What's New

STK 12.7 feature highlights

Satellite Collection

• You can now use Satellite Collection objects as endpoints for object lines in the 2D and 3D Graphics windows.
• You can now create a Satellite Collection object from a set of SP3 files (often used to model satellite navigational systems).
• Satellite Collection subset graphics options can now be saved to the default Satellite Collection file, allowing for subsets to be shown automatically when new Satellite Collection objects are created.
• You can now create your own Satellite Collection subset from the Satellite Collection Definition properties page using a new Add button and the accompanying dialog box. For instance, you may create subsets based on filters derived from metadata contained in the database used to define the Satellite Collection.

Terrain Analysis

• When the terrain server is enabled for computing AzEl masks and/or line-of-sight terrain mask computations, STK now uses the Geospatial Content Server (GCS) for computations involving terrain. Previously, GCS only provided terrain tiles for visualization purposes.
• A new setting has been added for Facilities, Places, and Targets, to control the computation of an AzEl mask using terrain data. You can now specify a maximum (ground) range to consider when sampling the terrain. This allows you to choose the appropriate distance for the situation being modeled. Additionally, the default value is now 50 km, whereas in previous versions, STK used 167.8 km.  This new default distance makes the computation of the mask faster, while generally remaining accurate enough for most use cases.

General

• The STK Python API has been improved to provide better IDE support (Intellisense) for enumeration values and the packages now make use of __init__.py files. The code previously in agi/stk12/stkobjects/stkobjects.py, agi/stk12/stkobjects/aviator/aviator.py, and agi/stk12/stkengine/stkengine.py has been moved to the corresponding __init__.py in their respective folders.
• The Export Ephemeris/Attitude Tool, available for all vehicles, now supports exporting ephemeris in more reference frames. The TrueOfDate frame is now available as a frame choice for all central bodies. The TEMEOfDate frame is now available when the central body is Earth, and the the MeanEarth frame is now available when the central body is the Moon. The CCSDS and CCSDSv2 formats also support TEMEOfDate as a frame choice when the central body is Earth.
• STK now supports the use of the AFSPC SP DLL, version 8.x, as a propagator. Note: AGI provides only the interface to the propagator. AGI cannot provide the actual AFSPC SP DLL, which is only available to authorized users from www.space-track.org. Contact customer support for additional installation guidance if needed.
• You can now specify mask reference axes for AzEl and Body masks used by sensors. The azimuth and elevation values in the file are no longer restricted to be measured relative to the parent's body frame, though the parent body axes remains the default when you do not specify the axes in the file. Masks may now be defined relative to any reference frame associated with the parent object. 
• You can now choose the UpVector option for sensor pointing. This option constrains the sensor's X axis to the direction of the specified vector, offset by a clock angle.
• STK now supports all ITRF frame versions during import and export of ephemeris that model the Earth's Fixed frame differently. The differences in position computed using different ITRF frames are very often less than 10cm, but older frames (e.g., ITRF1993) may differ by up to one (1) meter from newer ones (i.e., ITRF2020) and newer ones may differ on the order of millimeters from each other. 
• The ITRF axes and system have been added to Analysis Workbench for the Earth central body. The axes and system are fully equivalent to the Earth's Fixed axes/system.
• STK save and load dialogs now support modern Windows capabilities, as well as, a modern look and feel.
• Pasting an SDF URL into the file selection dialog now properly reflects the file selection in the dialog tree.
• The Component Browser now provides the means to designate a component as a User Collection component, which enables you to apply it to other scenarios.

Communications & Radar

• Radar STC now supports a user provided COM Plugin option. An example of a C# plugin is included with STK along with the Radar Clutter and RCS plugin examples.
• Created a new five-part Communications series for STK's Communications capability. This series covers the essential skills required to simulate your communications systems in STK. The AGI Training team has made videos for each lesson to guide you through step-by-step. The AGI Training team also updated Track 5 of the Level 3 STK Grand Master Certification to reflect the new Communications lessons. The five lessons are as follows and you can find them in the Feature-specific tutorials in the STK Help:
  • Communications Part 1: Introduction to STK Communications
  • Communications Part 2: Introduction to RF Environment, System Noise Temperature, and Terrain
  • Communications Part 3: Introduction to Analyzing Digital and Analog Transponders
  • Communications Part 4: Introduction to the Terrain Integrated Rough Earth Model (TIREM)
  • Communications Part 5: Introduction to Modeling Propagation Loss in an Urban Environment

EOIR

• When you right-click the sensor scene in EOIR, you can now select the Show Zoom Slider option to have the sensor scene display a slider at the top of the scene. Move the slider to the left to zoom out and to the right to zoom in.
• The temperature value for the plume option in the EOIR stage properties of missile objects now supports values between 0 Kelvin and 50,000 Kelvin.
• The EOIR Help now has more robust descriptions for Number of Pixels (Spatial), Auto Rebalance Parameters (Optical), and custom image quality functions (Optical) as well as diagrams for Target Signature File clarification.

