t)+omegav, wherein omegav is doppler measurement noise; Y<s> and h<s> respectively represent a measurement value and a measurement equation; Y<s>=vD2-vD1; the equation is as shown in the specification. The method for combined navigation by using the doppler differential velocity model and the X-ray pulsar comprises the following steps: 1, building an orbital dynamics model of a deep space probe; 2, building an X-ray pulsar navigation ranging model; 3, building the doppler differential velocity model; 4, filtering by using an extended kalman filter. Compared with the prior art, the doppler differential velocity model has the advantages that (1) compared with the existing pulsar/doppler combined navigation methods, the doppler differential velocity model still can normally and stably work under an unstable solar spectrum; (2) compared with the pulsar navigation method and the doppler navigation method, a plurality of navigation messages are fully utilized by the method, the method has complete observability, and the locating information with higher precision can be provided.

The invention discloses a maximum likelihood phase estimation method based on an X-ray pulsar. The maximum likelihood phase estimation method based on the X-ray pulsar comprises the following steps: constructing an X-ray pulsar signal Poisson model structual unit according to the process for measuring the arrival time of a photon which is striken to a detection material of an X-ray detector; fitting the X-ray pulsar profile by utilizing a plurality of Gaussian distribution probability functions and constructing an X-ray pulsar signal simulation structural unit; constructing a maximum likelihood estimation unit for estimating the initial phase and cycle; and constructing a phase parallel computing unit for improving the peak value searching performance of a cost function in a new model. Not only is the calculation quantity reduced, the calculation time is shortened, but also the high operation precision is ensured, and the maximum likelihood phase estimation method based on the X-ray pulsar has significant meaning in studying the X-ray pulsar signal navigation.

The invention relates to a large-area X-ray pulse detection device based on microchannel plate split joint. The large-area X-ray pulse detection device comprises an X-ray photoelectric cathode, a first insulating layer, a microchannel plate (MCP) input electrode press ring, a second insulating layer, an MCP input electrode, a first MCP layer, an intermediate electrode, a second MCP layer, a third insulating layer, an MCP output electrode, a fourth insulating layer, and an anode which are sequentially stacked up, wherein the first MCP layer and the second MCP layer are both large-area MCP detectors, and each MCP detector comprises a detector body, a split-joint framework and a processing circuit. The large-area X-ray pulse detection device resolves the technical problems that an existing MCP detector is adopted to detect the X-ray pulse, extremely long observation time is needed, and detection efficiency of the whole system is low, a detection method and a device which are high in detection efficiency are provided for an X-ray pulsar navigation system, photon measurement information with high time resolution and high time accuracy is provided for X-ray pulsar navigation, and guarantee is provided for high precision of navigation positioning.

The invention relates to a deep space explorer acquisition phase celestial navigation method based on target object ephemeris correction. According to the method, firstly, a Martian explorer state model, a startlight angle navigation sub system measuring model and an X-ray pulsar navigation sub system measuring model are built; then, the startlight angle and the X-ray pulsar quantity measurements are respectively obtained; filtering estimation is performed to obtain the position and the speed of a detector in a heliocentric inertia coordinate system and a target object center inertia coordinate system; on the basis, a state model and a measuring model of target object ephemeris error are built; the quantity measurement about the target object ephemeris error is obtained through estimation state vectors of the startlight angle navigation sub system and the X-ray pulsar navigation sub system; a Kalman filtering method is used for estimating the target object ephemeris error; the target object ephemeris error is fed back into a navigation system model; the position of a target object in the navigation model is corrected. The deep space explorer acquisition phase celestial navigation method belongs to the technical field of aerospace navigation, can be used for estimating the object ephemeris error and correcting the model error of the navigation system on line, and is applicable to the explorer acquisition phase.

The invention discloses a Mars final approaching section autonomous navigation method based on relative measurement information, and belongs to the technical field of deep space exploration. For achieving Mars final approaching section autonomous navigation, a final approaching and surrounding dynamic model is established. According to differential information of X-ray pulsar arrival time and Doppler velocity measurement information of a Mars orbiter, based on nonlinear filtering algorithm, the states of an approaching detector and the Mars orbiter undergo joint estimation, absolute navigation is achieved through utilization of two kinds of relative measurement information including the differential information of X-ray pulsar arrival time and the Doppler velocity measurement information of the Mars orbiter, and the accuracy of Mars final approaching section autonomous navigation and the accuracy of entry point state estimation are improved. The method has the following advantages: introduction of a planet ephemeris error is avoided, the adverse effect on navigation performance due to nondeterminacy of pulsar parameters is limited, the problem of state divergence resulting from long observation time of pulsars is overcome, the navigation performance of two detectors is improved at the same time, and the navigation filter accuracy and the convergence speed are increased.

