Comm CommSystem AccessOptions
Set or modify access options for a CommSystem (Deprecated Command)
Syntax
Comm <CommSysObjectPath> CommSystem AccessOptions <Parameters>
This command is DEPRECATED and has been replaced by:
CommSystemDescription
This command was deprecated in STK 11, it should no longer be used. This command has been replaced by the CommSystem command.
Use the Comm CommSystem AccessOptions command to set or modify access options for a CommSystem. The CommSystemObject path points to the CommSystem object being updated.
CommSystem AccessOptions properties are initialized with values from Access Default preferences, available from the Edit menu->Preferences->Access Defaults. For these settings to take affect in a CommSystem, these preferences must be set before inserting a CommSystem object into a scenario. Any CommSystem object inserted before changing the settings will continue to inherit old settings. It must be deleted and re-added for new default values to take effect.
Light Time Delay access settings, such as Clock Host and Signal Sense, that are available for some STK objects are not available for a CommSystem because they are controlled by the transmitter and receiver objects in the CommSystem.
The following table describes the Light Time Delay, Event Detection, and Step Size Control parameters. Any or all parameters can be included on the command line.
| <Parameters> | Description |
|---|---|
| UseLightTimeDelay {Yes | No} | Use light time delay in access calculations. |
| LightTimeDelayConvergence <Value> | Sets the time tolerance used by the access algorithms for computing the light time delay between objects, when light time delay effects are considered. The light time delay is found whenever a correction to the previous estimate is within the time tolerance. <Value> is entered in Connect time units and must be between 1.0e-9 seconds and 0.1 seconds. |
| AberrationType {None | Annual | Total} | Sets the model of aberration to be used in access computations. None indicates that aberration is ignored; Annual indicates that only annual aberration is accounted for; Total indicates that the full aberration correction is to be applied. |
| EventsBasedOnSamples {On | Off} | Determines access intervals simply based on the samples without doing any extra sub-sampling. |
| TimeConvergence <Value> | Set the time tolerance used during event detection. Event times will be determined to within this specified tolerance. <Value> is entered in Connect Time units and must be greater than 1.0e-9 seconds. EventsBasedOnSamples must be set to Off for this value to have any effect. |
| RelValueConvergence <Value> | An event is said to be detected when a constraint value's relative difference compared to the previous sample is within this tolerance. <Value> must be between 0.0 and 1.0 EventsBasedOnSamples must be set to Off for this value to have any effect. |
| AbsValueConvergence <Value> | Set the criterion used for convergence for values near 0. <Value> must be between 1.0e-30 and 1.0e+30 EventsBasedOnSamples must be set to Off for this value to have any effect. |
| MaxTimeStep <Value> | Sets the maximum sampling step size used in access computations when computing the CommSystem. <Value> is entered in Connect Time units and must be between 1.0e-5 and 315576000.0 seconds. When this value is entered Step Size Control will be set to use a variable step to choose samples. |
| MinTimeStep <Value> | Sets the minimum sampling step size used in access computations when computing the CommSystem. <Value> is entered in Connect Time units and must be between 1.0e-5 and 315576000.0 seconds. When this value is entered Step Size Control will be set to use a variable step to choose samples. |
| FixedSampleStep <Value> | Enter a step size value to control the step size used in Access sampling. <Value> is entered in Connect time units and must be greater than 1.0e-5 seconds. When this value is entered, Step Size Control is set to use a fixed step to choose samples. |
| FixedStepTimeBound <Value> | Enter a value to control the alignment of samples with a UTC time grid. <Value> is entered in Connect time units and must be between 0.0 and 86400.0 seconds. When this value is entered, Step Size Control is set to use a fixed step to choose samples. |
Examples
To disable the light time delay option for the access visibility computations:
To set access visibility computations at fixed 10 second steps:
To ensure integrity of results, it is recommended that the step resolution be finer than the CommSystem compute step size and the data provider reporting step size.
To modify multiple options:
Return message
Group membership
This command belongs to the following group(s):
Version
11