Aviator

• Added the Formation Flyer Procedure: This procedure maintains formation with a cooperative flight leader and calculates significantly faster than alternative formation procedures that are based on Basic Maneuver methods. This new procedure reduces analysis time for customers carrying out long-range formation flight, providing up to a 90% reduction in calculation time over Rendezvous procedure.
• Added an option for No Thrust When No Fuel to the Advanced Fixed Wing performance Powerplants. Added a choice for the SimpleMissile propulsion model to the UserAircraft Acceleration model.
• Aviator 3D edit now looks at properties common to previous and new procedures, in order to carry forward properties. This should reduce the mouse clicks involved in setting up new missions through 3D edit. Common properties include: Enroute Airspeed, Hold/Arc/Second Airspeed, Turn Radius Expansion, Max Speed Turns, and Enroute Heading The direction that the aircraft is pointing./Course Options
• Added a checkbox to filter out invalid rows when importing external aero files in the Aerodynamics tab. Invalid .aero file rows are rows where any of these values: ClAlpha, K or Cd0 are less than zero. 
• The feature that automates the tasks of running the Design Points Generator tool has been updated. It also now provides a warning to users when exporting flight conditions that are not optimal for usage in the tool.
• Aviator Performance Models added as possible analysis parameters. Not all the Aviator performance parameters are currently implemented.

Graphics

• Our default base globe imagery has been upgraded from the PlanetEarth 20km dataset to 1km resolution. The default imagery filename remains unchanged, and will now use this higher resolution imagery; our previous 20km resolution imagery is available under the new name Earth_PE_b_20km.jp2.
• STK can now ingest 3D tilesets that use the 3DTiles_content_gltf extension. This change enables you to more readily integrate glTF models into 3D tile capabilities within STK. As a result of this change, you can assign glTF models to any reference system and have the models participate in 3DTiles Mask access constraint.
• Using the Connect command "3DTiles * Analysis", you can now specify the "PATH" option to reference an STK Object (Facility, GroundVehicle, Satellite, etc.)'s model geometry for the 3DTiles Mask access constraint. With this change, STK can use the object's glTF model, including scaling and custom offsets, for visibility testing in Access calculations.
• Lighting visualization in STK has been improved to provide pixel perfect lighting to terrain for spot and positional custom light sources. Spot lights now exhibit softened shadowing at light boundaries.

Astrogator

• You can now use the Passive Safety tool for analyzing collision risk in RPO missions. This tool checks to assure that any failure during the execution of an RPO maneuvers will not result in a conjunction of the target and chase satellites.
• A tool to configure STK for three-body trajectory modeling using the circular restricted three-body problem (CR3BP) has been added to the Astrogator/Design Tools library in the Component Browser. This tool guides you through the creation of an idealized secondary body consistent with the mathematical model for the CR3BP as well as appropriate Analysis Workbench coordinate systems and Astrogator calculation objects. Upon creation of these fundamental components, you may now easily leverage the CR3BP propagator function without significant, previously required manual configuration. 
• For the Lambert Solver in Astrogator, you can now replace existing sequences with new ones having the same names.
• You can now use an acceleration history file to define an Astrogator finite maneuver.
• For any Astrogator finite maneuver(s), you can now generate an Astrogator acceleration history (accelhist) file directly from the STK Report & Graph manager without the need for an external post-processing script.
• The widths of columns in the differential corrector status grids have been adjusted to better display numerical values.

Analyzer

• STK Analyzer now supports configuring the RAAN Spacing or RAAN Spread for a Satellite Collection Walker Custom Shell.