The invention discloses a spacecraft attitude and position measurement system and method based on an X-ray pulsar. According to the system, a satellite-borne X-ray detector is matched with a collimator to acquire pulse arrival time and accurately acquire a pulsar radiation direction vector, and a geocentric direction vector is acquired by virtue of an infrared or ultraviolet horizon sensor; a navigational computer finishes a pulsar timing observation navigation algorithm, a pulsar positioning algorithm based on angular distance measurement and a pulsar fixed attitude algorithm based on angular distance measurement respectively under a geocentric coordinate system and acquires the position, speed, attitude and in-orbit movement direction of a spacecraft in real time through the several algorithms according to the pulse arrival time, the radiation direction vector and the geocentric direction vector, the autonomous navigation of an orbiting satellite is finished, and high-precision position, attitude and speed information is output. The system is applied to autonomous control on orbiting satellites or constellations of the earth or other planets.

The invention discloses a formation-flying-oriented relative navigation speed measurement and combined navigation method. Relative navigation speed measurement comprises the following steps of acquiring relative speeds of each space vehicle and each navigation star, calculating a difference value between the speed of each space vehicle and the speed of each navigation star, and constructing a relative speed measurement model based on starlight Doppler. The combined navigation method comprises the following steps of constructing a formation-flying-oriented orbit dynamics model, constructing an X-ray pulse star navigation ranging model, constructing an inter-star link ranging model, and constructing a relative navigation speed measurement model based on the starlight Doppler. An expanded kalman filter is used for filtration; during pulse star observation, a measurement model in the filter adopts the formation-flying-oriented orbit dynamics model and the relative navigation speed measurement model based on the starlight Doppler and is also integrated with the X-ray pulse star navigation ranging model once the pulse time of arrival is acquired.

The invention provides an X-ray and charged particle detector based on graphene electric field effect and a detection method thereof, belongs to the technical field of radiation detection and relates to a novel X-ray and charged particle detector structure. The X-ray and charged particle detector based on graphene electric field effect comprises a semiconductor substrate, a gate electrode, an insulating buffer layer, a source electrode, a drain electrode, a graphene detection layer, a graphene voltage measuring electrode and a constant-current supply electrode. The detector has relatively high energy resolution and time resolution simultaneously, and is applicable to the application fields of X-ray pulsar navigation and traditional radiation detectors and is used for detecting X-rays and charged particles such as alpha rays and beta rays.

The invention discloses an interplanetary autonomous navigation ground test verification system based on information fusion. The interplanetary autonomous navigation ground test verification system comprises a navigation sensor, a dynamic celestial body simulator, an X-ray pulsar signal simulator, a navigation calculation module, a shading cover, a simulation main control module and a mechanical turntable, wherein the navigation sensor is arranged on the mechanical turntable; the simulation main control module sends an instruction to the navigation calculation module; the navigation calculation module receives the instruction, controls the navigation sensor to image a celestial body image generated by the dynamic celestial body simulator and sends a celestial body imaging result to the navigation calculation module; the navigation calculation module receives the imaging result and then calculates position information of a spacecraft; and furthermore, the navigation calculation module also calculates the position information of the spacecraft according to a received pulse signal of the X-ray pulsar signal simulator and calculates the position information of the spacecraft by an information fusion algorithm. By the interplanetary autonomous navigation ground test verification system, the authenticity and the reliability of ground simulation verification of an autonomous interplanetary navigation technology are improved.

The invention relates to an X-ray focusing optical system which comprises a lens cone, a reflector set and a supporting frame. The reflector set and the supporting frame are arranged in the lens cone, the reflector set is of a multi-layer sleeve structure formed by nesting a plurality of single-layer reflectors, the single-layer reflectors are in rotational symmetry about an optical axis, a reflecting face is arranged on the inner surface of each single-layer reflector, the inner surface of each single-layer reflector in the shape of a conical curved face, the radial distance between the single-layer reflectors is changed gradually, the single-layer reflectors are confocal, X rays incident in parallel or in approximately parallel can be focused in a grazing incidence mode through one-time reflection. The X-ray photon collecting efficiency can be effectively improved, and the simple, convenient and efficient focusing optical system is provided for detecting weak X-ray photons under the condition of X-ray pulsar navigation and X-ray communication and other non-imaging application conditions.

The invention discloses a precise and synchronous positioning and time-keeping method and system of a Mars orbiting detector. The precise and synchronous positioning and time-keeping method comprises the following steps: firstly inputting initial data including a simulated nominal orbit and relative parameters for filtering initialization; simulating observation data, and simulating the observed quantity of a pulsar according to a measurement equation of the pulsar, wherein measurement noises relative to the observed quantity comprise clock errors, and the clock errors are simulated by a clock error model; and performing adaptive Kalman filtering according to a filtering state equation and an observation equation of self-positioning and time keeping of the Mars orbiting detector to obtain orbits and the clock errors of the detector. According to the precise and synchronous positioning and time-keeping method and system disclosed by the invention, on the basis of establishing an observation model of an X-ray pulsar, the observation model, a detector kinetic model and the clock error model of a satellite-borne atomic clock are organically combined, and the position, speed and clock error parameters of the detector are also estimated so as to ensure that the clock error correction can be achieved, influences of the clock errors to the positioning accuracy can also be weakened, and the self-positioning accuracy can also be improved.

