12 results about "Ground track" patented technology

A satellite for software-defined satellite imagery includes an optical assembly. The satellite further includes an attitude control system. The attitude control system is configured to control an orientation of the satellite such that the optical assembly slews across a ground track of the satellite. The satellite further includes a set of image sensors configured to capture an image using light directed to the set of image sensors at least in part by the optical assembly.

The invention relates to a common ground trajectory giant constellation fly-over orbit optimization method, device and equipment, and relates to the technical field of spaceflight. The method comprises the steps of obtaining task initial parameters; establishing an orbit optimization model; traversing different fly-over initial moments of a first target satellite in the whole task to obtain a maneuver-free fly-over nominal orbit and a corresponding target satellite fly-over number; deriving a plurality of maneuver-free flyover orbits for accessing the whole constellation; establishing a multi-pulse transfer optimization model, and solving the optimal speed increment of each transfer type; mapping each maneuver-free flyover track into an access node, constructing a node transfer cost matrix according to the optimal speed increment, and solving an optimal access sequence for accessing all nodes; and integrating the parameters of a plurality of maneuver-free flyover orbits, the optimal access sequence and the maneuver scheme of each transfer type to form a most economical propellant flyover scheme for accessing the whole common ground trajectory giant constellation. According to the method, multiple target satellites can fly over through one-time maneuvering, and efficiency and fuel economy are both considered.

Methods and systems for providing voice, video, or data services using optimized ground track satellites and ground tracking antennas are disclosed herein. An example system includes first satellites in a first constellation, the first satellites having a first fixed ground track relative to Earth's surface, and an antenna being located at a location on the first fixed ground track, the antenna being configured to steer in a single axis to track the first satellites, wherein each of the first satellites reach the location, after an integer number of days that include a period of two or more sidereal days with an adjustment to account for nodal precession of the first satellites.

The application provides a method and device for maintaining a retrograde co-ground track constellation by applying tangential thrust, and relates to the technical field of constellation orbit dynamics and control. The method comprises the following steps: determining a first tangential thrust required by a first satellite in a predetermined constellation according to a correction value of a subsatellite point longitude drift of the first satellite, and applying the first tangential thrust to the first satellite, wherein the first tangential thrust is used for maintaining a retrograde co-ground track of the first satellite; and applying a second tangential thrust corresponding to a second satellite in the constellation to the second satellite to maintain a relative phase between the second satellite and the first satellite. The method provided by the embodiment of the application only needs to apply a tangential thrust to a satellite, does not need to apply an orbit normal thrust to the satellite, and can maintain a subsatellite point track of a retrograde co-ground track constellation in the constellation.

This invention provides a graph-theory-based method and apparatus for determining multi-angle observation opportunities in heterogeneous SAR, comprising: calculating the intersection points of the ground trajectory centerlines of several SAR satellites; establishing an edge on the ground trajectory centerlines connected by any two intersection points based on geometric constraints; for each intersection point, determining the neighboring intersection points based on the edge, obtaining interior angles based on the intersection point and its neighboring intersection points, and determining candidate cooperative points based on the interior angles; generating a local connectivity graph based on the candidate cooperative points, performing a heuristic search on the local connectivity graph according to preset rules to obtain polygonal regions; and verifying and filtering the polygonal regions to obtain cooperative observation areas. This scheme can proactively and completely identify geometrically feasible cooperative observation opportunities from a massive number of trajectory intersection points, providing a systematic solution for the efficient utilization of global on-orbit SAR resources.

The present invention is an autonomous mission planning method for near-circular orbit imaging satellites. The present invention relates to the fields of satellite bus management, attitude control, and orbit determination, and solves problems such as high consumption of manpower and material resources, cumbersome planning processes, and low utilization rate of satellite resources in existing ground-based planning methods. First, the present invention uses the ground track analysis method to delimit the satellite observation range and preliminarily screen out possible imaging points within the planning period; then estimates service parameters, and more accurately estimates the imaging side-sway angle, overpass time window, and payload configuration parameters that can cover the target points; finally, plans the optimal imaging scheme through a priority-based sequence filling algorithm. The on-board autonomous planning method described in the present invention does not require the consumption of a large amount of manpower and material resources, makes full use of satellite imaging resources, inputs the target library, the current position, velocity, and orbit information of the satellite, and the corresponding UTC time into the autonomous planning program, runs the autonomous planning method, and quickly and accurately completes the autonomous imaging mission planning for multiple target points.