Documentation

• The Help has been updated to better define how to create UI plugins.
• These lessons are completely new for 12.8:
  • Coverage over the Satellite Graveyard
• These lessons have been completely re-written:
  • Satellite Constellation Design with Analyzer
  • Basic Satellite Design in STK with SatPro
  • Formation Flyer and Aircraft Refueling with Aviator
• These lessons were updated with the new Chains updates:
  • Communications Part 3: Introduction to Analyzing Digital and Analog Transponders
  • Evaluate Laser Communication Links
  • Modeling Near-real-time Relays in STK
  • Part 6: Introduction to the Pro Capabilities
  • Satellite Collection Object: How to Use External Files

STK 12.6 Feature highlights

Analyzer

• STK's Analyzer capability now supports performing trade studies with satellite Lifetime parameters.

Astrogator

• Astrogator, HPOP, and Analysis Workbench can now use the DTM 2020 atmospheric density model .
• The Astrogator Radiation Pressure Propagator Function now allows for the definition of the Radiation Pressure Coefficient (Ck) and Radiation Pressure Area directly on the function itself. You can choose to use these values instead of the values defined on the MCS segments.
• Python support is now available for the Astrogator Scripting Tool. This multiplatform capability uses the STK Python API and enables the Astrogator Scripting Tool on Linux for the first time.

Aviator

• The first iteration of a repository for plugin examples for the Flight Framework is now available. This first iteration includes Aerodynamic and Powerplant strategies, so you can plug in your own computational methods and have them appear as if they are built in. The example Aerodynamic and Propulsion strategies model an X-34 hypersonic vehicle, making use of what is called a four-point aerodynamic math model using .NET. The propulsion model is coded using C++ in a form that is conducive to plugging in a Functional Mockup Unit (FMU) as a propulsion force model.  
• There is now registration-free .NET plugin capability to 30 different Flight plugin points. This supports the forthcoming Flight Sandbox capability, supporting Ansys developers around the world to integrate their tools with STK and Flight.
• There is a new Aircraft Plugin for STK Aviator to generate design points suitable for use with Fluent Aero. The design points produce an envelope that encompasses the selected mission, making it easy to compute and use a high-fidelity AERO file for a family of trajectories around the selected mission.
• External ephemeris files can now create Aviator objects to determine appropriate attitude, aerodynamics, propulsion, and thermal models for external ephemeris trajectories. This can be used to determine the ability of an aircraft to follow desired trajectories or estimate aircraft performance characteristics given an observed trajectory.
• Hypersonic modeling is improved with a new glide strategy that interpolates commanded airspeed between initial conditions and specified airspeed and altitude. Available hypersonic vehicle trajectories now include changing airspeed as a function of altitude.

Communications/Radar

• For Access, a Comm receiver or a monostatic radar or a bistatic radar receiver can now check that a jammer or interferer transmitter (or a radar transmitter) is sharing the parent object with the receiver.  Previously, Access would not enable and compute such a pair. 
• Significant changes have been made to the configuration of radar clutter modeling in STK. The Clutter Map, which used to be configured on the radar target object, is now configured in the radar object on the clutter tab of the radar properties. The terms "Clutter Map" and "Clutter Geometry" are now called "Scattering Point Model" and "Scattering Point Provider", respectively. You will need to update scenarios authored by previous versions of STK to produce the same results for these scenarios using STK 12.6.

EOIR

• The EOIR temperature drop-down now allows selection of the Aviator Thermal model. This greatly improves the workflow for predicting thermal profiles of hypersonic trajectories.
• The Help section for STK's EOIR capability has a more user-friendly structure and includes a topic for EOIR installation.

GCS Terrain

• The GCS analytical terrain API is now integrated into STK. 

Graphics

• Changes to the way STK loads fonts now significantly improves the scenario startup performance.

