139 results about "Pulsar" patented technology

A system and method for navigation utilizes sources of modulated celestial radiation. A spacecraft, satellite, or other vehicle (12) has one or more modulated radiation sensors (22a-22x) mounted thereto for detecting a modulated signal (14) generated by one or more pulsars or other celestial objects (16). A timer (24) measures the pulse time of arrival at a respective pulse sensor (22a-22x) by comparing the pulse signal (14) with a known pulse profile, and a processor (30) calculates a timing difference between the measured pulse time of arrival at sensor (22a-22x) with a calculated pulse time of arrival at a selected reference point (100). The positions and pulse profile characteristics of the pulsars (16) are stored in a digital memory (34) and combining the calculated time difference with the known positions of pulsars (16), the navigational parameters, such as position, velocity, and attitude, for spacecraft (12) with respect to the selected localized reference point (100) can be calculated.

The invention discloses a satellite autonomous navigation system and a satellite autonomous navigation method integrating a pulsar radiation vector and timing observation. The system obtains pulse arrival time and accurately obtains a pulsar radiation direction vector by using a time distinguishing detector and a collimator, and obtains a geocentric direction vector by using an infrared or ultraviolet horizon sensor; a navigation computer respectively completes a pulsar timing observation navigation algorithm under a geocentric coordinate system, a pulsar positioning algorithm based on angular distance measurement and a geometric orientation algorithm based on angular distance measurement by using the pulsar pulse arrival time, the radiation direction vector and the geocentric direction vector, and obtains the position, the speed, the attitude and the on-track movement direction of a spacecraft through integration of several algorithms, so as to complete the autonomous navigation of an orbiting satellite, and output high-precision position, attitude and speed information. The system is suitable for autonomous operation control of orbiting satellites or constellations of the earth or other planets.

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 autonomous relative navigation method for multi-information fusion formation spacecrafts, belonging to the field of aviation and space and aiming at solving the problem that current relative navigation in a manner of GNSS plus inter-satellite link leads to no navigation redundancy information so that navigation precision is low. The method according to the invention comprises the steps: absolute navigation information of nodes of a spacecraft is obtained by utilizing a pulsar navigation system and a GNSS satellite navigation system; time synchronous information and distance information in relation to the nodes of other spacecrafts are obtained via a laser link system or a microwave link system and are used for the relative navigation of formation flying of the spacecrafts; the absolute navigation information completes inter-satellite information interaction with the nodes of other spacecrafts via the laser link system or the microwave link system in order to acquire inter-satellite information interaction data of the nodes of other spacecrafts; and in combination with the inter-satellite information interaction data of the nodes of other spacecrafts, the relative navigation information is acquired by processing the absolute navigation information via a house-keeping management system and is used for the relative navigation of formation flying of the spacecrafts.

The invention relates to an autonomous navigation method for a planet in a final approaching section, which belongs to the field of deep space exploration. The method comprises the following steps: establishing a state model of the planet in the final approaching section; carrying out radio measurement and communication through a detector and planetary orbiters determined by n positions, observing m pulsars and establishing an autonomous navigation measurement model of the planet in the final approaching section; and calculating the state of the detector through navigation filtering based on the two models. According to the invention, measurement characteristics of pulsar navigation and radio navigation are combined in the autonomous navigation method, a non-linear filtering method is employed, so autonomous navigation of the planet in the final approaching section is realized, precision and instantaneity of autonomous navigation of the planet in the final approaching section are improved, and the autonomous navigation method has good exploitativeness and high measurement precision and can satisfy the requirement for instantaneity of autonomous navigation.

The invention discloses an accumulated pulse profile time delay measurement method by sparse representation, and aims to mainly solve the problem that the sampling frequency and signal to noise ratio of pulse profiles can affect measurement accuracy in the prior art. The method is realized by the steps of: (1) conducting standard pulse profile sampling, and constructing a waveform matching redundant dictionary; (2) employing a greedy optimization algorithm to calculate a first-order sparse coefficient vector of the measurement pulse profile under the waveform matching redundant dictionary; and (3) according to the column corresponding to the only nonzero element in the first-order sparse coefficient vector, calculating the accumulated pulse profile time delay. Compared with the prior art, the method provided in the invention significantly reduces computation, improves the measurement precision of time delay, shortens the pulse profile accumulation time, and can be used for measurement of the time difference of arrival (TDOA) of the pulse from a spacecraft to a solar system barycenter.

