Package org.orekit.time

Class GPSDate

java.lang.Object

org.orekit.time.GPSDate

All Implemented Interfaces:

Serializable, TimeStamped

public class GPSDate
extends Object
implements Serializable, TimeStamped

Container for date in GPS form.

Since:

9.3

Author:

Luc Maisonobe

See Also:

AbsoluteDate, Serialized Form

Constructor Summary

Constructors

Constructor	Description
GPSDate(int weekNumber, double milliInWeek)	Build an instance corresponding to a GPS date.
GPSDate(AbsoluteDate date)	Build an instance from an absolute date.

Method Summary

Modifier and Type	Method	Description
AbsoluteDate	getDate()	Get the date.
double	getMilliInWeek()	Get the number of milliseconds since week start.
static DateComponents	getRolloverReference()	Get the reference date ensuring continuity across GPS week rollover.
int	getWeekNumber()	Get the week number since GPS epoch.
static void	setRolloverReference(DateComponents reference)	Set a reference date for ensuring continuity across GPS week rollover.

Methods inherited from class java.lang.Object

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

Constructor Detail

GPSDate

public GPSDate(int weekNumber,
               double milliInWeek)

Build an instance corresponding to a GPS date.

GPS dates are provided as a week number starting at GPS epoch and as a number of milliseconds since week start.

Many interfaces provide only the 10 lower bits of the GPS week number, just as it comes from the GPS signal. In other words they use a week number modulo 1024. In order to cope with this, when the week number is smaller than 1024, this constructor assumes a modulo operation has been performed and it will fix the week number according to the reference date set up for handling rollover (see setRolloverReference(reference)). If the week number is 1024 or larger, it will be used without any correction.

Parameters:

weekNumber - week number, either absolute or modulo 1024

milliInWeek - number of milliseconds since week start

GPSDate

public GPSDate(AbsoluteDate date)

Build an instance from an absolute date.

Parameters:

date - absolute date to consider

Method Detail

setRolloverReference

public static void setRolloverReference(DateComponents reference)

Set a reference date for ensuring continuity across GPS week rollover.

Instance created using the GPSDate(weekNumber, milliInWeek) constructor and with a week number between 0 and 1024 after this method has been called will fix the week number to ensure they correspond to dates between reference - 512 weeks and reference + 512 weeks.

If this method is never called, a default reference date for rollover will be set using the date of the last known EOP entry retrieved from UT1 time scale.

Parameters:

reference - reference date for GPS week rollover

Since:

9.3.1

See Also:

getRolloverReference(), GPSDate(int, double)

getRolloverReference

public static DateComponents getRolloverReference()

Get the reference date ensuring continuity across GPS week rollover.

Returns:

reference reference date for GPS week rollover

Since:

9.3.1

See Also:

#setRolloverReference(AbsoluteDate), GPSDate(int, double)

getWeekNumber

public int getWeekNumber()

Get the week number since GPS epoch.

The week number returned here has been fixed for GPS week rollover, i.e. it may be larger than 1024.

Returns:

week number since GPS epoch

getMilliInWeek

public double getMilliInWeek()

Get the number of milliseconds since week start.

Returns:

number of milliseconds since week start

getDate

public AbsoluteDate getDate()

Get the date.

Specified by:

getDate in interface TimeStamped

Returns:

date attached to the object