STK 12.6 feature details

General

• You can now filter a Satellite Collection database search to only return satellites included in a user-defined TLE source file.
• STK 12.6 improves the functionality and documentation outlining how to use a sensor pointing file (*.sp) when you specify an Analysis Workbench frame, a central body frame, or no frame, and when the sensor's parent is a vehicle or a facility/place/target.
• STK now includes new, Python-specific methods for IAgDrDataSetCollection to ease numpy/pandas integration with data providers.
• STK now includes the following Windows containerziation code samples: stk-engine-baseline, stk-engine-connect, custom-environment, stk-engine-python, stk-engine-webservice, and stk-parallel-computing-server. This is in addition to the previously included Linux samples.
• You can now use the PersonalAccessToken Connect command to request tokens that will authorize STK to access your data on both the SDF and GCS.
• STK 12.6 improves and expands the cubesat model offering included with STK.
• You can now set a preference to have the Message Viewer open automatically when STK generates an error message. You can configure this preference by message severity level.
• A 3D Graphics window now includes an optional confirmation warning when it is closing.
• The option to have STK show 'Delete confirmation' was moved from the General preferences page to the Object Browser preferences page.
• A new grouping capability enables you to better organize scenario objects within the Object Browser.
• Autoclouds methods were removed from the Clouds ObjectModel API. Periodic updates of cloud imagery should instead be managed externally.
• In order to provide a more modern HTML5/JavaScript support and increased security, the Internet Explorer web control has been replaced by the Microsoft Edge WebView2 control when executing any of the following: License Viewer, Contact Technical Support or User resources from the Help menu, HTML balloons in a KML file, and STK UI Plugins to open an HTML Browser in STK. You can still use the HTML Viewer when loading scenarios containing open HTML Viewer windows. The HTML Viewer will be removed in a future release.
• IAgUiPluginHtmlWindowSite.NewWindow() now opens the Web Browser rather than the soon-to-be-deprecated HTML Viewer.
• All dynamic data (EOP, Satellite databases, GPS Almanac data, Space Weather, etc) have been updated. 
• An Object Model API has been added for Astrogator's Golden Section and Grid Search profiles.
• STK now supports the following native Python plugin points: EphemFileReaderPlugin and SearchPlugin.

Parallel Computing

• The Start Panel now includes a shortcut to start Ansys Licensing Settings for Parallel Computing, to enable you to quickly enter the host and port number of the license server.
• OSPlatform was added to CommonResources and OSPlatform enumeration was added. You can use these with TaskPreconditions to restrict tasks to run on specific OS platforms.

SEET

• Scaled Flux Intensity is now available from the SEET SAA Flux Intensity data provider.

Scheduler

• Scheduler now requires  ASP.NET Core Runtime 6.0.10 (x64) and  Microsoft .NET 6.0 Desktop Runtime 6.0.10(x64).   

Analyzer

• Analyzer now enables you to vary the Radar Cross Section (RCS) for all STK objects that support RCS.
• You can now choose to use STK Engine or a GUI subprocess for Model Center processing.
• Analyzer utilizes the STK units selected within the STK object constraint units.
• Analyzer now displays the same settings as selected in the Satellite Properties.
• Analyzer Probabilistic and Monte Carlo studies now have algorithms and wizards to help you determine the appropriate number of samples to run for an accurate result.
• Analyzer now supports running Close Approach studies.
• Analyzer now supports Astrogator script parameters for Trade Studies. 
• Analyzer will now display the dimensions/coordinates/units/configuration that are being utilized in STK for an object.
• The Analyzer STK Object tree will now display items with zero access.

Astrogator

• STK now includes Astrogator calculation objects for Mean Equinoctial h, Mean Equinoctial k, Mean Equinoctial p, Mean Equinoctial q, and Mean Mean Longitude.
• You can now use b-plane coordinates for an Astrogator initial state.
• A new report style, Accel File Python, has been added. This report uses a Python script in post-processing to generate *.accelhist files for ODTK. The associated script provides an alternative to the existing Perl script report, including various improvements over the legacy option. A working Python environment is required.

Aviator

• The BasicFighter 3D model has been updated to use an F-16, the most prevalent fighter in use in the world today.
• Aviator procedure intervals are now included within the MissionProcedureIntervals list in Analysis Workbench. Moreover, if a procedure contains subintervals, those will be published in the embedded interval list component, WayPointIntervals.
• Aviator now provides named Intervals as Analysis Workbench components, one for each flight procedure, as embedded components within the MissionProcedureIntervals IntervalList component. Similarly, each phase has a corresponding named interval in the MissionPhaseInterval IntervalList.
• The Advanced Fixed-Wing Subsonic and Supersonic Aerodynamic models now include Cl0 and ClAlpha Factor parameters. These parameters enable you to better model cambered wings and also support the calibration of aerodynamics to any data you may have.
• A new check box titled "Continue After Roll Complete"  is available for the Basic Maneuver Aileron Roll strategy. Selecting this box facilitates rolling to arbitrary angles and then holding those roll angles for a user-specified duration. This is useful for modeling knife-edge flight paths used in TETK.
• The Aviator Object Model API now includes refueling and dump properties.
• Aviator now includes the FastTimeOptions procedure, which improves performance over the previous ProcedureTimeOptions.
• Durations and downrange profile data are now available on both the graphical profile window as well as in the Profile Data dialog box.