The invention relates to a combined estimation method of pulsar navigation position and speed. The invention belongs to the field of spacecraft autonomous navigation. According to the method, an observation interval is divided into a plurality of sub-intervals; in each observation sub-interval, pulse signals are superimposed according to a pulsar radiation period, such that a pulse accumulation sub-contour is obtained; the pulse accumulation sub-contour is processed with a quasi-maximum likelihood estimation method, such that a pulse arrival time of each sub-interval is obtained; and according to the pulse arrival times, spacecraft position and speed are estimated with a least square estimation method. The method provided by the invention provides high-precision positioning and speed determination, which are close to those of Cramer-Rao lower bound. Also, a computation amount is low. Therefore, the method provided by the invention has important practical significance upon spacecraft autonomous navigation based on pulsar.

The invention provides a pulsar observation device, system and method. Accurate time interval information can be obtained by counting a sampling clock, the time information of sampling time and sampled data are input into a data frame together to ensure highly consistent time and signal, the integer seconds obtained by time synchronization of a hydrogen atomic clock and a GPS receiver and the decimal seconds obtained by counting the sampling clock are utilized to acquire time information, thereby acquiring nanosecond scale high precision pulsar signal arrival time, and greatly improving the precision and accuracy of pulsar observation. In order to avoid the time error caused by data transmission loss, a network checking head is added in the data frame, compensation can be carried out if data frame loss is found, thus guaranteeing the data integrity and time continuity of long-time observation, and being of important significance to pulsar observation data processing.

The invention relates to a traffic signal mode field, discloses a method for a supermode of traffic signal control: String Supermode, its main steps includes: 1)get String Supermode instruction; 2)set the basic parameters of String Supermode: subareas of a roadnet, period-redistribution; 3)set 2D greenwave mode in the relative subareas according to a String Supermode structure; 4)calculate the 2D greenwave time-offsets and their interim-period in each subarea; 5)run new mode after the above interim-period run out. The present invention realizes the effectiveness of signals equilibrium, high effieciency, multi-purpose, universe, easy to use: vehicles entering Wormhole-area from any direction and going to any position of the diagonal far-corner area, need 4.5 times of red lights on average, no matter how large a Wormhole-class controlled area and how big the number of intersections in the area are, multiple-class-change based on Wormhole-class presents the functions of the fast inhalation of vehicle flow from omni-direction, :the fast spitting out of vehicle flow to omni-direction, the relieving jammed vehicle flow during spitting out to omni-direction, the relieving jammed vehicle flow during inhalation from omni-direction, the coordinating artery roads to quickly shunting vehicle flow, and also, the vehicles' going through an area by only 1 red light of Pulsar-class; this String Supermodes are determined by only about 20 of parameters, can switch rapidly with no redundance, provide an area-type traffic control, analysis, operation basic mode.

The invention relates to a 1.3-centimeter-waveband dual-polarized refrigeration receiver dewar used for observing molecular spectra lines, pulsar and VLBI (very long baseline interferometry) in the radio astronomy. The receiver dewar consists of a dewar cavity, a shielding cover, a microwave window, a frame carrier, a support, a ring-shaped fixing frame, a soft connector, a feed source, a transition waveguide, a circle and square converter, a polarizer, a low-noise amplifier, a waveguide coaxial converter, an isolator, a semi-rigid coaxial cable, a microwave window sealing film, a microwave window fastening ring, an air-filled cavity, an air-filled cavity sealing film, an air-filled cavity fastening ring, an air cylinder and a refrigerator. The 1.3-centimeter-waveband dual-polarized refrigeration receiver dewar with high sensitivity has the advantages that the design scheme is more reasonable, good sealing performance is ensured, internal devices can be well fixed and supported, the refrigeration effect is more excellent, the stability is better, the sensitivity is higher, and the thermal radiation can be effectively isolated, thereby being capable of being better applied to high frequence radiation characteristic study of molecular spectra lines and pulsar and radio astronomy observation of VLBI.

Disclosed is a system for updating a reference time from a decaying rotational period of a pulsar. The system can include: a database (DB) configured to store: coordinates for a pulsar; a recorded rate of rotation (RROR) for the pulsar; a rotational rate of decay (RROD) function for the pulsar; and a recorded reference time for the pulsar. A sensor can be configured to collect electromagnetic pulsar radiation from the pulsar and generate sensor data. A signal processor module can be configured to receive the sensor data, generate an observed rate of rotation (OROR) signal profile, generate a current rate of rotation (CROR) for the pulsar from the OROR signal profile, and update the RROR from the CROR. A time processor module can be configured to receive the RROD function and the CROR, and to solve the RROD function to output a reference time of the pulsar.

The invention provides an optical and pulsar fusion type self-navigating method based on observability analysis. The optical and pulsar fusion type self-navigating method comprises the following steps of firstly, mounting an optical sensor and a pulsar sensor on a detector to respectively detect a gazing direction of a single asteroid and time that pulse reaches the detector; secondly, respectively establishing an observation equation of optical navigation and an observation equation of pulsar navigation, and combining the observation equations to be an observation equation of a fusion navigation system; and finally, selecting an asteroid capable of being detected and a pulsar as measurement navigational stars, and calculating a navigation position and a navigation speed by using standard Kalman filtering.

