30 results about "Single star" patented technology

The invention discloses a multi-type satellite collaborative observation task planning method based on deep reinforcement learning, and belongs to the technical field of satellite task planning. The method comprises the following steps: firstly, acquiring attributes of multiple types of satellites and attribute information of observation tasks such as single-satellite, double-satellite cooperation and three-satellite cooperation; then, constructing a multi-dimensional constraint model; a deep reinforcement learning decision model based on the Seq2Seq architecture is built, a coding layer extracts position information for relative position coding, and a decoding layer outputs a task-satellite allocation scheme and an execution sequence; an Actor-Critic algorithm is adopted to train the model, and minimization of loss of an uncompleted task is taken as a target optimization strategy. The problems that a traditional satellite task planning method is difficult in multi-constraint balance, low in calculation efficiency and weak in generalization ability are solved, and the method has the advantages of being high in multi-constraint fusion ability, high in calculation efficiency, excellent in generalization performance and remarkable in income optimization and can be effectively applied to the fields of agricultural monitoring, disaster emergency, environmental governance and the like.

The invention discloses a radar imaging detection satellite constellation design method, which comprises the following steps of: decomposing a constellation into a plurality of orbit surfaces, uniformly describing each orbit surface through four parameters, constructing an asymmetric constellation structure, and establishing a multi-target optimization model for solving by taking the total cost of the constellation, the maximum revisit time and the detection performance as targets. Non-dominated quantizer sorting is introduced in the sorting process, and satellite constellation design is completed. According to the method, single-satellite-based optimization of the salted fish is converted into orbital plane-based optimization, the optimization variable dimension is remarkably reduced, the method is particularly suitable for large-scale constellation design comprising hundreds of satellites, meanwhile, the Pareto frontier is obtained through non-dominated sorting, various constellation configuration schemes emphasizing different performances are provided, and the method is suitable for large-scale constellation design. Compared with an existing constellation design method, the problems that the to-be-optimized parameters are increased along with the number of satellites, and efficiency is low are solved, the scheme output by the algorithm is more reasonable through the improved sorting mode, and the method can be used for constellation design.

The application discloses a kind of online calibration methods of multi-antenna navigation darkroom link delay, belong to satellite navigation user equipment test field.The application includes: by metrology / testing, the receiving zero value of calibration receiver at each frequency point is obtained;Navigation signal link delay calibration environment is constructed in multi-antenna navigation darkroom;Single star multi-output navigation signal simulator transmits single star single frequency point test signal;The current channel link delay is obtained by calibration receiver;Change single star multi-output navigation signal simulator output signal frequency point and obtain other frequency point link delay;Change signal output channel and obtain the link delay of each frequency point of other channel.The application can realize the automation online calibration of multi-antenna navigation darkroom link delay, can effectively shorten system calibration time, reduce the advantages of link delay calibration complexity.

This invention discloses a single-satellite orbit design method, system, and electronic equipment. Based on the orbital parameter description method using correlation coefficient k, this design method proposes orbit configuration optimization methods for both plane angle optimization and vector angle optimization. Considering avoidance constraints and imaging constraints, an objective function for correlation coefficient k is obtained. Further simulations yield single-satellite orbits for observation of key points on the space station. This invention significantly simplifies the traditional optimization process, providing a rapid design optimization algorithm for single-satellite orbit configurations in specific regions or random locations on the space station.

The application discloses a kind of low orbit single-satellite Doppler static positioning method, equipment and storage medium of integration, the method includes using ephemeris information to calculate the position, velocity and clock drift of satellite at each observation epoch;According to time window, Doppler frequency shift observation value is integrated, and observation data set is obtained;Based on the position, velocity and clock drift of satellite at each observation epoch, a plurality of candidate initial positions are screened from observation data set, and the plurality of candidate initial positions are sorted;With the first candidate initial position as iteration initial position, positioning solution is carried out, and position solution is obtained;Based on position solution, velocity solution is calculated, and velocity solution is obtained;Judge whether velocity solution satisfies velocity constraint, if yes, then output corresponding position solution;If not, then take the next candidate initial position as iteration initial position, and repositioning solution is carried out.The application directly uses Doppler frequency shift observation value to quickly screen out candidate initial position, without prior position in advance.