Communications and Radar

• A new scattering point model has been added to model how radar energy is reflected by a wind turbine.
• A new points file scattering point provider model has been added for modeling radar clutter scattering points based on a text file. You can add the lat/lon/alt locations of the scattering points to the files, along with optional scattering point models. The scattering points will then be used in the computation of the total clutter received at the radar receiver.
• A smooth oblate earth model has been added as a new scattering point provider. This computes the scattering points based on iso-Doppler and isorange contours projected onto the smooth oblate earth.
• ITU-R P.618 rain model has been updated to the latest release: P.618-13.
• The Scalable Networks Modeling Interface's 'Scenario Explorer' workflow now enables you to add wired interfaces to any object in the Hierarchy, not just Facility, Place, and Target objects. This facilitates the inclusion of wired network subnets that might reside on a nonstationary object, for example, a wired subnet that resides on a mobile vehicle.

EOIR

• 'Sensor Define' and 'Sensor Modify' Connect commands now support EOIR sensors.
• You can now turn celestial body property maps on and off. This enables a number of useful effects for modeling and simulating dynamic backgrounds.

STK Engine on Linux

• AFSPC V7 SP is now available on Linux.

Documentation

• The Help has been updated to define the DE and SPICE files used in STK.
• A new lesson has been added on radar clutter modeling.

STK 12.5 Feature highlights

Large constellations

You can now include the Satellite Collection object within chained calculations to better analyze and understand complete routing options for connecting ground based assets. You can use STK's Chain object to create an order-of-operations workflow across multiple assets so that you can analyze end-to-end links across collections of dynamic objects. Use of a routing file provides a new mechanism for defining an almost endless number of allowable pathways between a constellations constituent objects.

Containerized Engine applications

STK 12.5 includes new documentation and code samples that explain and demonstrate headless execution of STK Engine on Linux applications within containers. This provides organizations with additional options for efficiently deploying STK applications in cloud based environments as well as maximizing the utility of existing hardware resources.

RF interference at the Receiver object

Now you can analyze the effects of a crowded RF environment on an individual receiver, making it quicker and easier to characterize interference and develop mitigation strategies. STK's Comm System object is used to analyze groups of objects. With this pairing, you can now choose which workflow is best suited to your specific analysis task.

VOACAP

STK 12.5 introduces an enhancement that enables you to account for solar activity in atmospheric absorption by specifying a solar flux index. In addition, when using VOACAP model for over the horizon HF propagation, this release of STK enables you to report on multiple dopplers from skywave propagation paths that include a ground bounce. Analyzing multiple dopplers improves your understanding of the characteristics of objects in motion.

EOIR

STK 12.5 improved the modeling capability for EOIR sensor simulations by providing enhanced central body property maps. These property maps account for overlapping texture maps and enable you to model temperature, emissivity, and reflectance at higher fidelity.

With STK 12.5, you can now model ground vehicles and ships in EOIR and generate sensor-to-target metrics that incorporate these objects.

Astrogator Venus GRAM

For STK 12.5, we added a higher fidelity atmospheric model for Venus. NASA's VenusGRAM model provides high fidelity engineering estimates for temperature, density, pressure, and winds for the Venus atomosphere. You can include the effects of this atmosphere model on your spacecraft's trajectory when its missions may be influenced by the planet.

Aviator

STK 12.5 enhances the interoperability of STK Aviator capability with Ansys Fluent. You can now use aerodynamic parameters that have been imported from Fluent in aircraft models that use Aviator's Advanced Fixed Wing tool and its Missile catalog.

