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.

STK version 13.1.0 features

Highlights

  • STK 13.0 added the data rate Optimal Strand metric to Chains allowing for the computation of optimal strands based on the maximum data rates of the individual objects in the Chain. This metric allowed the user to answer the question of which single strand has the highest (or lowest) data rate at any given time. Operationally many networks, in order to maximize throughput, will allow data to be distributed across multiple strands simultaneously. Given a network of transmitters and receivers, at any given time what is the throughput capacity of the system based on designated source and destination objects? What nodes within the network are most likely to be bottlenecks during data transmission? STK 13.1 adds the ability to perform such network analysis using the same underlying computations used in the data rate optimal strand analysis. Total network throughput as well as individual object usage can be visualized in the 2D and 3D windows as well as reported and graphed using STK’s Report Manager tool.
  • glTF and 3DTiles support has been extended to include support for the meshopt mesh compression extension. This capability has been extended to the Terrain2Tiles utility to output smaller 3DTilesets of terrain.
  • You now have the ability to use the ITU-R P.676-13 propagation model, which includes locally known atmospheric data (barometric pressure, temperature, and water vapor density) as a function of altitude.
  • The Astrogator Differential Corrector and other similar search profiles will now execute 10-15% faster.
  • STK supports the ability to visualize and analyze the circular restricted three body problem on orbit families in a Satellite Collection object using the new CR3BP type.
  • STK now supports point Shapefiles for Deck Access. This extends the existing Deck Access support for line and polygon Shapefiles.
  • A color selected has been added to the Access tool to allow for setting a custom color of access graphics independent of the color of the objects involved in the access.

Analysis

  • Two new angles in the Vector Geometry Tool, BetaAngle(Sun) and BetaAngle(Moon) are now automatically created for each Satellite. These compute the angle between the apparent direction of the central body indicated to the orbit plane of the satellite. Note that the values differ somewhat from the BetaAngle data provider, as that data provider computes the apparent position from the satellite's central body Center point, and not from the location of the satellite itself. The new angles compute the apparent directions from the satellite itself.
  • A new Vector type, SurfaceNormal, is available in Analysis Workbench. This vector computes the vector normal to a central body surface from a given point. The surface normal vector may be computed from local terrain if enabled.
  • The Cartesian elements in the Vector ParameterSet in Analysis Workbench have been updated to include velocity related metrics, including speed, magnitude rate, and transverse rate.
  • The Polar-Nodal element set has been added to the Orbit ParameterSet in Analysis Workbench. The polar-nodal elements report radius, radius rate, transverse rate, true longitude, the angular momentum magnitude, the component along the Z-axis of the unit vector along the angular momentum vector (whose value is equivalent to cos(inclination)), and the nodal vector (i.e., cross product of Z-axis with the unit angular momentum direction).
  • Ceres Imagery has been updated to much higher quality imagery published by the USGS Astrogeology Science Center.

API

  • You can now configure Connect authentication with the following new properties that were added to the IAgSTKXApplication object model interface: AllowExternalConnect, ConnectTlsCertFile, ConnectTlsKeyFile, ConnectTlsCaFile, ConnectAuthMode, ConnectUdsDir, ConnectUdsId. A new AgESTKXApplicationAuthMode enumeration has been introduced to support the ConnectAuthMode property.
  • The agipcexp function, a program which provides an Internet standard protocol for remote terminal connection service, now supports the following new authentication modes: Windows Name User Authentication (WNUA), Unix Domain Socket on Linux, Mutual TLS, and Insecure.
  • ConnectExample, a Perl module included in the code samples for connecting to the STK application through a socket, has been updated to default to the UDS socket on Linux.
  • The experimental.jupyterwidgets STK Python API module has a compatibility issue with ipywidgets >= v7.x. Either install an older version of ipywidgets or Disable Kernel Comms over subshells in the jupyterlab settings.
  • You can now add and modify system noise temperature access constraints via the new IAgAccessCnstrNoiseTemperature object model interface. This interface includes all of the properties from a min/max access constraint and also supports the selection of different components of the system noise temperature to match what is available in the user interface.
  • STK now has a shared IAgGroundLocation interface for place, facility, and target objects. This interface includes all of the properties common to those objects as well as GroundLocationGraphics and GroundLocationVO properties which utilize new IAgGroundLocationGraphics and IAgGroundLocationVO interfaces.
  • You can now use the IAgScenario object model interface to set/get properties related to the Terrain Server.

