What's New

This topic lists the new features and improvements that are included in each Ansys Systems Tool Kit® (STK®) version 13 release. If you want to read about known issues, issues fixed with each STK application version 13 release, and important announcements, see Release Notes.

To learn how to use the STK application, see the STK Tutorials.

Highlights

  • For all STK application licensing types (Pro, Premium, and Enterprise), the package installs both the STK application and the Ansys Orbit Determination Tool Kit (ODTK®) application. You need to obtain a separate license to run the ODTK application. When you launch the STK 13.0 application, a new Product Selection splash screen appears, prompting you to choose the specific licensed product that you want to launch.
  • For an Ansys STK/Astrogator® capability satellite, you can now pass spacecraft state information back and forth between the STK application and the ODTK application with the assurance of consistency in force modeling and propagation.
  • You now have access to the Cesium ion terrain server, a robust, scalable, and secure platform for providing your analyses with improved 3D geospatial data.
  • To enhance your Chains analysis for network modeling, you now can select a data rate metric for Optimal Strand.
  • The Access Constraints user interface now provides support for adding, modifying, and deleting constraints with multiple objects of the same class selected (i.e., multiselect).
  • You now have access to this improved Python API for the STK application, including enhanced documentation. Use PySTK to connect your applications to STK modeling.
  • The STK application now has an early assessment tool, STK Shield Plus, for identifying potential electromagnetic issues in your scenario. There are six automated workflows available: Shielding Effectiveness, Lighting Probability, Overbraid/Transfer Impedance, Rad-Hard (ionizing dose depth curves, requiring SEET), Surface Charging, and Ray Tracing.

Additional Enhancements

Integration with the ODTK application

Here are the main enhancements that enable the connecting of the STK application and the ODTK application.

  • There is a new Flight Dynamics Records folder in the Component Browser, making it easy to share with the ODTK application an initial state at a given time and the exact propagator functionality used to generate that state.

    • You can create a Flight Dynamics Record in the Component Browser using the New button in the Astrogator user interface, a new Connect command CreateFlightDynamicsRecord, or the STK Object Model interface with IAgVAFlightDynamicsRecordCreator.

    • You can import a Flight Dynamics Record into an Initial State segment using the Initial State tool or the InitialState Connect command. After importing a Flight Dynamics Record, most properties on the initial state segment become read only and in sync with the Flight Dynamics Record properties until the initial state is unlocked.

  • You can now propagate stochastic parameters in the Astrogator capability.

    • Specify initial conditions for the stochastic parameters on the Stochastic Parameters tab of the initial state segment.

    • Many Propagator Functions in the Component Browser now have additional options to support stochastic parameter propagation.

Cesium ion terrain server

You can specify endpoints on the Edit menu – Preferences – Data Services page. In addition, the STK application provides you with a collection of Cesium ion tiling tools to help you transform massive model or point clouds datasets into 3D tilesets for your specific scenarios.

We now offer licensing for three Cesium ion 3DTileset executables. You can find these executables on the Resources and Utilities installer disc. For help regarding these new tools, please refer to the Cesium ion help on the Cesium website.

  • AgIonModelTiler accepts the same command line arguments required to use the model-tiler.exe.

  • AgIonPointCloudTiler accepts the same command line arguments required to use point-cloud-tiler.exe.

  • AgIonRealityTiler accepts the same command line arguments required to use reality-tiler.exe.

Users of Cesium ion need to use the assets:limited-list permission token and not the assets:list permission token.

EOIR

There is now a quick toggle for minimum render mode that gives you easy access to faster rendering at the expense of subpixel accuracy. It is useful for high-FPS animations that are meant to run in real time during a scenario.

Aviator

  • The new Dynamics and Control procedure and accompanying performance model enables you to enter trajectories based on a time series of velocity, course, and flight path. You can then use the Ansys SCADE® application, Simulink, or Python via GRPC to provide control inputs to drive Aviator. To learn more about this functionality, see the help page.
  • There is a new L3 Aviator tutorial for the Air Rendezvous Simulation Tool.
  • Aviator now has a RelativeToWaypoint site that (1) employs a Catalog waypoint to fly to a bearing/range offset from that catalog waypoint and also (2) sets that catalog waypoint to be a valid choice for basic maneuver guidance strategies. This particular combination means you can define sophisticated “template missions” that can be easily moved anywhere on Earth.