STK 12.5 feature details

General

• STK can now run on Windows 11 operating systems.
• The STK documentation now includes clear instructions for running STK in a container , and the STK install includes some starter samples.
• Native Python plugin points have been added to STK for HPOP Density Model, HPOP Drag Model, HPOP EOM Func, HPOP Force Model, HPOP Light Reflection, VGT Axes, VGT Point, VGT Vector, Astrogator Attitude Control, Astrogator Engine Model, Radar Clutter Geometry, Radar Clutter Map, and Radar RCS plugins.
• The Python code snippets presented in the Help have been updated to use the new STK Python API.
• A modern Edge browser with Chromium controls has been added to browse HTML pages, enabling advanced HTML and JavaScript usage and modern libraries.
• STK's MATLAB connectors are now compatible with the latest version of MATLAB 2022a.
• The TimeFormat keyword in an STK External Ephemeris file (i.e., *.e file) is now read and understood in the Covariance section of the file (since STK 11.6).
• There is an additional preference in Edit menu > Preferences > General that you can select to show the full path for recent files.

Chains

• Satellite Collection subsets are now available for use in routing definitions in Chains.
• For a Constellation Object or Satellite Collection Subsets, you can use a Routing file to specify the ways the objects link to one another and to adjacent objects inside a chain.

General Astro

• You may now specify availability restrictions in the orbit definition files and supplemental metadata files used by the Satellite Collection object. You can use these to limit the available times of entries (e.g., to prevent use of an object after a specified decay date).
• New metadata has been added to SatelliteCollections. When the orbit definition file type is OrbitElements, the six orbital elements that define the orbit for each satellite entry are added as metadata. When the type is Ephemeris, the filename is added.
• The default ocean tide model for the Earth has been updated to the FES2014bv1 model.
• STK has updated the ephemerides of its central bodies to use the latest JPL SPICE files. The primary bodies/barycenters are modeled using the latest JPL-developed solar system ephemerides (DE440) and the moons of Jupiter, Saturn, Neptune, and Pluto have been updated with the latest available files.
• STK now provides ephemeris for 19 significant asteroids in its STKData/Spice/asteroids.bsp file that ships with the interplanetary options.
• The Ceres central body ephemeris has been modified to now use a JPL SPICE file for its ephemeris. This ephemeris is now shipped in STKData/Spice/asteroids.bsp.
• The All Satellites Walker report style has been updated to include the orbital elements for each entry as additional metadata.
• The default ephemeris source for the Vesta central body has been updated from orbit elements to use JPL Horizons SPICE ephemeris. This provides a higher fidelity model than the orbit elements provide.

3D Graphics

• Artistic lens flare and vignette options have been added to the 3D window.

Access

• A new Min/Max Access constraint has been added that you can use to model when an object comes close to the boundary of an Area Target. This uses the smallest surface distance between the Area Target boundary and the subpoint of the other object.
• Lead angle has been added to the Access ConstraintData data provider. Lead angle is the angle between true and apparent relative positions. It is evaluated at the time of the transmission or reception of the signal by an object, and is reported as a positive value for the object that is transmitting, and a negative value for the object that is receiving.

Analysis Workbench

• STK now supports reg-free .NET VGT plugins for vector, point, axes, and calcscalar components. To build, register, and deploy registry-free VGT engine plugins, see Building Engine PluginsBuilding Engine Plugins in the STK Programming Help.

Coverage

• You can now use Area Target objects as Single_Object Coverage assets.
• New options have been added to define the satisfaction interval associated with the Access Separation Figure of Merit.

Astrogator

• The 2005 version of the Venus Global Reference Atmosphere Model (GRAM), previously available in a beta form, is now available out of the box for use with Astrogator.
• Astrogator now directly supports a tabulated area vector SRP model, the SPAD model, previously available as an STK EOM plugin.
• The Astrogator calculation objects for thrust vector components have been updated to default to Earth ICRF for their reference frame (i.e., Earth Inertial) as opposed to their previous default of J2000.
• Astrogator now has an option to keep stopping conditions active on a finite maneuver seeded from impulsive by a Seed Finite profile (other than the "Duration" stopping condition). This enables additional workflows that require other stopping conditions to be active, such as using a Delta-V stopping condition in conjunction with a scripting profile following a seed finite profile. Particular consideration should be given to which stopping conditions on the finite maneuver may be triggered first while using this option.
• Astrogator calculation objects have been added for Mean, Median, and Standard Deviation of a value.
• Astrogator has two new target profiles: One Dimensional Grid Search and Golden Section Search. This includes accompanying documentation.
• There are new buttons on the Astrogator Target Sequence and Astrogator MCS settings to change the run mode of all profiles in a target sequence and in the MCS, respectively.
• There is now an option for the Astrogator MCS Delta V Squared and Sequence Delta V Squared calculation objects to be calculated as either the sum of squares or square of sum of Delta Vs.
• You can now export the State Transition Matrix from an Astrogator satellite to the .e file.
• There is a new dialog box on the Astrogator Initial State segment that enables setting the entire initial state in one place.
• There are two new Astrogator RPO sequences: Lambert Rendezvous and Lambert Match Orbit.
• You now have the ability to switch between whether the calculation object used in an Astrogator UserSelect stopping condition is linked or unlinked to the version in the component browser.
• You can now select whether the CalcArguments of Astrogator JScript, Matlab, Perl, and VBScript calculation objects are linked to a version in the component browser or embedded.