The invention provides a focusing performance analysis method for a grazing incidence optical system based on X-ray optical simulation. The method fully considers characteristic information of X-ray photon energy and reflectivity, irons out a defect in the prior art that only single-energy X-ray photons are considered and the reflectivity is not considered, can achieve engineering actual condition closer to X-ray pulsar navigation apparatus, and improves the efficiency of X-ray optical simulation and analysis. The method can achieve the analysis of the focusing performance of an optical system under the conditions of thermal deformation, structural deformation or thermal-structural coupling deformation, and obtains the mean square root radiuses of a disc of confusion of the optical system, 100% energy concentration ratio and 50% energy concentration ratio under different conditions, thereby achieving the quantification of impact degree on the focusing performance of the optical system from different deformations, and providing support for the reliability design and optimization of a product.

The invention discloses a fast cyclostationary possion signal simulation method and hardware for realizing the method. According to the simulation method, the standard accumulation contour of cyclostationary poisson signals can be fitted by utilizing a Gaussian model. The implementation mode of the algorithm is summarized as follows: decomposing the standard accumulation contour of cyclostationary poisson signals into sub Gaussian component contour curves by utilizing a Gaussian fitting method, generating a photon sequence through sub Gaussian component contours, introducing a poisson model to control the signal flow intensity of the photon sequence, vice versa, synthesizing all sub component photon sequences to obtain the photon sequence of the fitted contour, and generating a simulation signal through the fitted contour. The fast cyclostationary poisson signal simulation method and the hardware system thereof are applicable to fast generation of poisson signals in navigation simulation systems of X-ray pulsar navigation and the like.

The invention discloses a chaotic frequency measuring system and a method in a similar micro-photon source navigation system, mainly solving the problems that low SNR micro-photon signal frequency in a similar photon source advanced navigation positioning and time synchronization system is hard to measure or has low measurement precision. The system is mainly composed of a photon detector, a sampling integrator, a chaos detector, a phase path analyzer, an evaluation unit, a parameter setting unit and other modules. The frequency measuring method of the invention comprises the following steps: inputting micro-photon pulse profile information obtained by sampling integration to a chaos detection model; analyzing the plane of the phase path to determine a critical chaos state parameter; obtaining a frequency parameter by a chaotic frequency measuring principle and a realization method; and carrying out evaluation. The invention has the characteristics that the low SNR micro-photon signal frequency can be accurately detected and recognized under the environment of strong noise. The invention can be used for measuring, calibrating and recognizing the signal resource frequency of advanced navigation systems, such as X-ray pulsar, quantum and the like, and can expand to application fields, such as radar multi-base signal reception, other SNR signal detection and the like.

The invention discloses a frequency domain weighting phase comparison method for X-ray pulsar photon sequences and solves the problems that in the prior art, detailed information of a useful signal is lost, calculation complexity is high, and the signal to noise ratio is low. The method comprises the following steps: 1, conducting evenly-spaced sampling on two photon arrival time sequences received by two spacecrafts, and obtaining corresponding photon intensity sequences; 2, converting the two photon intensity sequences in a time domain into a frequency domain through an FFT; 3, extracting phase information of the two photon intensity sequences, conducting subtraction arithmetic, and obtaining phase differences between the two photon intensity sequences; 4, accumulating the phase differences which are sectionalized, and extracting ratios of the phase differences to corresponding frequency points; 5, conducting energy weighting and proportional multiplication on the ratios of the phase differences to frequency in the frequency domain, and obtaining a normalized delay phase within the time domain. By means of the frequency domain weighting phase comparison method, phase estimation accuracy can be effectively improved, calculation complexity can be lowered, and the method can be applied to estimation of the relative movement state of an X-ray pulsar relative to a navigational positioning system.

The invention discloses a precision temperature control device for an X-ray pulsar navigation sensor; the precision temperature control device comprises a heat isolation pad, an outboard temperature control loop, a front wheel disc, a first heat isolation assembly, a second heat isolation assembly, a temperature sensor, a detector, a heat isolation gasket, a detector mount, a cabin temperature control loop, a heat conductive copper block and a heat conductive copper belt; the heat isolation pad, the outboard temperature control loop and the front wheel disc are connected in sequence; the first heat isolation assembly is arranged on an optics lens; the temperature sensor is wrapped on an optical bench by the second heat isolation assembly; a preamplifier assembly is provided with the detector mount and the heat isolation gasket; the detector, the cabin temperature control loop, the heat conductive copper block and the heat conductive copper belt are connected in order; the precision temperature control device can fully consider light, machine, electric, heat and space track environment conditions, and can respectively use different temperature control means for different assemblies, thus adapting to different heat environments, effectively ensuring normal works of each assembly, realizing integral temperature control optimization of the device, and solving the problems that a conventional satellite platform temperature homogeneity is poor.