Reading with Time Filtering

Time filtering provides a means to select data from specific time windows and/or select data that has a specific data interval. Within the Non-DSS Selector, time filtering is only applied when using the "Select File(s) Based on Specified Criteria" option. Alternatively, time filtering in the DSS Selector will trim the available records when using the "Selected Specific TINs" option, or functions similarly to the Non-DSS Selector when using the "Select File(s) Based on Specified Criteria" option.

Item	Description
1	If this is checked, any paths that match the path masks are further filtered by the time filtering criteria defined by items 15 through 18. For all paths that match the given path mask, the program applies the timespan criteria to the D and E parts of the pathname respecting the time zone settings as specified.
2	This specifies how to apply the time filter to the paths matching the given mask. When set to 'Start time only' the program inspects only the start time of the data. If it falls within the 'Start Date' and 'End Date' filters it will be included. When set to 'Exclusive' both the start times and end times of the data must occur within the given time filter. When set to 'Inclusive' either the start time or the end time must occur within the given time filter.
3	This is the time filter used to set the start and end times used to filter the file list. Either date can be specified in either an explicit or relative way. When the filter is specified as 'Explicit' as shown for the start date, an actual date is specified which does not change with the current time. When specified as 'Relative' as shown above for the end date, every time a search is done, a date is computed based on adding the specified timespan from the current time. If the timespan is negative as shown above, then the date computed would occur before the current date.
4	When 'Relative' is selected, two controls will be shown to specify a timespan which is added to the current time to compute a date. If it is negative it occurs before the current date. The dropdown box specifies whether the scalar is in Days, Hours, etc.
5	When 'Explicit; is selected, the time zone is displayed and matches the display time zone (defined for a session in the Properties Window using the Properties->Display Session Time Zone setting). All dates and times must be displayed using the session time zone.
6	Select this item if the duration of the TIN is known. Most often the duration is 1 hour or 24 hour. In the event it is not, elect 'Other' and pick a different supported duration from the list.

When using the time filters on the TIN selection dialog to select date ranges for inclusion/exclusion of data, the times can be specified as either 'Explicit' or 'Relative' for both Starting and Ending dates. These selections are used to adjust the times selected to move forward along with the change in time.

Start Date	End Date	Description
Explicit	Explicit	The dates and times are not adjusted. When the program determines which files/paths are included, these times will be as they were before and the image aggregation is as it was before. Note that if any new files/paths have become available they will be included in the final dataset.
Relative	Explicit	The start time is set to adjust but not the end time. It would be unusual to set the options this way. When the program determines which files/paths are included it would adjust the starting time based on the current time. Since the end time is fixed, the timespan would continue to get smaller and smaller until the start time became later than the end time and then no data would show up.
Explicit	Relative	Only the end time is adjusted for current time. This would be a common setting if, for example, a storm was being watched over several days. The storm start time does not change but every time the program reevaluates the timespan it adjusts the ending time to encompass an ever widening timespan. Note that if a map window had this option set and the static starting time was not manually modified then the list of images being aggregated would continue to grow larger unbounded.
Relative	Relative	Both times are adjusted for current time. This would be a common setting if, for example, one wished to always see the last 3 days of data aggregated together when the program reevaluated the time window.