The invention provides an aircraft navigation method based on earth high orbit-earth and moon libration point heterogeneous constellations. The aircraft navigation method comprises the following steps of firstly, utilizing a pulsar detector and intersatellite ranging observing equipment to obtain the corresponding pulsar and intersatellite ranging observing amount, so as to realize the autonomous navigation of the earth high orbit-earth and moon libration point heterogeneous constellations; after the heterogeneous constellation realizes the autonomous navigation, arranging the intersatellite ranging observing equipment on the aircraft, and observing the heterogeneous constellations to obtain the corresponding position information; using a corresponding navigation method to determine the self position and speed, so as to realize the autonomous navigation of the aircraft. Compared with the navigation method based on a ground measuring and controlling system, the aircraft navigation method based on the heterogeneous constellations has the characteristics that the communication delay is little, the signal attenuation is little, the positioning accuracy is high, and the navigation efficiency is high.

The invention discloses a pulsar signal detector based on single event effect, relating to the technical field of data processing and solving the problems of support defect of low-pressure high-vacuum and low-temperature environment and overlarge detection area of the traditional detector. The pulsar signal detector comprises a register unit array comprising M+1 register units and an adder array comprising M adders, output ends of the first register unit and the second register unit are respectively connected with the first input end and the second input end of the first adder, the output end of the first adder is connected with the first input end of the second adder, the output end of the third register unit is connected with the second input end of the second adder, the carry output end of the first adder is connected with the low-level carry input end of the second adder, by suck analogy, the output end of the mth adder is connected with the first input end of the (m+1)th adder, the output end of the (m+2)th register unit is connected with the second input end of the (m+1)th adder, and the carry output end of the mth adder is connected with the low-level carry input end of the (m+1)th adder, wherein m is more than 1 and less than M; and the output end of the Mth adder is used as a final result output end. The invention is applied to detecting pulsar signals navigated by spacecrafts.

The invention relates to the technical field of astrophysics, and in particular relates to a method for eliminating the interference of a broadband time domain in pulsar arrival time data. The method comprises the following steps: observing a pulse signal of a pulsar, obtaining a periodical pulse outline of the pulsar, eliminating a dispersion delay of the periodical pulse outline of the pulsar, observing broadband radio interference in the pulse signal data of the pulsar, and eliminating the interference of the broadband time domain in the pulsar arrival time data. By utilizing the correlation of the broadband time domain interference, the broadband time domain interference is eliminated by virtue of channel subtraction so as to eliminate the broadband time domain interference in the pulsar observation data, a real pulsar outline is obtained, the precision of the pulsar arrival time is improved, and the observation and research of the pulsar arrival time can be more reliably guaranteed.

A magnetized pulsar ring of the invention is a pulsar ring fixed to an outer peripheral surface of a supporting member and including a ring body in which a number of magnetic poles are at predetermined intervals in a peripheral direction. The ring body 11a is formed of a plastic magnet, and has a cushion member made of an elastic body that is interposed between the ring body and the outer peripheral surface.

The invention discloses a pulsar photon timing method based on an APD detector. An APD is used for realizing detection on weak pulsar photons of 0.5keV to 10keV. On one hand, the pulsar photon timing method has the advantages of high detection efficiency, rapid response time, high energy resolution and the like; on the other hand, photon-generated carriers in the detector are drifted along a pn junction direction; time jitter caused by the detector is relatively small, so that the pulsar photon timing method is very suitable for pulsar photon timing; a constant-ratio timing and single threshold value triggering method is adopted, so that noises are inhibited, and furthermore, an amplitude movement effect caused by different X photon energy is eliminated; advantages that a GPS (Global Positioning System) second pulse signal is long and stable and an atomic clock is short and stable are combined, and long and stable and high-precision clock frequency is output through a correction principle; TDC (Time-Digital Convert) timing precision is kept; furthermore, pulsar photon timing errors are reduced.

The invention relates to a pulsar identification method based on a convolution neural network, belonging to the pulsar identification technical field. The invention iteratively trains the sample training set through the convolution neural network, thereby realizing the recognition of pulsars by using the trained convolution neural network model. The method converts the problem of pulsar recognition into the problem of image recognition and classification, which can identify pulsars quickly and accurately. Moreover, the method can maximize the use of more pulsar features, avoid the process of traditional manual feature design, greatly save time and cost, has real-time and simplicity, and is easy to be popularized and applied in practice.