In addition to the new features, this release of the Ansys Systems Tool Kit® (STK®) application also provides technical corrections from the last release. Click the capability in the table below to jump to the corresponding release notes section.
| Release Notes by Capability | ||
|---|---|---|
| Access | Analysis Workbench | Analyzer |
| Astrogator | Aviator | Chains |
| CommRad | Coverage | EOIR |
| RF Channel Modeler | STK Engine on Linux | STK general |
| Test and Evaluation Tool Kit | ||
Access
The STK Access capability determines when one object can see another object, given any applied constraints. In the STK v13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| ANLY-11 | The Active Constraints Data Provider now provides additional data elements that were previously only provided by the All Contraints Data Provider (e.g., Dimension, Min, and Max settings for MinMax constraints, etc.). For a full listing, see "Active Constraints" in the Data Provider help. |
| ANLY-22 | Reporting of values from Access' ConstrainData data provider improved in cases where the constraint applies to a linked object, such as a linked Antenna used by a Transmitter or Receiver. Previously, values might not have been computed at all, leaving the column of values blank. |
| ANLY-873 | The LLA Grazing Point and LLR Grazing Point data providers, available from Access, now compute the grazing point consistent with the GrazingAlt and GrazingAngle constraints. Previously, if Access considered aberration, such as between a satellite and a star, the GrazingAlt and GrazingAngle constraints would use the direction to the star considering aberration, while the data providers would ignore aberration. |
| ANLY-874 | The line-of-sight algorithm for access to stars now produces the precise direction of light motion. Previously, slight imprecisions between newly computes access times and old values differed depending on how fast the other object moved. Fast-moving satellites were able to make up the error quickly (in seconds), but relatively slow-moving vehicles close to the ground might have taken minutes to make up the error, causing large access time differences. |
| ANLY-885 | The accuracy of access computations is improved for targeted sensors by better capturing pointing direction discontinuities caused by target objects undergoing large differences in their motion direction. |
| ANLY-900 | Access computations have improved for Aircraft, Ground Vehicle, and Ship vehicle objects that use STK External ephemeris files. Computation time is now shorter for files that contain tens of thousands of points. Accuracy has improved for files for which you set the SmoothData flag to Yes, indicating that the motion is smooth, and the vehicle performs high-frequency motions, such as fast turns. |
| PLAT-1847 | You can no longer add LocalTime, ApparentTime, Intervals, and Duration constraints to a single object two or more times via the Object Model. |
| PLAT-40613 | The constraint value for the Elevation Angle and Line Of Sight constraints for an Area Target object, reported through the Access Constraint Data data provider, now correctly reports the elevation angle from the Area Target, not the trending metric used for computing the access intervals. The trending metric enhances finding access visibility intervals by combining the computed elevation angle with other metric data, a distance metric representing the closest distance to the boundary from the subpoint of the Area Target object, but the STK application should not report it by the Access Constraint Data data provider, which should rather report the constraint value itself. |
Analysis Workbench
The STK Analysis Workbench capability (AWB) comprises four application-wide tools that you can use to create custom components for your scenarios. In the STK v13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| ANLY-903 | The computational speed of the Function(x) Calculation Scalar has been improved by avoiding excessive oversampling when trying to determine its available times (i.e., the time intervals where the scalar can provide a value). The availability intervals are computed whenever the underlying function has a discontinuity or limitation in its domain, such as Sqrt() and Log(), which can only be evaluated when its argument is nonegative. Exp() can only be evaluated if the argument is not excessively large or small. |
Analyzer
The STK Analyzer capability blends the engineering analysis capabilities of the Ansys ModelCenter® application with the STK application. In the STK 13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| ANLZR-913 | Relative directory paths are now working properly when using the Model Center plugin. |
| ANLZR-914 | The availability stop time was being converted to a string, causing the last few decimal places to be dropped. This caused STK software to report that there was no data availabile. This no longer occurs. |
| ANLZR-964 | The Design of Experiments tool no longer resizes the Analyzer window on 4K displays. |
