org.orekit.rugged.utils

Class RoughVisibilityEstimator

java.lang.Object

org.orekit.rugged.utils.RoughVisibilityEstimator

public class RoughVisibilityEstimator
extends Object

Class estimating very roughly when a point may be visible from spacecraft.

The class only uses spacecraft position to compute a very rough sub-satellite point. It assumes the position-velocities are regular enough and without holes. It is intended only only has a quick estimation in order to set up search boundaries in inverse location.

Author:

Luc Maisonobe

See Also:

Rugged.dateLocation(String, org.orekit.bodies.GeodeticPoint, int, int), Rugged.dateLocation(String, double, double, int, int), Rugged.inverseLocation(String, org.orekit.bodies.GeodeticPoint, int, int), Rugged.inverseLocation(String, double, double, int, int)

Constructor Summary

Constructors

Constructor and Description
RoughVisibilityEstimator(OneAxisEllipsoid ellipsoid, Frame frame, List<TimeStampedPVCoordinates> positionsVelocities) Simple constructor.

Method Summary

Methods

Modifier and Type	Method and Description
AbsoluteDate	estimateVisibility(GeodeticPoint groundPoint) Estimate very roughly when spacecraft comes close to a ground point.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RoughVisibilityEstimator

public RoughVisibilityEstimator(OneAxisEllipsoid ellipsoid,
                        Frame frame,
                        List<TimeStampedPVCoordinates> positionsVelocities)
                         throws OrekitException

Simple constructor.

Parameters:

ellipsoid - ground ellipsoid

frame - frame in which position and velocity are defined (may be inertial or body frame)

positionsVelocities - satellite position and velocity (m and m/s in specified frame)

Throws:

OrekitException - if position-velocity cannot be converted to body frame

Method Detail

estimateVisibility

public AbsoluteDate estimateVisibility(GeodeticPoint groundPoint)

Estimate very roughly when spacecraft comes close to a ground point.

Parameters:

groundPoint - ground point to check

Returns:

rough date at which spacecraft comes close to ground point (never null, but may be really far from reality if ground point is away from trajectory)