Introduction | Time Tool | Vector Geometry Tool | Calculation Tool | Spatial Analysis Tool
STK Analysis Workbench Tools
Time Tool
The Time Tool includes components of the following basic types:
| Time Tool Components | ||
|---|---|---|
| Icon | Name | Description |
|
Time Instant | Defines components that produce a single moment in time. |
|
Interval | Defines components that produce a single interval of time. |
|
Interval List | Defines components that produce ordered lists of time intervals. |
|
Collection of Interval Lists | Defines components that produce a collection of related interval lists. |
|
Time Array | Defines components that produce intervals of time within which there are ordered arrays of times. |
All of these components deal with time related quantities. Time is fundamental to most computations in STK and is used in reporting and graphing as well as in static and dynamic visualizations.
Time components can be added to the Timeline View which provides a new way to display and operate on time components. They can be added via the Timeline View menus or dragged and dropped into the Timeline View from the Analysis Workbench window.
There are also new UI controls for entering time instances and time intervals throughout STK.
The basic types included in Time Tool correspond to different uses of time in STK. They also provide new capabilities by allowing you to extend and customize time-dependent computations and generate new types of output data.
Time Component Types
Shared Properties | Instants| Intervals | Interval Lists | Collection of Interval Lists | Arrays
The Time Component Add/Edit windows let you specify various properties of a component that you have added or selected for modification.
Shared Component Properties
STK Analysis Workbench components share a number of properties as listed below that can be accessed when adding or modifying components.
| Component Properties | |
|---|---|
| Option | Description |
| Type | Use the Select... button to display the list of available component types. |
| Name | Displays the name of the selected component or allows the naming of a newly created component. When naming new components spaces will be replaced with an underscore and invalid characters will be replaced with a hyphen. |
| Parent | Displays the component's parent object. Use the Select... button to change or select the component's parent object. |
| Description | An editable field which you may add descriptive text to. |
| Type Description | A read-only field that contains a short description of the component type. |
Defining Time Instants
The Time Instant type defines components that produce a single moment in time. For example, the following Time Instant components are available from the scenario:
- Today, NoonToday, Tomorrow, NoonTomorrow, J2000
See Time Keywords on STK Time for a discussion of the date constants Today, NoonToday, Tomorrow, and NoonTomorrow.
In addition, any component of Interval type also defines its start and stop time instants as subcomponents. For example, the Time Interval EphemerisTimeSpan, owned by a satellite, makes both the beginning and end of its interval available as Time Instants:
- EphemerisTimeSpan.Start, EphemerisTimeSpan.Stop
The following types of Time Instant components are available:
| Type | Description |
|---|---|
| Fixed Epoch | A time instant fixed to a specific date. |
| Fixed Time Offset | A time instant offset by a fixed time relative to another Time Instant component. |
| Signaled | A time instant defined by transmitting or receiving time from another Time Instant component between two specified locations (coordinate points from Vector Geometry Tool). |
| Start-Stop Time | The start or stop instant of a specified Time Interval component. |
| Time of Extremum |
The time of global minimum or maximum of a specified scalar calculation. Advanced Options... include settings for sampling and convergence, type of integration, and interpolation as well as the overall interval of integration specified by an Interval List component from the Time Tool. |
Defining Time Intervals
The Interval type defines components that produce a single interval of time. For example, the following Interval components are available for Satellite objects:
- EphemerisTimeSpan, AvailabilityTimeSpan
In addition, any component of Interval List type may also define various components of Interval type as sub-components.
The following types of Interval components are available:
| Type | Description |
|---|---|
| Between Time Instants | An interval with start and stop times defined by two specified Time Instant components. |
| Fixed Duration | An interval of fixed duration anchored at a time defined by a specified Time Instant component. |
| Fixed Interval | An interval with start and stop times specified as dates. |
| Fixed Time Offset | An interval offset by a fixed time relative to another Time Interval component. |
| Interval From List | A single interval created from an interval list defined by a specified Time
Interval List component using one of several selection strategies below:
|
| Offset from Time Instant | Offset from Time Instant where a specified before-time is subtracted from the time instant, and a specified after-time is added to the time instant, resulting in an interval. |
| Scaled |
An interval scaled up or down from another interval specified by a Time Interval component using either a relative percentage scale or an absolute duration scale. The absolute increment option extends the start and stop times of intervals by half of the specified increment so that the interval midpoint remains the same but its duration is extended by the specified increment. The relative increment computes an absolute increment as a specified fraction of the original interval duration and then applies it in the same way as the absolute increment option. |
| Signaled | An interval defined by a transmitting or receiving interval from another Time Interval component between two specified locations (coordinate points from Vector Geometry Tool). |
Defining Time Interval Lists
The Interval List type defines components that produce an ordered list of time intervals. For example, the following Interval List components are available for Satellite objects:
- PassIntervals
In addition, any component of Interval List type may also define various components of Interval type as sub-components. These include generically available Interval components such as Span, Longest and Shortest. These can vary in number and naming depending on the Interval List component from which they are generated.