RF Channel Modeler

The Ansys RF Channel Modeler™ plugin now supports providing roughness for the custom materials in the scenario rfcm_materials.json file.

In the RF Channel Modeler plugin, you can now independently size the imaging grid in both the range and cross-range directions. You also have the option of specifying the number and spacing of grid lines independently in range and cross-range.

Communication and Radar

  • The STK application can now accept FFD antenna files produced by the Ansys HFSS application, versions 2025R1 and later.
  • Sample HFSS exported antennas are now included in the STK application install.
  • For the element configuration file of a Phased Array antenna, you can now enter values in units of meters in addition to units of wavelengths.
  • Blade RCS clutter now accounts for the wind direction and the turning of the plane of wind turbine Blade rotation. This is in addition to the Doppler clutter previously produced by the blade tip rotation toward the radar receiver antenna.
  • The STK application implementation of the ITU-R P676-13 atmospheric absorption model now supports section 2.2 of the specification, enabling you to apply modeling for water vapor attenuation.

Astrogator capability

  • To more closely align with common mission data, the Astrogator/HPOP default spacecraft initial state parameters changed as follows:
    • Epoch at 1 Jan 2026 1200
    • Altitude from 300 km to 500 km
    • Masses: dry mass from 500 kg to 50 kg, fuel from 500 kg to 50 kg, max fuel from 1500 kg to 150 kg
    • Tank volume consistent with max 150 kg
    • Drag, SRP, and radiation pressure areas from 20 m2 to 2 m2
  • There is a new default propagator, Earth High Fidelity v13, that replaces Earth HPOP Default v10, which is now located in the Previous Versions folder.
  • Galileo satellites now have updated/added attitude profiles. What used to be called "Galileo IOV" has been renamed to "Galileo Nominal" and two new profiles "Galileo IOV" and "Galileo FOC" have been added to incorporate the modifications to the nominal law during low beta angle situations during a noon or midnight sun.
  • The default method to compute the Sun position for solar radiation pressure models in HPOP and the Astrogator capability is now "Apparent."
  • The “Astrogator” folder in the scenario and install directories has been renamed to “Flight_Dynamics.”

Analysis

  • The Active Constraints data provider now contains additional data elements that were previously only in the All Constraints data provider, such as Dimension and Min andMax settings for MinMax constraints. For a full listing, see "Active Constraints" in the Data Provider section of the Help.
  • There is a new Connect command for sensors, CreateObstructionFile, to report obstruction directions corresponding to a sensor’s body mask or Az-El mask file.
  • Additional data elements have been added to Data Providers reporting AWB Vectors to report Magnitude Rate (the component of velocity along the vector), Transverse Rate (the component of velocity perpendicular to the vector), and Angular Rate (the magnitude of the angular velocity of the unit vector aligned with the vector).
  • Access constraint Figures of Merit no longer require constraints to be enabled in order to provide user settings to the access constraint for its value to be computed. You can now configure constraints such as ObjectExclusionAngle, CrdnAngle, CrdnCalcScalar, and others on the Grid point object's Constraint list. You can disable the constraints so they do not affect the Coverage computation while still having Coverage compute the FigureOfMerit value for them.
  • The direction of the ToStar Vector, defined in the Vector Geometry tool, has been corrected to include the J2000-to-ICRF frame conversion for Stars defined by a catalog that uses the J2000 frame natively (e.g., the Harvard catalog). Previously, this conversion was ignored. The difference in direction will be very small since these frames are very close to each other.
  • The ionspheric model has been updated with coefficients for the IGRF 2025 magnetic field. In addition, the definitive 2020 model, DGRF2020, was added and is used when computing the magnetic field between 2015 and 2025.
  • The AWB Filtered Time Array component now enables you to specify the filtered intervals by just one Time Interval instead of an Interval List. Previously, if you wanted to use just one Interval to filter the times, you had to create a new Time Interval List containing your Time Interval of interest to use as the input. Now you can just use the Time Interval directly.
  • Better default sampling settings have been created for the Time of Extremum Time Instant, the Times of Extrema Time Array, and the Satisfaction component for Interval List and Collection of Interval Lists. These components compute faster by default while still providing accuracy. You may still override the default settings to ensure accuracy with performance when you know the frequency content of the underlying calculation scalar.
  • DataRate is now exposed in Analysis Workbench via the CommLinkInformation parameter, and you can set it for accesses involving a transmitter.
  • The Analysis Workbench Filtered Time Array component now enables you to specify the filtered intervals by just one time interval instead of using a list.
  • Analysis Workbench now provides the following additional data for vectors: magnitude rate, transverse rate, and angular rate.

