Apparatus and method for controlling a satellite
AssigneeKorea Aerospace Research Institute
InventorsMoon Jin Jeon, Sang Rok Lee, Hui Kyung Kim, Eung Hyun Kim, Seong Bin Lim, Seok Weon Choi
Life of this patent
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Abstract
Provided is an apparatus for controlling an orbiting satellite by sensing a change in a yaw angle of the orbiting satellite and calculating a ground sample distance (GSD) based on the yaw angle. The apparatus may include a sensor configured to sense a yaw angle corresponding to yaw steering of the orbiting satellite, and a processor configured to calculate, based on the yaw angle, a GSD corresponding to a length of a pixel projected onto a planetary surface scanned by the orbiting satellite.
Claims17
An orbiting satellite comprising:
- a movement controller configured to control an attitude of the orbiting satellite, the attitude comprising an orbital velocity, a roll angle, a pitch angle and a yaw angle of the orbiting satellite;
- an image acquirer configured to scan a planetary surface in a scanning direction corresponding to the attitude;
- and
- a calculator:
- wherein the calculator is configured to:
- calculate a major axis and a minor axis of an ellipse corresponding to a trace of a pixel projected onto the planetary surface based on a change in the yaw angle;
- calculate a tilt angle between a direction vector and a line of sight (LOS) vector projected onto the planetary surface;
- and
- calculate a ground sample distance (GSD) according to the following equation:
- GSD=√{square root over (a2 cos (ψ+β)2+b2 sin (ψ+β)2)}
- wherein:
- a is a length of the major axis;
- ψ is the yaw angle;
- β is the calculated tilt angle;
- and
- b is a length of the minor axis.
A method of calculating a line rate corresponding to a scanning direction of an orbiting satellite, the method comprising:
- sensing an attitude of the orbiting satellite, the attitude comprising a roll angle, a pitch angle and a yaw angle of the orbiting satellite;
- calculating a major axis and a minor axis of an ellipse corresponding to a trace of a pixel projected onto a planetary surface of a planet being scanned by the orbiting satellite based on a change in the yaw angle;
- calculating a tilt angle between a scanning direction vector and a line of sight (LOS) vector projected onto the planetary surface;
- and
- calculating a ground sample distance (GSD) according to the following equation:
- GSD=√{square root over (a2 cos (ψ+β)2+b2 sin (ψ+β)2)}
- wherein:
- a is a length of the major axis;
- ψ is the yaw angle;
- β is the calculated tilt angle;
- and
- b is a length of the minor axis.
A non-transitory computer-readable storage medium storing a program for causing a processor to perform a method of calculating a line rate corresponding to a scanning direction of an orbiting satellite, the program comprising:
- a set of instructions to calculate a major axis and a minor axis of an ellipse corresponding to a trace of a pixel projected onto a planetary surface scanned by the orbiting satellite based on a change in a yaw angle of the orbiting satellite;
- and
- a set of instructions to calculate a tilt angle between a scanning direction vector and a line of sight (LOS) vector projected onto the planetary surface;
- and
- a set of instructions to calculate a ground sample distance (GSD) according to the following equation:
- GSD=√{square root over (a2 cos (ψ+β)2+b2 sin (ψ+β)2)}
- wherein:
- a is a length of the major axis;
- ψ is the yaw angle;
- β is the calculated tilt angle;
- and
- b is a length of the minor axis.
Dependencies are inferred from the claim text.