Class AlongTrackAiming
- java.lang.Object
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- org.orekit.models.earth.tessellation.AlongTrackAiming
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- All Implemented Interfaces:
TileAiming
public class AlongTrackAiming extends Object implements TileAiming
Class used to orient tiles along an orbit track.- Author:
- Luc Maisonobe
- See Also:
ConstantAzimuthAiming
,DivertedSingularityAiming
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Constructor Summary
Constructors Constructor Description AlongTrackAiming(OneAxisEllipsoid ellipsoid, Orbit orbit, boolean isAscending)
Simple constructor.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description Vector3D
alongTileDirection(Vector3D point, GeodeticPoint gp)
Find the along tile direction for tessellation at specified point.List<GeodeticPoint>
getSingularPoints()
Get points at which aiming direction cannot be computed.
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Constructor Detail
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AlongTrackAiming
public AlongTrackAiming(OneAxisEllipsoid ellipsoid, Orbit orbit, boolean isAscending)
Simple constructor.- Parameters:
ellipsoid
- ellipsoid body on which the zone is definedorbit
- orbit along which tiles should be alignedisAscending
- indicator for zone tiling with respect to ascending or descending orbits
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Method Detail
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getSingularPoints
public List<GeodeticPoint> getSingularPoints()
Get points at which aiming direction cannot be computed.As per Brouwer's hairy ball theorem, any vector field on the 2-sphere has at least one zero. This implies that any implementation of this interface has at least one point where the aiming direction cannot be computed. The most typical example is aiming always towards North pole, for which both poles are singular points.
- Specified by:
getSingularPoints
in interfaceTileAiming
- Returns:
- a non-empty (as per hairy ball theorem) list of points where aiming direction is either zero or cannot be computed
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alongTileDirection
public Vector3D alongTileDirection(Vector3D point, GeodeticPoint gp)
Find the along tile direction for tessellation at specified point.- Specified by:
alongTileDirection
in interfaceTileAiming
- Parameters:
point
- point on the ellipsoid (Cartesian coordinates)gp
- point on the ellipsoid (geodetic coordinates)- Returns:
- normalized along tile direction
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