The application discloses a milling cutter with star-shaped line cutting edges and an optimization method thereof, and relates to the technical field of milling cutter design, which comprises the following steps: determining the initial value of a scale factor based on production target parameters, adjusting the initial value in combination with the hardness value of a machining target material and cutting process parameters to obtain the accurate scale factor of a single star-shaped line cutting edge, constructing a milling cutter model, establishing a plane coordinate system at the center of a cutter head, determining the curvature of the star-shaped line according to a single star-shaped line cutting edge parameter equation containing the accurate scale factor and an angle change parameter, rotating the cutter head center by different angles to form a plurality of star-shaped line cutting edges with different positions, and respectively adopting a circular arc, a spline curve and a helical transition surface to optimize the transition connection between the sharp corners in the star-shaped line cutting edge, adjacent star-shaped line cutting edges and the star-shaped line cutting edge and the cylindrical surface of the cutter head, so as to help optimize the load distribution during cutting, reduce vibration and wear.

The invention discloses a satellite-borne microwave general positioning method, which is used for single-satellite multi-orbit positioning when a ground radiation source searches and traverses an airspace in the air, and comprises the following steps of: determining a sub-satellite point visual circle radius according to a satellite orbit height; determining the possible position of the ground radiation source according to the M sub-satellite point positions and the visible circle radius, wherein the visible circle intersection corresponding to all the sub-satellite point positions is the possible position of the ground radiation source; aiming at the possible position of each ground radiation source, calculating an azimuth angle and a pitch angle of each sub-satellite point corresponding to the possible position of each ground radiation source, and extracting a corresponding gain array from an antenna pattern; comparing a signal energy array acquired by a sub-satellite point with the gain array, and calculating a variance of an energy gain difference array as a matching criterion; and traversing all the possible positions of the ground radiation source, and averaging the positions with the minimum variance of 0.5% to obtain a general positioning result. According to the invention, a method of averaging possible positions with the minimum variance of 0.5% is adopted, so that the approximate positioning precision is greatly improved.

The invention relates to a micro-nano satellite group distributed cooperative multi-target tracking method, and belongs to the technical field of space target tracking. Through inter-satellite cooperative networking construction, single-satellite weak and small target detection, single-satellite multi-target tracking, cross-view-field track association, multi-satellite distributed information fusion and the like, the target tracking number of satellite group cooperation can be greater than or equal to 12, and support is provided for the micro-nano satellite group in the fields of space situation awareness, on-orbit target monitoring and the like. According to the method, the problems of poor robustness of a centralized architecture, insufficient cross-view-field tracking precision and the like in micro-nano satellite group multi-target tracking are solved, the real-time performance and reliability of space target tracking are improved, and the requirement for accurate and stable tracking of multiple targets in a complex space environment is met.

The invention discloses a navigation mode transition method, an electronic device and a medium, in a working process of a first navigation mode, geometric angles among a mother satellite, a service spacecraft and space debris are monitored, and when the geometric angles meet a mode switching requirement, the position of a target orbit under a J2000 coordinate system is obtained through double-satellite geometric estimation; and taking the position as an initial position calculated in the second navigation mode, and switching to the second navigation mode. Before the navigation mode is switched, the target orbit position is determined through double-satellite geometric estimation, the single-satellite navigation positioning precision can be rapidly improved, a good initial value is provided for double-satellite angle measurement filtering, and the convergence process is accelerated.

This invention discloses a large field-of-view automatic calibration device and method for pre-calibrating star arrays, solving the problem that existing star array pre-calibration methods cannot directly measure the relative spatial angle relationship between simulators of distant single stars. The calibration device includes a turntable, a calibration unit disposed at the working end of the turntable, and a host computer disposed outside the turntable. The calibration unit includes a mounting base and a starlight detection module, a data fusion module, and a relative spatial angle calculation module disposed within the mounting base. The mounting base is detachably connected to the working end of the turntable, and its side wall has a mounting through hole. The incident end of the starlight detection module is opposite to the mounting through hole, and its signal output end is electrically connected to the first signal input end of the data fusion module. The second signal input end of the data fusion module is connected to the signal output end of the turntable, and its output end is connected to the input end of the relative spatial angle calculation module. The relative spatial angle calculation module is electrically connected to the host computer.

This invention discloses a dynamic clustering method for space-based distributed collaborative detection. First, based on dynamically changing mission requirements and target status, a dynamic clustering algorithm optimized for collaborative detection performance is designed to cluster satellites within the constellation. Then, using the comprehensive capabilities of nodes as a crucial basis for node star election and cluster structure maintenance, a multi-factor weighted dynamic edge node star selection algorithm is designed, ultimately achieving a hierarchical, ordered, distributed collaborative architecture of "constellation-cluster-single star". This invention can reduce the information propagation cost within the constellation and improve information collaboration and mission execution efficiency.

