org.orekit.time
Class LocalTime

java.lang.Object
  org.orekit.time.LocalTime

public class LocalTime
extends Object

This class provides methods to compute local time (true local time and mean local time).

The local time is represented by the angle between the projections of the Sun and the satellite in the equatorial plane; therefore this angle is equal to zero when the local time is 12.00h and Π when the local time is 0.00h.

Since:

3.0

Version:

$Id: LocalTime.java 16806 2016-10-17 16:11:33Z bignon $

Author:

Emmanuel Bignon

Concurrency :

not thread-safe

Constructor Summary

LocalTime(PVCoordinatesProvider sunEphemeris)
Constructor

Method Summary

double	computeEquationOfTime(AbsoluteDate date) Compute equation of time in TIRF in the range ]-43200s; 43200s].
double	computeMeanLocalTime(AbsoluteDate date, Vector3D pos, Frame frame) Compute mean local time in TIRF frame in s.
double	computeMeanLocalTime(Orbit orbit) Compute mean local time in TIRF frame in s.
double	computeTrueLocalTime(AbsoluteDate date, Vector3D pos, Frame frame) Compute true local time in TIRF frame in the range [0s; 86400s[.
double	computeTrueLocalTime(Orbit orbit) Compute true local time in TIRF frame in the range [0s; 86400s[.

Methods inherited from class java.lang.Object

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

Constructor Detail

LocalTime

public LocalTime(PVCoordinatesProvider sunEphemeris)

Constructor

Parameters:

sunEphemeris - Sun ephemeris

Method Detail

computeTrueLocalTime

public double computeTrueLocalTime(AbsoluteDate date,
                                   Vector3D pos,
                                   Frame frame)
                            throws OrekitException

Compute true local time in TIRF frame in the range [0s; 86400s[.

Parameters:

date - date

pos - position in provided frame frame

frame - frame in which position is defined

Returns:

true local time in TIRF frame (in s)

Throws:

OrekitException - thrown if Sun PV coordinates could not be retrieved

computeTrueLocalTime

public double computeTrueLocalTime(Orbit orbit)
                            throws OrekitException

Compute true local time in TIRF frame in the range [0s; 86400s[.

Parameters:

orbit - orbit

Returns:

true local time in TIRF frame (in s)

Throws:

OrekitException - thrown if Sun PV coordinates could not be retrieved

computeMeanLocalTime

public double computeMeanLocalTime(AbsoluteDate date,
                                   Vector3D pos,
                                   Frame frame)
                            throws OrekitException

Compute mean local time in TIRF frame in s.

Mean local time is equal to true local time minus equation of time.

Parameters:

date - date

pos - position in provided frame

frame - frame in which position is defined

Returns:

mean local time in TIRF frame (in s)

Throws:

OrekitException - thrown if true local time could not be computed

computeMeanLocalTime

public double computeMeanLocalTime(Orbit orbit)
                            throws OrekitException

Compute mean local time in TIRF frame in s.

Mean local time is equal to true local time minus equation of time.

Parameters:

orbit - orbit

Returns:

true local time in TIRF frame (in s)

Throws:

OrekitException - thrown if Sun PV coordinates could not be retrieved

computeEquationOfTime

public double computeEquationOfTime(AbsoluteDate date)
                             throws OrekitException

Compute equation of time in TIRF in the range ]-43200s; 43200s].

Parameters:

date - date

Returns:

equation of time in TIRF frame (in s)

Throws:

OrekitException - thrown if equation of time could not be computed