| ANLZR-971 | For SatelliteCollection / Walker, you no longer get an error during trade studies if the shell name has the word "Shell" in it. |
| ANLZR-976 | If Analyzer cannot find the STK scenario, the Model Center plugin now enables you to select an updated location for the scenario. |
| ANLZR-984 | Graphics updates no longer fail when using the Model Center plugin. |
| ANLZR-986 | SatelliteCollection / Walker no longer resets SatellitesInPlane to zero. |
Astrogator
The STK/Astrogator® capability contains specialized analysis computations for interactive orbit maneuvering and spacecraft trajectory design. In the STK v13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| GATOR-3 | With the exception of the AsteroidTemplate central body, you can no longer duplicate any central bodies in the Component Browser. |
| GATOR-128 | In previous versions of the STK Astrogator capability, the Incoming Asymptote RA of the Target Vector Incoming Asymptote coordinate system was off by 180 degrees from the incoming asymptote v-infinity vector. This issue has been resolved, but there are breaking changes when you load older scenarios. Carefully inspect any Target Sequence profile that uses Incoming Asymptote RA as either a control or as a result. |
| GATOR-158 | The Astrogator capability will no longer run indefinitely when an Astrogator satellite with a large number of segments is loaded into a scenario and the satellite is rerun in such a way that far fewer segments are generated. |
| GATOR-3435 | You can no longer select "Override Segment Settings" on the Radiation Pressure propagator function in the Component Browser. This deprecated functionality has been removed. |
| GATOR-3490 | Two low-fidelity integrators (RK4 Adapt and RK23) are no longer available as choices for use by propagators. |
| GATOR-3517 | The reporting of the time past ascending node in the MCS Summary report has been improved by reporting a value of 0 if the state is on the ascending node, rather than reporting the negative of one full period. While both are technically correct, the zero value is considered more informative. |
| GATOR-3577 | The Elliptical Restricted Three-body Problem (ER3BP) functionality is no longer available. |
| GATOR-3583 | Analysis Workbench components are now properly notified when the Astrogator MCS Run operation occurs, so that dependent computations are updated. Previously missed updates could have resulted in graphics that did not match computations, such as relative orbit lines, model orientation, and VGT graphics display. |
| PLAT-40540 | Atmospheric density plugins now correctly return atmospheric pressure and temperature values when the density model registers that it provides these values. |
Aviator
The STK Aviator capability provides an enhanced method for modeling aircraft that is more accurate and more flexible than the standard Great Arc propagator. In the STK v13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| AIR-10375 | The flight envelope for the SmoothAccel Basic Maneuver Strategy has been extended to support flight at negative load factors. |
| AIR-10378 | You can now specify the minimum AOA for Aerodynamic models for which that parameter makes sense. |
Chains
The STK Chains capability determines the times when one object can see another not by direct line of sight but by means of a third object. In the STK v13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| PLAT-40610 | The Chains_R Intervals Connect command now correctly returns Chains access intervals after the point in time when the definition of an object that affects a Chain access is updated. |
| PLAT-40638 | A Chain that ends in a Constellation object or Subset no longer reports that the light time delay is too long for the results to remain valid when the light time delay value of the last leg exceeds 2.0 seconds. The light time delay check is now applied to the leg previous to the last le, or not at all, when the Chain contains only single hops. |
| PLAT-40643 | Chains did not allow connections to be added to strands once an end object was encountered, even if valid connections existed from the end object to other objects. This made it impossible to compute all valid paths through a constellation when a constellation was used as the start and end object and multihop capability was allowed. This has been corrected. |
| PLAT-40675 | Using a Scalar Calculation File (.awb) as the Chain Optimal Strand metric sometimes resulted in incorrect optimal strands being computed. Chains was always using the first calculation scalar component listed in the file, but exporting a calculation scalar did not always guarantee that the first component in the exported file was the component selected to export. Exporting an Analysis Workbench component now always places these exported components first when exported, and Chains has been updated to look for the imported calculation scalar that has no dependents in the *.awb file. This will result in the proper optimal strands even if there are unordered *.awb files. |
Communications & Radar