The application provides a distributed star cluster task cooperative planning method based on a contract network, which comprises the following steps: a task receiving star receives a guide task; the task receiving star calculates the task attributes of each star according to a task management star selection rule; a task management star determines the content of a published task contract; after receiving the task, a task execution star feeds back the task information according to the task executability; the task management star collects all the task feedback information, selects the task information with the highest cooperative benefit, and publishes a task execution command to the selected execution star to complete the task contract signing; after receiving the execution command, the selected task execution star executes the task according to the requirements of the prepared contract and feeds back the execution result to the task management star in real time; the task management star receives the execution states of all the execution stars, fuses the target single-star observation information fed back by the execution stars, generates target comprehensive situation information, and sends the target comprehensive situation information to a situation information user.

A distribution method for improving remote sensing constellation target capacity through three-dimensional coordinate different-satellite fusion comprises the steps that two-dimensional coordinates of the same observation target group are generated on two task satellites executing an observation task, and three-dimensional coordinate fusion and numbering sorting are carried out based on the two-dimensional coordinates; distributing the two-dimensional coordinates which are not fused to the satellites which do not execute the observation task according to the upper limit of the capability of calculating the three-dimensional coordinates by the satellites, and performing three-dimensional coordinate fusion by the satellites which do not execute the observation task by receiving the two-dimensional coordinates which are sent by the two satellites and have the same serial number. After the two-dimensional coordinates are successfully fused in the upper limit range of the capability of calculating the three-dimensional coordinates, the two-dimensional coordinates are sent back to the task satellite, the part exceeding the upper limit range of the capability of calculating the three-dimensional coordinates is sent to another satellite which does not execute the observation task, and so on until all the two-dimensional coordinates are fused, and the target tracking capacity of the satellite is increased. The method overcomes the limitation of the calculation capability of the existing single satellite, and provides a mode that the satellites networked in the stationary orbit do not need to interact through a fixed rule.

A spacecraft relative position correction method based on single star angle measurement information, the steps are as follows: (1) based on the initial orbit determination information, recursively calculate the target position of the space target in J2000 system; (2) calculate the estimated value of the relative position of the two stars in the VVLH coordinate system; (3) judge whether the relative position full component error correction condition is satisfied; if the correction condition is satisfied, execute step (4); otherwise, execute step (5); (4) based on the relative position estimate value and the spacecraft line-of-sight angle measurement value, calculate the Moore-Penrose inverse matrix of the first Jacobian matrix of the observation with respect to the relative position, and calculate the spacecraft and space target relative position correction value, complete the spacecraft relative position correction; (5) based on the relative position estimate value and the spacecraft line-of-sight angle measurement value, calculate the inverse matrix of the second Jacobian matrix of the observation with respect to the relative position, and calculate the spacecraft and space target relative position X-axis and Z-axis correction value, complete the spacecraft relative position correction.

The application discloses a kind of large-scale MIMO multi-star positioning and direction estimation method and system based on angle information.The application first obtains the channel matrix estimation between each satellite and user by sending pilot signal;Then the estimated value of channel parameter is obtained using tensor-ESPRIT algorithm, including angle of departure and angle of arrival;According to the estimated angle of departure, the direction vector between user and each satellite is obtained, the optimization problem on spherical surface is established, considering the altitude constraint, the user position estimation value is obtained by using Riemann conjugate gradient method;Finally, according to the estimated user position and angle of arrival, the optimization problem on SO (3) manifold is established, and the estimated value of user array rotation matrix is obtained by using Riemann gradient descent method.The application combines the channel information between multiple satellites and users for positioning and direction estimation, and considers the altitude constraint during positioning, compared with single satellite and unconstrained case, can significantly improve the positioning performance, while having good direction estimation performance.

The invention belongs to the technical field of communication signal processing, and more particularly relates to a same-frequency interference cancellation method and system based on a multi-start satellite operation neural network, and the method can accurately and quickly obtain a target linear interference component of a target receiving signal through calculating an equivalent linear channel response between the target receiving signal and a target transmitting signal. According to the method, by introducing the target nonlinear reconstruction model of the multiple target single-star models, the target nonlinear interference component of the target receiving signal can be quickly and accurately obtained from multiple dimensions by utilizing linear transformation and star operation of two characteristic branches under the condition of not increasing deep convolutional layer stacking or a large number of cyclic structures; therefore, on the basis of the target linear interference component, the target nonlinear interference component and the target receiving signal, effective cancellation of the same-frequency interference signal in a high-speed dynamic change channel environment can be realized.