EOIR

  • The Real-time Electronic Light Table options for the EOIR Details panel are the following:
    • Color spaces have been reworked to redraw in real time.
    • Image scrolling/navigating is faster.
    • Zoom limits have been increased.

    • Contrast and Brightness settings have been replaced with an Upper and Lower Bound setting. Raising the Lower Bound setting will raise the minimum value for a pixel's radiance/irradiance to show, while lowering the Upper Bound setting will lower the maximum value of a pixel before pixel saturation occurs.

  • For image quality, you can now select grid-based, spatially-varying point spread functions within an EOIR scene generation. You can then provide a CSV file representing their various PSFs combined and specify the rows and columns to evenly split the provided file in two, extracting each individual PSF and associating it with a region of the simulated scene.

STK General

  • The Generate TLE tool will now output results in the TLE format for SSC numbers up to 339999. Numbers greater than 99999 are now formatted using the USAF alpha5 format which uses a letter prefix and 4-digit number.
  • The Deep Space Network tracking system has been expanded to include new antennas, DSS23 and DSS33. Currently these antennas only have approximate coordinates.
    New JPL quasar radio source catalogs have been added, the 107F provides updated information on X-Band quasars while the 108A provides updated information on Ka-Band quasars.
  • You can now override the ephemeris start time for SP3 files for satellites and satellite collections.
  • The 2D map marker annotation now use pixel size instead of scale to determine how large an annotation marker is drawn.

STK Plugin for ModelCenter

  • Macros are now working in the STK Plugin for ModelCenter.

TETK

  • TETK Data Displays now support FMU 3.0 files exported from Ansys SCADE Display 2026R1. This enables you to design and model graphical items for displaying numeric and text values of data. You can then directly map TETK Data Elements to SCADE graphical components. This allows you to manipulate those graphical components based on the data values, similar to an SVG.

Training and Tutorials

  • Due to the deprecation of Analyzer as a stand-alone capability, all tutorials that used the Analyzer capability have been updated to use the STK Plugin for ModelCenter.
  • There is a new Level 3 Aviator tutorial, "Using Six Degrees of Freedom in Aviator," which explains how to build and simulate an aircraft's maneuvers with a full six degrees of freedom.
  • The Level 3 Aviator tutorial, "Aviator," has been updated with a new focus and is now called "3D Mission Editing with Aviator."
  • A new Level 3 tutorial, "Using External TLE and GPS Almanac Files," has been introduced to show how to import and use two-line element sets, GPS almanacs, and satellite outage files from external sources in the STK application.
  • Tutorials using GPS satellites have been updated to use TLE sets for accesses and communications; only the tutorials focusing on navigation accuracy and dilution of precision now use GPS almanac files.

STK version 13.0.1 features

gRPC and Connect network connections and authentication modes

The STK application defaults to disconnected for both gRPC and Connect. For Connect, this means that both single-machine and computer-to-computer network connections now default to off. You must deliberately turn on network connections. Remember that for Connect, you can always send commands through COM and the Object Model regardless of any network connection settings.

When connecting to the STK application through network connections via gRPC and Connect, you can now specify one of the following authentication modes:

  • Windows Name User Authentication (Windows only) - This restricts socket/network connections to the STK application to an individual user.
  • Unix Domain Socket (Linux only) - This restricts socket/network connections to an individual Linux user.
  • Mutual TLS - This restricts socket/network connections to the STK application to ones where both client and server authenticate each other through digital certificates.
  • Insecure - This allows open access to socket/network connections to the STK application.

    This option leaves the application open to unauthorized access.

For gRPC, you can specify network connection and authentication mode options by using the Edit Preferences settings for GRPC in the UI or by sending a GRPC Connect command.

For Connect, you can specify network connection and authentication mode options by using the Edit Preferences settings for Connect in the UI, by executing the AgIPCExp command line function with appropriate arguments, through the Python API, and through ConnectConsole.

STK version 13.0 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.

STK version 13.0 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.