Aviator

• The usability of highly detailed flight envelopes has been improved for computationally intensive aerodynamic and propulsion models.
• FluentAero now generates an AERO file that is compatible with STK Aviator's Advanced Fixed Wing External Aero Data format, enabling high-fidelity Ansys CFD aerodynamics to participate in that higher-fidelity flight performance model system.
• The StraightAhead strategy now includes specific options for hold course/heading or apply no lateral accelerations.
• You can now modify the Lift Efficiency parameter on the Advanced Fixed Wing Supersonic Aerodynamics model. This can help with calibrating aerodynamic models to known data points. Aero and Propulsion contour/plotting tools were also added to the Aerodynamics and Propulsion performance models across the User, Advanced Fixed Wing, and Missile performance model systems to assist with evaluating these performance aspects across flight envelopes.
• A new check box titled "Enable low speed at high altitude" is now available for the Cruise Missile Performance Model. Selecting this box prompts Aviator to ignore aerodynamic lift considerations when computing minimum airspeed for a given flight condition. This enables you to build trajectories even if the vehicle cannot fly the specified trajectory.

Communications and Radar

• You can now specify solar flux instead of sunspot number when using the over-the-horizon (OTH) high frequency (HF) VOACAP propagation model.

  Object Model breaking change: SunSpotNumber changed to SunspotNumber.

• The ionosphere model Fortran library (IRI 2016) has been updated to the latest release by the IRIModel.org group (December 2021).
• You can now select and enable propagation models for the Communications/Radar object (Receiver, Transmitter, Antenna, and Radar) and the Communications/Radar object parent platform (Facility, Aircraft, etc.) as well as the global Scenario level (unchanged), for improved usability. In addition, two new access data providers have been created which will report the propagation models. These will be included in the link analysis for an access, the "Comm Active Prop Models," and "Radar Active Prop Models" data providers.
• You can now configure RF receivers with interference emitter sources in order to compute interference between a transmitter and receiver. Additionally, the interference-related (C/N+I, etc.) elements have been added to the LinkInformation access data provider.
• A new "Link Budget - Interference" report style is now available.
• You now have the ability to specify the type of signal polarization to be used when TIREM executes.
• HF OTH radar now includes multiple doppler analysis.
• Object model interfaces have been added for configuring object radar cross section 2D/3D graphics properties.

EOIR

• Responsiveness of the EOIR Sensor Scene has been greatly improved when animating, zooming, and scrolling.
• Ground vehicles and ships are now available as valid EOIR objects. These objects can now carry and utilize attached EOIR sensors as well as be imaged by other EOIR sensors with their own unique EOIR shape properties.
• You can now create and apply texture maps (Emissivity, Radiance, Reflectivity, and Temperature) to your EOIR configuration.

Object Model

• Object model support for Astrogator's Lambert Search and basic Lambert profiles have been added.
• The ExecElementsTimeArrayOnly method has been added to the IAgDataPrvTimeVar interface for ease of use when reporting on a data provider through the Object Model.
• The LineStyle property has been added to the IAgFmGfxContoursImpl Object Model interface for object coverage.
• Object model support for the Astrogator Lambert search profile has been added.