The invention relates to the technical field of ground task management and control of aerospace earth observation satellites, and discloses an electronic satellite parallel resource scheduling method based on a greedy algorithm. According to the method, a reconnaissance task set obtained through reconnaissance requirements is divided into a real transmission task set and a playback task set, the real transmission task directly allocates resources according to task time, the playback task uses constraints according to various types of satellites, and playback task data transmission resource allocation based on a greedy algorithm is carried out in parallel; according to the method, a multi-satellite data transmission resource scheduling initial solution of an electronic satellite is formed, data transmission resource conflict resolution of each station is carried out, a multi-satellite resource conflict resolution problem of the electronic satellite is modeled as a classic dynamic planning algorithm revenue maximization problem, a resource scheduling allocation scheme with the maximum benefit is obtained, and the feasibility of the scheme is verified by calling a single-satellite plug-in. According to the method, the electronic star resource scheduling is relatively completely described, and the method has the characteristics of advancement, practicability and the like.

The application discloses an in-orbit reference frequency stability estimation method of an inter-satellite link system, which comprises the following steps: calculating a combined phase measurement value Θ p (t) according to a two-way phase measurement value Θ(t) without time scale correction; calculating a relative frequency error δf i ‑δf j ; calculating a relative frequency error sampling value, repeating the sampling according to a nominal sampling frequency, and calculating a relative Allan variance. The application is improved based on the calculation formula of the Allan variance, can accurately estimate the relative frequency stability between two stars of the inter-satellite link, and further estimate the frequency stability of a single star.

The invention relates to a real-time area coverage method and device for medium-orbit area observation constellations, and the method comprises the steps: carrying out the subarea division of a target area, and uniformly generating sampling points and area mask vectors corresponding to the sampling points in the target area; according to the pointing information of the satellites to the target area at the current moment, obtaining a single-satellite instantaneous coverage mask vector of each satellite to the sampling point; counting the coverage multiple number of each sampling point to obtain an instantaneous multiple coverage vector; obtaining an instantaneous region coverage vector according to the instantaneous multiple coverage vector and the region mask vector; according to the instantaneous region coverage vector, calculating an instantaneous i-fold coverage proportion of the sub-region at the current moment; taking a pointing vector formed by all satellites as a decision variable, and constructing a target function according to an instantaneous i-fold coverage proportion; and solving the objective function by adopting a particle swarm algorithm to obtain an optimal pointing vector so as to realize area coverage. According to the invention, a real-time area coverage area observation task can be realized.

The invention relates to an optical positioning method, in particular to a multi-target multi-mode fusion positioning method based on a motion platform, and solves the problem that an existing optical positioning mode cannot meet target positioning requirements for complex application scenes with complex observation backgrounds, long observation distances, multiple and dense target image points and long observation arc segments. When intersection positioning is carried out on multiple targets, laser ranging positioning is carried out on a key main tracking target, intersection measurement positioning is carried out on targets observed by two measurement stations at the same time, single-satellite pure-angle positioning is carried out on a target observed by only a single measurement station, and target positioning can be realized by using single-station and double-station observation data; therefore, the target measurement arc length is increased, and long arc section positioning of more targets can be realized under limited measurement station resources.

The present application relates to the technical field of space target detection, and discloses a star cluster cooperative space target search and orbit determination method, which comprises the following steps: a ground computing center generates prior guidance data of a space target and injects the star cluster; a wide field satellite node performs sky domain search according to the prior guidance data, extracts a two-dimensional observation error covariance through dimension reduction and shift superposition processing, and sends an inter-satellite data frame containing the covariance and instantaneous pose to a narrow field satellite node; the narrow field satellite node receives the inter-satellite data frame, performs reference alignment and state extrapolation in combination with a prior distance error variance and an earth-centered inertial coordinate system, and generates an extrapolated three-dimensional error ellipsoid; the narrow field satellite node generates a boresight maneuver trajectory according to the error ellipsoid to realize physical locking of the target; and the star cluster performs state convergence based on a cross-line-of-sight network to complete cooperative orbit determination. The present application overcomes the problem of limited single-satellite field of view and lack of depth data, and realizes effective capture and orbit determination of a multi-satellite cooperative space target.