The STK Communications & Radar capability simulates the performance of communications systems in the context of a mission. In the STK v13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| COMMRAD-3816 | The STK application now accepts a greater range of angles when importing FFD files from HFSS. |
| COMMRAD-3831 | The STK application now properly loads a scenario that was saved with the VOACAP atmospheric absorption model enabled. Previously, loading these scenarios would crash the application. |
| COMMRAD-3863 | The ability to select the Urban Propagation Wireless InSite 64 model on any object other than the Scenario object has been removed. |
| COMMRAD-3884 | The STK 13 version of the Scalable Networks Modeling Interface has been updated to be compatible with EXata version 8.3.1. |
| COMMRAD-3908 | The HFSS EEP Array antenna GUI now shows the target Selection Method and related fields. |
| COMMRAD-3944 | You can now configure the HFSS EEP Array antenna within the Component Browser. |
| COMMRAD-3963 | The Dolph-Chebyshev beamformer gain was showing unusual changes when you set the sidelobe level greater than -12 dB. Gain levels for these cases are now at expected levels. |
| COMMRAD-4001 | The ITU-R P.676-13 atmospheric absorption model will check the link frequency against limits of the model. If the link frequency is outside the limits, the model will not compute and will instead return a loss of 3000 db. STK software will send a message about this to the Message Viewer. You should check the Message Viewer frequently for any unusual conditions. |
Coverage
The STK Coverage capability takes coverage analysis capabilities to the next level by extending visibility analysis to discretized distributed areas, as seen from a collection of assets. In the STK v13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| GFX-7693 | Figure of Merit Satisfaction graphics were always appearing on the surface of the central body if the grayed out (not used) Contour Type option was set to smooth contours, even if you set the option to display graphics at altitude. Now, the graphics appear at the altitude you set. |
| PLAT-40603 | Access Constraint Figure of Merit parameters that use CrdnCalScalar or CrdnVectorMag constraints now correctly report their units for the dimension of the underlying Analysis Workbench (AWB) component. Previously, these Figure of Merit parameters always considered their dimension to be unitless, no matter the setting of the AWB dimension, so that the value being reported was always expressed in the internal units of the dimension of the AWB component. |
| UI-997 | The Coverage Tool Color Ramp generator no longer accepts a ramp size of 1. |
EOIR
The STK EOIR capability models the detection, tracking, and imaging performance of electro-optical and infrared sensors. In the STK v13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| EOIR-1071 | Point-source targets in a sensor scene now return the correct Az/El. |
RF Channel Modeler
The Ansys RF Channel Modeler™ capability enables you to analyze network interactions for RF communications and radar within an STK scenario. In the STK v13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| COMMRAD-3887 | Improvements have been made in how the RF Channel Modeler plugin computes the SAR/ISAR imaging target's bistatic relative velocity. The change impacts only bistatic Radar SAR/ISAR analyses. |
| COMMRAD-3931 | In the RF Channel Modeler plugin, when computing a Radar SAR/ISAR analysis with the Range-Doppler imaging feature not enabled, the plugin now uses the correct waveform bandwidth in the computation of the channel response. |
| COMMRAD-3939 | The STK application interface with the RF Channel Modeler plugin was allowing invalid scenarios where a Radar ISAR analysis configuration would allow you to configure a radar target that also happened to be a host for radar transceivers that were included in the analysis. This led to cases where there was no range between the target and the transceiver, which is not a valid configuration. Validation logic has been added to prevent you from configuring this type of scenario. |
STK Engine on Linux
STK Engine on Linux enables engineers and scientists to rapidly build and deploy custom software applications that embed Ansys' premier geodynamic analysis and visualization engine. In the STK v13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| PLAT-40705 | Setting a property in the Python API enumerations that derives from IntFlag no longer causes a TypeError when using recent Python versions. |
| PLAT-40806 | A new AGI.STKX.Controls.Interop.dll variant has been introduced to target .NET 9 and later. This assembly enables you to use the STKX controls in a .NET 9 application by referencing the .NET 9 Windows forms assembly, which no longer relies on the BinaryFormatter type. The new assembly is located under bin/Primary Interop Assemblies/net9. You should use it for projects targeting .NET 9 and later. |
STK general
