Default Times

The DefaultTimes attribute is used to control start and stop times for OD processes and the length of intervals used in those processes.

DefaultTimes Options
Scope	Option	Description
Processes	StartMode	Select between: EarliestSatEpoch (default) StartTime
	StartTime	Available if StartMode is set to StartTime.
	StopMode	Select between: StopTime TimeSpan
	StopTime	Available if StopMode is set to StopTime.
	TimeSpan	Available if StopMode is set to TimeSpan. Default is 24 hrs.
Intervals	TimeSpan	Default is 4 hrs.

Determination of Start and Stop Times for Newly Created Objects

Start and stop times to be used in the scenario are calculated as follows. If the StartMode is StartTime, then the value of the StartTime attribute will be the start time. If the StartMode is EarliestSatEpoch, then the start time will be the earliest epoch of all satellites in the scenario. If there are no satellites in the scenario, then the StartTime attribute value is used.

If the StopMode is StopTime, and the value of the StopTime attribute is greater than the calculated start time, then the StopTime attribute value will be the stop time. Otherwise, the stop time is the calculated start time plus the TimeSpan.

Use of Start and Stop Times by Newly Created Objects

The following rules control the use of start and stop times by newly created OD objects:

Use of Start and Stop Times by Newly Created OD Objects
Object	Use of Start and Stop Times
Satellite	When you create a satellite, the satellite epoch will be set to the scenario start time. Also the EphemerisGeneration.StartTime is set to the scenario start time (or satellite epoch), and the EphemerisGeneration.Span is calculated as the difference between the scenario start time (or satellite epoch) and scenario stop time.
Filter	When you add a new filter, the start and stop times are based on the scenario start and stop times, as are the default smoother data start and stop times.
Simulator	A new simulator sets its start and stop times on the basis of the scenario settings. In addition, when you add an entry to the CustomTrackingInterval’s Schedule list, the first interval added to either the inclusion interval or the exclusion interval has a default interval span based on the scenario’s DefaultTimes.Intervals.TimeSpan attribute.
Smoother	A new smoother sets its start and stop times on the basis of the scenario’s stop and start times, respectively.
GNSSConstellation	If you want to override the source file times, the NewStartTime will be set to the scenario start time.
LeastSquares	When you add a new stage to a Least Squares object, the default LS fit time span will be set on the basis of the scenario’s DefaultTimes.Intervals.TimeSpan attribute.
GNSSReceiver	Clock epoch depends on the object to which the GNSSReceiver object is attached: When added to a facility, the clock epoch is set to the scenario start time. When added to a satellite, the clock epoch is set to the satellite epoch.

Use of Start Time and Time Span by Custom Data Editing Schedule Intervals

The following rules apply to the use of start time and time span when adding new intervals to the Custom Data Editing schedule:

Use of Start Time and Time Span by Custom Data Editing Schedule Intervals
Object	Use of Start Time and Time Span
Scenario	When you first add an interval to the Scenario Measurements.ViewAndSave.CustomDataEditing.Schedule, the interval start time will default to the scenario start time. The interval stop time will be the scenario start time plus the default Intervals.TimeSpan.
LeastSquares	When you first add an interval to any Least Squares CustomDataEditing.Schedule, the interval start time will default to the scenario start time. The interval stop time will be the scenario start time plus the default Intervals.TimeSpan.
Filter	When you first add an interval to any Filter CustomDataEditing.Schedule, the interval start time will default to the most recently set start time or restart time of any filter object. The interval stop time will be the interval start time plus the default Intervals.TimeSpan.