The invention discloses a communication and conduction integrated low-orbit single-satellite Doppler static positioning method and device and a storage medium. The method comprises the following steps: calculating the position, speed and clock drift of a satellite under each observation epoch by using ephemeris information; integrating Doppler frequency shift observation values according to time panes to obtain an observation data set; based on the position, the speed and the clock drift of the satellite under each observation epoch, screening out a plurality of candidate initial positions from the observation data set, and sorting the plurality of candidate initial positions; carrying out positioning calculation by taking the first candidate initial position as an iteration initial position to obtain a position solution; performing speed calculation based on the position solution to obtain a speed solution; judging whether the speed solution meets a speed constraint or not, and if yes, outputting a corresponding position solution; and if not, taking the next candidate initial position as the iteration initial position, and carrying out positioning calculation again. According to the method, the candidate initial position is quickly screened out by directly utilizing the Doppler frequency shift observation value, and the prior position does not need to be known in advance.

The application provides a large-scale constellation earth observation task planning method and device, and belongs to the technical field of satellite task planning. The large-scale constellation earth observation task problem is divided into a multi-star cluster cluster allocation problem and a single-star cluster cluster autonomous task planning problem by the application, an improved adaptive large neighborhood search algorithm combined with tabu search is used to allocate the large-scale constellation earth observation task to different star clusters, and then a star cluster autonomous task planning algorithm based on an extended contract net mechanism is used to realize multi-star task planning in the star cluster. In this way, the problem scale can be reduced, the search space can be greatly reduced, the solving efficiency can be improved, the cooperation between satellites in the star cluster can be increased, especially in the face of satellite damage and interference, the anti-interference ability and cooperative completion efficiency of the task can be improved, and the robustness and reliability of the task planning can be ensured.

The application discloses a single-star target line-of-sight atmospheric refraction correction method and system based on multi-spectral ranging, relates to the field of atmospheric refraction processing, and comprises the following steps: determining a target radiation intensity ratio based on two radiation intensities on different wave bands at the same time; acquiring observation lines of sight of a satellite on a measured target on different wave bands at the same time, and performing light track tracking to obtain light track trajectories; determining a target grid through by each light track trajectory from an atmospheric grid model, and determining an extinction coefficient of each target grid; combining a radiation intensity calculation formula to construct a target function of a radiation intensity ratio with respect to a height of a target distance from the ground; determining a target height of the measured target distance from the ground based on the target function and the target radiation intensity ratio; determining the position of the measured target according to a track point matched with the target height in each light track trajectory; and combining the position of the satellite to determine a line-of-sight vector after atmospheric refraction correction, so that high-precision atmospheric refraction correction under single-star observation conditions is realized.

The invention discloses a low-orbit remote sensing agile satellite constellation task scheduling method for a dense scene, and a system, equipment, a storage medium and a program product thereof, belongs to the technical field of low-orbit remote sensing agile satellite constellation task scheduling, and aims to solve the problems that the observation time of an agile satellite to a target point is not fixed, the observation sequence is not fixed, and the observation time and attitude adjustment are coupled. And constructing a multi-satellite agile satellite task scheduling combinatorial optimization model by combining constraint conditions such as satellite orbits, satellite maneuvering capability and task types and complex and coupled multi-constraint limitations. An initial solution generation strategy is formulated, an initial solution rapid generation algorithm based on task income and task distribution is designed in a dense area in a dense scene, a subproblem with a moderate scale is constructed from a dense point position set, and then a branch and bound algorithm is used to rapidly obtain an accurate solution of the subproblem. After all sub-problems are solved, a feasible solution of the original problem is constructed, the current feasible solution is used as an initial solution of the original problem, a grouping crossover operator and a mutation operator are designed according to the conflict characteristic of a single-satellite and multi-satellite agile window, and a better result is found by using the global search capability of a genetic algorithm.

