org.orekit.utils
Class EphemerisPvHermite

java.lang.Object
  org.orekit.utils.AbstractBoundedPVProvider
      org.orekit.utils.EphemerisPvHermite

All Implemented Interfaces:

PVCoordinatesProvider

public class EphemerisPvHermite
extends AbstractBoundedPVProvider

This class extends AbstractBoundedPVProvider which implements PVCoordinatesProvider and so provides a position velocity for a given date. The provided position velocity is based on a Hermite interpolation in a given position velocity ephemeris.

The interpolation extracts position, velocity and eventually acceleration from the ephemeris at the date just before and the date just after the interpolating date. Points extraction is based on an implementation of the ISearchIndex interface. This implementation should be based on a table of duration created from the date table with the duration = 0 at the first index.

Since:

3.1

Version:

$Id: EphemerisPvHermite.java 14756 2015-12-01 13:46:22Z bignon $

Author:

chabaudp

Concurrency :

not thread-safe

Concurrency comment :

internal mutable attributes

Field Summary

Fields inherited from class org.orekit.utils.AbstractBoundedPVProvider

tDate, tPVCoord

Constructor Summary

EphemerisPvHermite(PVCoordinates[] tabPV, Vector3D[] tabAcc, Frame frame, AbsoluteDate[] tabDate, ISearchIndex algo)
Creates an instance of EphemerisPvHermite.

EphemerisPvHermite(SpacecraftState[] tabState, Vector3D[] tabAcc, ISearchIndex algo)
Creates an instance of EphemerisPvHermite from a SpacecraftState table

Method Summary

AbsoluteDate	getMaxDate() For hermite interpolation, the last date is the date of the step before the last ephemeris point
AbsoluteDate	getMinDate() For hermite interpolation, the min date is the first ephemeris date which is also the reference date
PVCoordinates	getPVCoordinates(AbsoluteDate date, Frame frame) Get the PVCoordinates of the body in the selected frame.

Methods inherited from class org.orekit.utils.AbstractBoundedPVProvider

getDateRef, getFrame, getPreviousIndex, getSearchIndex, setPreviousIndex

Methods inherited from class java.lang.Object

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

Constructor Detail

EphemerisPvHermite

public EphemerisPvHermite(PVCoordinates[] tabPV,
                          Vector3D[] tabAcc,
                          Frame frame,
                          AbsoluteDate[] tabDate,
                          ISearchIndex algo)

Creates an instance of EphemerisPvHermite.

Parameters:

tabPV - position velocity coordinates table

tabAcc - acceleration table (can be null)

frame - coordinates expression frame

tabDate - table of dates for each position velocity

algo - class to find the nearest date index from a given date in the date table (If null, algo will be, by default, a BinarySearchIndexOpenClosed based on a table of duration since the first date of the dates table)

EphemerisPvHermite

public EphemerisPvHermite(SpacecraftState[] tabState,
                          Vector3D[] tabAcc,
                          ISearchIndex algo)

Creates an instance of EphemerisPvHermite from a SpacecraftState table

Parameters:

tabState - SpacecraftState table

tabAcc - Acceleration table (can be null)

algo - class to find the nearest date index from a given date (If null, algo will be BinarySearchIndexOpenClosed by default based on a table of duration since the first date of the dates table)

Throws:

IllegalArgumentException - spacecraftState table should contains elements, and if tabacc not null should be of the same size

Method Detail

getPVCoordinates

public PVCoordinates getPVCoordinates(AbsoluteDate date,
                                      Frame frame)
                               throws OrekitException

Get the PVCoordinates of the body in the selected frame.

Parameters:

date - current date

frame - the frame where to define the position

Returns:

position/velocity of the body (m and m/s)

Throws:

OrekitException - if position cannot be computed in given frame

getMinDate

public AbsoluteDate getMinDate()

For hermite interpolation, the min date is the first ephemeris date which is also the reference date

Specified by:

getMinDate in class AbstractBoundedPVProvider

Returns:

minimum ephemeris date

getMaxDate

public AbsoluteDate getMaxDate()

For hermite interpolation, the last date is the date of the step before the last ephemeris point

Specified by:

getMaxDate in class AbstractBoundedPVProvider

Returns:

maximum ephemeris date