Methods for a reusable space vehicle to land at substantially the same location as its launching site. The vehicle traveling in a particular orbit, which is a repeating ground track orbit, allows for launching and landing at the same location once per day. The repeating ground track orbits that allow for launching and landing at the same location once per day overfly the launch and landing site once per day. Launching and landing at the same site provides a number of direct advantages. For example, the just-landed vehicle may be transported a relatively short distance to the launch site, reconditioned relatively quickly, and be ready for a quick turn-around launch.

The utility model provides a medium and low orbit satellite ground tracking rotary table, which comprises an antenna body, a rotary table upright post, an X-axis box body and a Y-axis box body, and is characterized in that the X-axis box body is arranged at the top end of the rotary table upright post; a first central shaft and a second central shaft penetrate through the end faces of the X-axis box body and the Y-axis box body respectively, and the two ends of the first central shaft and the two ends of the second central shaft are rotationally matched with the X-axis supporting arm and the Y-axis supporting arm respectively; the Y-axis box body is fixed at the top end of the X-axis support arm; the antenna body is fixed at the top end of the Y-axis support arm; the X-axis box body drives the X-axis support arm to drive the Y-axis box body, the antenna body rotates around a first central shaft, and the Y-axis box body drives the Y-axis support arm to drive the antenna body to rotate around a second central shaft. According to the invention, the problem of overhead tracking of a tracking satellite is solved by using a two-axis orthogonal rotary table structure, and the installation of antenna bodies with different sizes can be realized by changing the counter weights of the X axis and the Y axis, the height of the rotary table stand column and the power of the motor.

The invention provides a method and device for maintaining a regression common ground trajectory constellation applying tangential thrust, and relates to the technical field of constellation orbit power and control. The method comprises the steps that first tangential thrust needed by a first satellite is determined according to a predetermined correction value of sub-satellite point longitude drift of the first satellite in a constellation, the first tangential thrust is applied to the first satellite, and the first tangential thrust is used for maintaining a regression common ground track of the first satellite; and applying a second tangential thrust corresponding to a second satellite except the first satellite in the constellation to maintain a relative phase between the second satellite and the first satellite. According to the method provided by the embodiment of the invention, only tangential thrust needs to be applied to the satellites, orbital normal thrust does not need to be applied to the satellites, and the sub-satellite point trajectory of the satellite regression common ground trajectory constellation in the constellation can be maintained.

The present application relates to a kind of optimization method of remote sensing satellite ground track distribution based on genetic algorithm, belong to the technical field of remote sensing satellite constellation networking design, solve how to meet the problem of the remote sensing requirement of specific area in prior art.Through obtaining the parameter information of remote sensing satellite to establish remote sensing satellite ground track distribution deployment scheme and determine deployment objective function and constraint condition;Based on this, the ground track deployment scheme of remote sensing satellite is solved using fast non-dominated genetic algorithm, and the optimal deployment scheme is obtained.The revisit time interval of distribution target in region is realized to be smaller, the coverage is larger, the image type is more, and the number of satellite needing ground track adjustment is less.

This invention provides a method and apparatus for planning multi-angle observation missions in a heterogeneous SAR constellation, comprising: acquiring the ground trajectory centerlines of each SAR satellite in the heterogeneous SAR constellation during the planning period, and determining the intersection points of the ground trajectory centerlines; filtering the intersection points to obtain candidate cooperative points that satisfy geometric constraints; generating a local connectivity graph based on the candidate cooperative points, and performing a heuristic search on the local connectivity graph according to preset rules to obtain the cooperative observation area; and performing multi-objective optimization of the cooperative observation area based on cooperative constraint requirements and the task to be observed to obtain the target observation area. This scheme achieves efficient utilization of heterogeneous SAR resources, and can actively search for effective multi-angle observation areas given satellite resources, thereby improving planning efficiency and observation quality.