The following types of Interval List components are available:
| Type | Description |
|---|---|
| File | Intervals loaded from a specified intervals file (*.int). |
| Filtered | An interval list created from a reference Interval List component by filtering certain intervals out. The filtering operations include selecting a certain number of first or last intervals, selecting intervals of at least/most certain duration, merging intervals unless they are separated by gaps of at least/most certain duration, selecting intervals if a certain side condition is satisfied at least/most certain duration or at least/most certain percentage of the time. The side condition is represented by a component of Condition type from the Calculation tool. |
| Fixed Interval List | Interval list containing intervals with fixed start and stop times. |
| Fixed Time Offset | Intervals offset by a fixed time relative to another Time Interval List component. |
| Merged | Intervals merged from multiple Interval or Interval List Time
Components using one of several merging operations:
The Minus operation is available when there are only two Time Components in the merge list. |
| Offset from Time Array | Offset from an array where a specified before-time is subtracted from each time in the array, and a specified after-time is added to each time in the array, resulting in a list of intervals. |
| Satisfaction |
Computes intervals of satisfaction of a specified condition. Advanced Options... include settings for sampling and convergence, type of integration, and interpolation as well as the overall interval of integration specified by an Interval List component from the Time Tool. |
| Scaled |
An interval list scaled up or down from another interval list specified by a Time Interval List component using either a relative percentage scale or an absolute duration scale. The absolute increment option extends the start and stop times of intervals by half of the specified increment so that the interval midpoint remains the same but its duration is extended by the specified increment. The relative increment computes an absolute increment as a specified fraction of the original interval duration and then applies it in the same way as the absolute increment option. |
| Signaled | An interval list defined by a transmitting or receiving interval list from another Time Interval List component between two specified locations (coordinate points from Vector Geometry Tool). |
Defining Time Interval Collections
The Time Interval Collection type defines components that produce a collection of related interval lists. For example, the following Interval List components are available for Satellite objects:
- LightingIntervals
Any component of Collection of Interval List type may also define various components of Interval List type as sub-components. For example, LightingIntervals component includes Sunlight, Umbra and Penumbra Interval List components as its sub-components.
If you add an interval list collection to an STK object's 2D Graphics Attributes, and then add individual lists from a previously added collection, you may see some graphics inconsistencies.
The following types of Collection of Interval Lists components are available:
| Type | Description |
|---|---|
| Field-of-View Obscuration | A collection of interval lists representing intervals of obstruction of a sensor's field of view. The interval lists are:
|
| Lighting | A collection of three interval lists, one for sunlight, one for penumbra and one for umbra condition for a trajectory of a specified point (coordinate point from Vector Geometry Tool). |
| Satisfaction |
A collection of interval lists containing intervals during which the condition set is satisfied. Advanced Options... include settings for sampling and convergence, type of integration, and interpolation as well as the overall interval of integration specified by an Interval List component from the Time Tool. |
| Signaled | A collection of interval lists defined by a transmitting or receiving collection from another Time Interval Collection component between two specified locations (coordinate points from Vector Geometry Tool). |
Defining Time Arrays
The Time Array type defines components that produce intervals of time within which there are ordered arrays of times. The times may or may not be evenly spaced. For example, the following Time Array components are available for Satellite objects:
- EphemerisTimes
The following types of Time Array components are available:
| Type | Description |
|---|---|
| Filtered |
Filters out certain times from the original Time Array component. The following options are available:
There is also an option to ensure that the end points of each interval are included when the Skip Time Step or Skip Count option is selected. |
| Fixed Step | Defines times separated by a specified fixed step. Times are placed within intervals of a specified Interval List component. The time steps can be anchored to the start/stop of the overall interval list, or to the start/stop of every interval within that interval list, or to a time specified by an additional Time Instant component. |
| Fixed Times | Defines a time array with explicitly specified times. Imported time components can be Time Instant, Interval, Interval List or Time Array. If an Interval or Interval List is imported then the start time of each interval will be added to the Fixed Times time array. |
| Merged | Combines multiple constituent arrays or time instants using one of several merging operations:
The Minus operation is available when there are only two components in the combined list. |
| Signaled | Signaling an array of times from one location to another using specified signal transmission characteristics. The original array of times is determined by a Time Array component, the two locations are specified using Point components from the Vector Geometry Tool, and the signal transmission characteristics include signal sense – Transmit or Receive, transmission speed time delay convergence and a reference system in which the signal path is defined. |
| Start-Stop Times | Defines a time array based on start, stop or both times from every interval within an interval list from a specified Interval List component. |
| Times of Condition Crossings |
Times at which a specified Condition component from the Calculation tool changes its status from satisfied to unsatisfied, or vice versa, or both. Additional options include settings for sampling and convergence as well as settings of the overall time limits defined by an Interval List component. Advanced Options... include settings for sampling and convergence, type of integration, and interpolation as well as the overall interval of integration specified by an Interval List component from the Time Tool. |
| Times of Extrema |
Times at which a specified Scalar calculation component from the Calculation tool reaches its local maximums, minimums or both. Additional options include settings for sampling and convergence as well as settings of the overall time limits defined by an Interval List component. Advanced Options... include settings for sampling and convergence, type of integration, and interpolation as well as the overall interval of integration specified by an Interval List component from the Time Tool. |
| Times of Parameter Set Samples | Contains times that provide an adequate sampling of the specified parameter set. |