Behavior Execution Engine (BEE)

  • BEE now supports SysML v2 models you create using the Ansys System Architecture Modeler (SAM)™ capability.

STK General

  • Access computations are computed more accurately when using a sensor body mask constraint where the body mask file contains boundary points that are widely separated. By default, additional subsamples will be added to the points in the file following a boundary that lies in plane between samples. You can control this default behavior further by specifying the boundary interpolation method and maximum angle between samples in the body mask file.
  • The Object Model interface now exposes an Enabled property that enables or disables the use of a constraint in Access computations.
  • Additional precision has been provided for the rate values listed in the rotational coefficients files for Mars, Deimos, Phobos, and Neptune. These files are used to generate attitude for these central bodies using a standard IAU algorithm.
  • Subsets of Satellite Collections that assign a reference template object for a subset now correctly update their entries when the collection entries are updated.
  • The Earth magnetic model data was updated to IGRF-14 and WMM 2025.
  • The STK Application can now export ephemeris files in CCSDS OEM version 3.0 format. The STK Application also supports versions 1.0 and 2.0. For more information, see the help.
  • The body-fixed attitudes for several central bodies have been updated to use the attitude parameters provided by the "Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2015", published in the journal of Celestial Mechanics vol. 22, 2018. The updated central bodies are Ariel, Callisto, Europa, Ganymede, Io, Jupiter, Mimas, Rhea, Tethys, Titania, and Vesta.
  • You can now export the Initial State files in CCSDS OPM format via the Export Initial State tool in addition to previous support through the InitialState Connect command. CCSDS OPM versions 1.0, 2.0, 3.0 are all supported in both the UI tool and Connect command.
  • The IAU algorithm used to compute the attitude for central bodies using parameters from a rotational coefficients file now uses the TDB time scale rather than the TDT time scale when computing seconds since the reference epoch of J2000. This agrees with the description of the algorithm in "Report of the IAU Working Group on Cartographic and Rotational Elements: 2015", Celestial Mechanics, vol 22, 2018. Some earlier IAU reports indicated that the accuracy of the model was such that use of TDB or TDT provided the same information content that either time scale could be used. Later reports, however, show a clear preference for using a relativistic time scale appropriate for the solar system barycenter, not TDT.
  • The STK application can now add star objects via deck access in addition to satellites. The AddSatellites option for the DeckAccess Connect command has been deprecated. An AddObjects option has been added, which supports both satellites and stars.
  • 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.
  • There is a new L3 SEET tutorial call “Computing Radiation Dosages Using SEET and the IRENE Model.”
  • Parallel Computing has an updated installer graphical user interface.
  • STK online server names have changed for version 13.
  • The default host for gRPC has been changed from "0.0.0.0" to "localhost."
  • You can now disable all online operations for all users on a machine via a registry setting, so an administrator can now override any user settings and not allow the STK application to retrieve data from the internet. More information is available here.
  • 3D models using glTF (*.glb) format have a new lighting environment and may appear shinier than before.
  • Added the ability to change the start/stop time of the scenario in an Analyzer trade study.

TETK

  • You can now toggle track picking on and off using the TETK Track Picking toggle button. This 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.

  • You can now import and export specifications and execute them from the new Specification Workflow. The workflow has validation criteria that appears on the SpecSet Results dialog off the graph's menu bar. Additionally, the workflow implements the criteria for Min, Max, and Min/Max and displays the result in the graph Statistics dialog.

  • Specification Workflow Execute places the selected specs into the Flight Analysis Tool (FAT) and enables you to instantiate graphs. It also enables you to specify a time interval for the graph to be created over.

  • 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.

  • A new Connect command titled TE_VideoOverlay enables you to create and delete video overlays.

 

Click here for the STK 12 Release Notes.