The STK general list contains corrected issues that affect the STK application as a whole. In the STK v13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| ANLY-207 | A new Connect command, CreateObstructionFile, has been created for a Sensor to report out obstruction directions corresponding to a sensor's body mask or Az-El mask file. This gives a simpler picture of the obstruction boundaries than the sensor body mask format. |
| ANLY-1205 | The Sensor Pattern Intersection data provider now returns the correct values for altitude when the projection type is set to Central Body. |
| ANLY-1244 | When using the NIMA/NGA Terrain Directory (DMED) terrain format, you now get accurate position altitude for all locations. Previously, the altitude was inaccurate for certain position locations. |
| DOC-1804 | Upon installing and licensing the STK application, a new Product Selection splash screen appears, prompting you to choose the licensed product that you want to launch. |
| GFX-7635 | When saving and reloading 3D Window Text Annotations defined by cartographic coordinates, the annotations now retain their proper positions in the scene. |
| GFX-7713 | When using NVidia RTX graphics cards, Proximity visualizations (Control Box, Bearing Box, etc.) now display properly. |
| GFX-7715 | In cases where range rings were enables in the 3D Graphics Properties but left disabled in the 2D Graphics settings, a crash sometimes occurred, but this no longer happens. |
| PLAT-513 | The STK application can now add star objects in addition to satellites via Deck Access. The AddSatellites option for the DeckAccess Connect Command has been deprecated and an AddObjects option has been added which supports both satellites and stars. |
| PLAT-529 | The AdvCAT tool can now work with covariance data that does not cover the entire ephemeris interval when the "Do not require ephemeris for entire analysis interval" option is selected. |
| PLAT-1653 |
The following plugin properties were write only and are now read-write: IAgAsEphemFileReaderPluginResultEphem::IsValid IAgAsEphemFileReaderPluginResultEphem::Message IAgAsEphemFileReaderPluginResultEphem::CentralBody IAgAsEphemFileReaderPluginResultEphem::CoordinateSystem IAgAsEphemFileReaderPluginResultData::IsValid IAgAsphemFileReaderPluginResultData::Message IAgCrdnVectorPluginResultReg::Dimension IAgCRPolarizationLinear::TiltAngle IAgCRPolarizationLinear::ReferenceAxis IAgCRPolarizationElliptical::TiltAngle IAgCRPolarizationElliptical::AxialRatio IAgCRPolarizationElliptical::ReferenceAxis IAgSTKXApplication::UseHook IAgStkCommRdrAbsorptionLossPropagateSignalParams::NoiseTemp IAgStkCommRdrAbsorptionLossPropagateSignalParams::AbsorpLoss IAgStkRadarClutterGeometryPluginRegInfo::ValidRadarSystems IAgStkRadarRcsComputeParams::PrimaryChannelRcs IAgStkRadarRcsComputeParams::PrimaryChannelRcsCross IAgStkRadarRcsComputeParams::OrthoChannelRcs IAgStkRadarRcsComputeParams::OrthoChannelRcsCross |
| PLAT-1697 | In the Python API, the IAgEntity and IAgRadarAntennaBeam interfaces were updated to match the casing of similar properties in other interfaces. In particular, "ID" was replaced by "Id" and "BeamWidth" was replaced with "Beamwidth." |
| PLAT-40490 | The STK application no longer crashes when a Connect command connection is closed prior to an answer being sent by the application. |
| PLAT-40493 | Vehicle attitude slewing now slews correctly when the end slew state is inertially fixed. |
| PLAT-40523 | You no longer need at least an STK Premium or STK Enterprise license to use the True of Date, True of Epoch, and True of Orbit Epoch coordinate systems used in the Orbit Wizard. |
| PLAT-40591 | Satellite Collection objects now support the Rename Connect command. |
| PLAT-40700 | The Star property "ProperMotionRadialVelocity" has been renamed to "Radial Velocity" and has been updated to the correct unit type of Rate, which was previously Distance. |
| PLAT-40788 | All data providers for Planet objects now correctly generate data when it is available. Specifically, the LLA State, LLR State, Apparent LLA State, and Apparent LLR State data providers now perform proper validation checks so that the data providers will report data as intended. |
| PLAT-40896 | Installing the STK application to a location other than the default location no longer causes the MATLAB Connectors to fail to be detected, even when the length of the STK install directory is less that the length of the MATLAB install directory. |
| SEET-258 | To ensure mathematical stability, a minimum of three thickness values for dose calculations is imposed when using the IRENE radiation model. Fewer thickness values will result in an error. |
| UI-7300 | When deleting an object group and its children, the children are now actually deleted from the scenario instead of just being removed from the Object Browser. |
| UI-7328 | For Japanese Windows OS, sizing is now correct for Data Update Utility, Aviator Performance Model Wizard, and Procedure Properties screen/control. |
Test and Evaluation Tool Kit
The STK Test and Evaluation Tool Kit (TETK)™ capability is a suite of tools designed to support the test and evaluation activities of a mission life cycle across multiple domains, including aircraft, satellites, missiles, maritime, ground vehicles, and ground facilities.