The present application relates to sewage treatment technical field, especially to a kind of energy-saving single star sedimentation tank control system based on self-adapting flow rate control, the system is through data acquisition module and collects pool body operating data and environmental perception data;Through steady-state hydraulic model, energy consumption characteristic model and sludge settling characteristic model respectively generate basic flow rate control scheme, basic energy consumption control scheme and settling critical flow rate;According to real-time water quality fluctuation data, hydraulic condition calibration is carried out to basic flow rate control scheme, according to real-time sludge interface position, settling boundary optimization is carried out, according to equipment health index, energy efficiency deviation calibration is carried out, according to power grid load state, energy consumption safety optimization is carried out;Through self-adapting compensation module, equipment aging compensation is carried out;Through collaborative control module, water inlet valve group, sludge discharge mechanism and variable frequency drive system are collaboratively controlled.The present application solves the problems of high operating energy consumption and high equipment failure risk in the prior art.

The invention discloses a method for designing a multi-satellite rendezvous orbit of a Walker constellation without maneuvering of a single satellite under rendezvous constraint, which is characterized in that service satellites are respectively configured for each orbit surface of the Walker constellation, the orbit period difference between the service satellites and constellation satellites is designed, and the traversal rendezvous of the service satellites with all satellites in a target orbit surface without maneuvering is realized. Designing and modeling other orbit parameters into an optimization problem with intersection condition constraints, fusing the intersection condition constraints into an optimization target in a penalty function form, and performing parameter optimization by adopting a genetic algorithm, so as to generate an orbit design scheme meeting the requirement of sequential continuous intersection. The method is suitable for task planning such as periodic patrol reconnaissance and on-orbit service of Walker constellation orbit plane satellites, an efficient and feasible intersection orbit preliminary scheme can be quickly generated in the initial stage of a task, and a good foundation is provided for subsequent task orbit design considering complex factors such as perturbation.

The application discloses a kind of evaluation constellation orbit transfer maneuver multiple reachable coverage method, it is applicable to the quick evaluation of satellite constellation multiple satellite reachable area, belongs to aerospace field.The application implementation method is: in the fixed sphere coordinate system under the earth center, target area is carried out equal-volume dispersion in two dimensions of distance and zenith angle, and with the reachable azimuth interval of discrete unit center line as evaluation index;By calculating the intersection of center line and reachable domain envelope and carrying out detailed judgment, obtain single satellite reachable azimuth interval;Using a node sorting and one-time sequential reading method, obtain the multiple satellite reachable azimuth interval of corresponding target center line, while combining target azimuth angle area for multiple satellite reachable azimuth interval is intercepted;Integrate the multiple satellite reachable interval of all target center lines to obtain the multiple satellite reachable area of constellation to target area, i.e. 2 realize the multiple reachable coverage evaluation of constellation orbit transfer maneuver.The time complexity of the application is compressed to O (n 2 +n).

The invention discloses a milling cutter with an astroid cutting edge and an optimization method thereof, and relates to the technical field of milling cutter design, and the optimization method comprises the following steps: determining a scale factor initial value based on a production target parameter, and adjusting the initial value in combination with a machining target material hardness value and a cutting process parameter, constructing a milling cutter model; establishing a plane-coordinate system at the center of a cutter head; determining the curvature of the star-shaped line according to a parameter equation of the single star-shaped line cutting edge containing the precise scale factor and an angle change parameter, and forming a plurality of star-shaped line cutting edges at different positions by rotating around the center of the cutter head by different angles. According to transition connection between the inner sharp corners of the star-shaped line cutting edges, transition connection between the adjacent star-shaped line cutting edges and transition connection between the star-shaped line cutting edges and the cylindrical face of the tool bit, optimization treatment is conducted through arcs, splines and spiral transition faces, load distribution is optimized in the cutting process, and vibration and abrasion are reduced.

The invention discloses an off-line terminal positioning method based on iridium orbit optimization, and belongs to the technical field of space-based opportunity signal positioning and low-orbit satellite navigation. The method comprises the following steps: firstly, receiving an iridium signal, extracting Doppler and pseudo-range observation values, and decoding to obtain a discrete orbit position sequence under an ECEF coordinate system; performing data preprocessing, including star number division, segmental arc segmentation, outlier elimination and coordinate conversion to an ECI system; fitting an orbit position through a four-order polynomial and deriving to obtain a speed, and constructing a weighted cost function to screen an optimal initial state; single-satellite decoupling, residual dimension reduction and LDLT decomposition acceleration solution are introduced, a damping factor is dynamically adjusted, and a broadcast orbit is optimized; taking the optimized state as an initial value, extrapolating an orbit based on a fourth-order perturbation gravity model with harmonic terms, and fusing Doppler and pseudo-range observation values to complete off-line terminal positioning. The method does not need to depend on real-time TLE data, and is fast in convergence and high in precision.