Interactive graphics computer system for planning star-sensor-based satellite attitude maneuvers
First Claim
1. An interactive graphical attitude maneuver planning computer system for planning satellite attitude maneuvers comprising:
- a graphics display comprising at least a first window displaying a map of the celestial sphere as seen from a satellite and a second window displaying graphical slider bars for varying roll, pitch and yaw angles of the satellite, graphical. "RUN" and "STOP" buttons, and text entry windows for entering date and time;
a computer running an operating system supporting a windowing function responsive to user initiated events for executing functions to process events in an interactive manner, said computer system also running an application program on said operating system and windowing function to compute an attitude matrix, determine an orientation of at least one star sensor and compute sky and star sensor field of view displays; and
user input devices including a text entry device for entering date and time in said text entry windows and a pointing device for selecting and moving said graphical slider bars and selecting said "RUN" and "STOP" buttons, said windowing function responding to user inputs and interacting with said application program when said "RUN" button is selected to generate a display in said first window showing a movement of the star sensor across the sky and stars as they pass through the star sensor field of view providing the user with an immediate display of where the star sensor is pointing at any point in time of an orbit of the satellite.
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Accused Products
Abstract
Interactive graphical attitude maneuver planning computer system for planning satellite attitude maneuvers allows a user to immediately see where star trackers are pointing when the attitude and orbital position of a satellite are varied on the computer system. The computer system includes a graphics display on which the celestial sphere, centered at the satellite rather than the Earth, is projected. The horizontal axis of the display measures the Right Ascension angle, while the vertical axis measures the Declination angle. The display shows, in addition to stars, the region of the sky occluded by the Earth and interference regions around the moon, sun and planets, in which the star trackers should not point, and the fields of view of the star trackers. The attitude of the satellite is adjusted by means of graphical slider bars which vary the roll, pitch and yaw angle rotations. As the slider bars are adjusted, the star trackers move across the sky, and the stars pass through their fields of view, making it immediately obvious to the user where the star trackers are pointing, whether or not they will detect certain stars, and whether or not they will point too closely to the Earth, moon, sun, or planets.
153 Citations
12 Claims
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1. An interactive graphical attitude maneuver planning computer system for planning satellite attitude maneuvers comprising:
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a graphics display comprising at least a first window displaying a map of the celestial sphere as seen from a satellite and a second window displaying graphical slider bars for varying roll, pitch and yaw angles of the satellite, graphical. "RUN" and "STOP" buttons, and text entry windows for entering date and time; a computer running an operating system supporting a windowing function responsive to user initiated events for executing functions to process events in an interactive manner, said computer system also running an application program on said operating system and windowing function to compute an attitude matrix, determine an orientation of at least one star sensor and compute sky and star sensor field of view displays; and user input devices including a text entry device for entering date and time in said text entry windows and a pointing device for selecting and moving said graphical slider bars and selecting said "RUN" and "STOP" buttons, said windowing function responding to user inputs and interacting with said application program when said "RUN" button is selected to generate a display in said first window showing a movement of the star sensor across the sky and stars as they pass through the star sensor field of view providing the user with an immediate display of where the star sensor is pointing at any point in time of an orbit of the satellite. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A computer interactive method of displaying satellite attitudes to facilitate planning satellite attitude maneuvers comprising the steps of:
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generating a first window on a computer display screen in which a map of the celestial sphere as seen from a satellite is displayed, wherein the horizontal (x) axis of the display measures the Right Ascension angle and the vertical (y) axis measures the Declination angle and the celestial sphere is computed in an Orbit Normal coordinate frame in which the plane of the satellite'"'"'s orbit is the same as the x-y plane of the celestial sphere and the field of view of a star sensor on the satellite is displayed moving horizontally across the graphics display; generating a second window on the computer display screen in which graphical slider bars for varying roll, pitch and yaw angles of the satellite, graphical "RUN" and "STOP" buttons, and text entry fields for date and time entry are displayed; providing a user with a pointing device for selecting said graphical slider bars and a "RUN" button displayed in said second window, and for selecting stars displayed in said first window and a third window; providing the user with a text entry device for entering date and time in said text entry fields; responding to movement of a slider bar by the user using said pointing device by reading roll, pitch and yaw angles from the graphical slider bars, computing an attitude matrix and star sensor orientations, and displaying sky and star sensor fields of view in said first window; and responding to an input of date and time by the user making text entries in said text entry fields with said text entry device and a press of the "RUN" button by the user using said pointing device by adding a time step value to a current date and time, calculating positions of sun, moon and planets based on current date and time, calculating position and velocity of the satellite, computing an attitude matrix and star sensor orientations, and displaying sky and stars in said first window as they pass through the star sensor field of view providing the user with an immediate display of where the star sensor is pointing at any point in time of an orbit of the satellite. - View Dependent Claims (9, 10, 11, 12)
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Specification