TETK capability version 13.0 requires STK application version 13.0.
In the STK v13.0 release, you can find the following improvements:
| Issue ID | Release Note |
|---|---|
| TETK-399 | A new Connect command titled TE_VideoOverlay enables you to create and delete video overlays. |
| TETK-400 | You can now specify a reader when using the TE_Vector Connect command by using the Reader keyword. This keyword accepts both the reader name and file name. |
| TETK-862 | Previously, the Pick Window used the term "out of range" when data from another track could not be displayed. This term had been changed to "no data" for clarity. |
| TETK-1850 | Previously, when importing a first ownship into the TETK capability, a time array was created with the ownship's times before the scenario was updated. This presented a rounding issue when there was a large gap between the scenario time and ownship time. This issue has been resolved. |
| TETK-2925 | You can now toggle track picking on and off using the TETK Track Picking toggle button. The TETK Track Picking toggle button appears if a TETK track or ATC workflow does not exist. When a track or ATC workflow exists, the TETK Track Picking is enabled by default. |
| TETK-7151 | Previously, some built-in graphs were created with titles that had spaces. These titles now use underscores instead to maintain consistency with graph naming conventions. |
| TETK-7162 | The "No Signal Definition" warning no longer appears when opening the track filter, as this warning was unnecessary. |
| TETK-7221 | Previously, creating a graph with a spec set would set the extents incorrectly. The extents should now show the graph appropriately framed. |
| TETK-7414 | The TETK capability was causing large scenarios to load slowly. This was caused by an inefficient check of object ephemeris and attitude files that would sometimes need their file paths updated to work optimally with the TETK capability. This issue is now resolved. |
| TETK-7441 | When adding new units, the option to show units in the UI is now enabled by default. |
| TETK-7478 | There is a new Specification Workflow that you can now use to import and export specifications and execute them from the workflow. |
| TETK-7486 | The Specification Workflow now has validation criteria that will appear on the SpecSet Results dialog off the graph's menu bar. |
| TETK-7527 | TETK-generated time arrays no longer piggyback onto STK objects when they are duplicated via copy and paste. Additionally, Vector dialog's display of valid mappings were enhanced to display mappings valid for the current Analysis Object and its various attached readers. |
| TETK-7524 | Graphs now have Ellipse Annotations, and Box and Ellipse annotations now have Specification. You can use the TE_Graph Connect command to specify Ellipse Annotations. Additionally, the TE_Graph Save command has a new keyword called SpecSetResults that saves the results to a file. |
| TETK-2260 | The TETK capability now has Track Covariance display Connect commands. |
| TETK-7487 | The Specification Workflow now implements the criteria for Min, Max and Min/Max and shows the result in the graph Statistics popup. |
| TETK-7551 | There is improved cleanup of TETK scalar, geometry, and time artifacts when STK objects are copied or pasted. |
| TETK-7600 | Specification Workflow Execute now places the selected specs into the FAT and enables you to instantiate graphs. It also enables you to specify a time interval for the graph to be created over. |
| TETK-7601 | Specification Workflow now checks units if the metric is found in the scenario. |
| TETK-7605 | TETK Connect commands were updated to function properly in STK application version 13. |
| TETK-7623 | Previously, older STK scenarios or scenarios moved by a SaveAs would sometimes delete their TE_AppFiles folder and break the scenario. This issue has been resolved. |
| TETK-7633 | The Polygon annotation no longer throws an access violation. |
| TETK-7634 | Box/Ellipse annotation statistics now work correctly even when units are not SI. |
| TETK-7568 |
Previously, TETK-generated ephemeris files with a time step below 0.1 seconds were loading slowly. These cases now automatically trigger the setting of the SmoothData flag to speed up the process. |
| TETK-7732 | TETK units currently require the ability to write to the scenario directory. If a scenario is loaded from a directory the user does not have write access to, TETK will be disabled to prevent errors. |
| TETK-7755 | Previously, the Metric Satisfaction Interval calculations could use the incorrect values for a bounds evaluation if the metric unit was not an SI unit. |