Documentation

These are the tutorials that have been added or significantly updated for this release:

• Wildfire imaging with STK's EOIR capability
• Finite maneuvers with STK's Astrogator capability
• State Transition Matrix (STM) primer
• Carrier to Noise Ratio in the LEO, MEO, and GEO zones
• Using Connect to plan a Predator mission
• Attitude Coverage
• L2: Air to Missile observations with EOIR
• Radar tracking and jamming
• Introduction to multifunction radar

STK 12.4 Features

General Astro

• STK now includes a new Satellite Collection object that allows you to manipulate and analyze hundreds, or even thousands of satellite objects simultaneously as one entity. The benefit of the Satellite Collection object is that it provides basic visualization, a minimal memory footprint, and efficient save and load operations. Satellite Collections can be used in standard STK analysis tools such as Coverage, Conjunction Assessment, Analyzer, Deck Access, and Communications.
• The ImportFromDB and the ImportTLEFile connect commands now allow you to filter out GP element sets that are outside the chosen analysis interval. This provides a mechanism to prevent the use of element sets that are too far away from the analysis interval to provide meaningful results.
• Two new date formats have been created (MJDsUTC and MJDsTAI) to make it easier to conduct comparisons. The new formats display a date as two values separated by a colon, where the left value is the modified Julian day number and the right value is the seconds into the day.
• A new scenario-level report, Spice BodyList, has been added to STK. The report lists the bodies loaded into SPICE, including each file's ephemeris segment and associated meta-data. Additionally, a status value is reported that defines how that segment ephemeris handles ephemeris requests in accordance with SPICE's rules of precedence.
• The Spice Files report has been updated to report any SPICE files that were loaded when the scenario was last saved, but are now missing. This is only available for scenarios saved in STK v12.4 or later.
• The name returned by the CoordAxes property of IAgVeSPICESegment has been updated from "J2000" to "J2000 (ICRF)" to more accurately reflect the actual coordinate system used by SPICE.
• The RIC graph style has been updated to label the left and right axes.

API

• Native Python plugin points have been added to STK for Access Constraints and Vector Geometry Tool Calc Scalar.

Analysis Workbench

• The Vector Geometry Tool now includes a new Rotation Vector, indicating the axis and angle of rotation between two axes.
• Equinoctial axes are now available as a reference frame in the Vector Geometry Tool. In this reference frame, the x-axis is aligned with the fiducial direction associated with equinoctial elements (sometimes denoted as fHat), the z-axis is aligned with the orbit normal, and the y-axis completes the the triad (sometimes denoted as gHat). These axes are defined for all orbits, except at 180 degrees inclination.
• A new set of axes (PassBreak) have been defined that align with the axes of the coordinate system specified by the satellite's Pass Break settings. These axes can be used in VGT constructs that reflect the satellite's Pass Break settings.
• The NTC frame is now available as an option for Trajectory Axes. Since it is also used in ODTK, it is now easier to transfer data between the two products. (The NTC frame aligns the x-axis with velocity and the z-axis with the cross product of position and velocity.)
• IGRF and WMM magnetic field model coefficients are now stored in an external text file (C:\ProgramData\AGI\STK\DynamicEarthData). So now when a new model is released, you can update the file directly without having to wait for a new release.
• The STKExternal ephemeris (*.e) and VectorData (*.vd) file readers have been updated to enable them to read a ComputeVelocity setting, even if the file doesn't contain rate information. By default, the velocity is computed as the derivative of the interpolating polynomial for position (consistent with previous behavior) unless the ComputeVelocity setting is set to some other value. This enables generation of non-zero velocity when the interpolation order in the file is set to zero.
• A new calculation scalar, Vector Component, has been added to Analysis Workbench. Its value is the specified component (X, Y, Z, -X, -Y, -Z) of the vector when it is resolved into a specified set of axes.

Astrogator

• Usage of SNOPT now requires a complimentary license. Please contact AGI Support if you require such a license for use with Astrogator.
• The Lambert Profile has been added to Astrogator's target sequences. Additionally, Lambert Search Profiles was added to help find the most fuel-efficient Lambert arc in the specified range of departure and arrival times.
• STK now contains new CalcObjects to report relative motion using curvilinear coordinates (i.e., downrange, crossrange, and crosstrack) that measure relative to a reference ellipse. This can assist in measuring rendezvous and proximity operations, for example.
• You can now reinitialize the state transition matrix at the start of an Astrogator segment, and propagate it through finite maneuvers.
• Astrogator now includes the ability to set the Radiation Pressure Area and Ck coefficient from the RPO Update Spacecraft Parameters sequence.
• Astrogator now reports values for DragArea, SRPArea, Cd, and Cr for the built-in N-Plate and Variable Area models as applicable. This is done via scalar projections of the associated vector accelerations in order to produce the relevant calculation objects.
• For enhanced usability, a user-defined pick string can now be specified when using Custom Intervals for vehicle graphics. This pick string is appended to the instance name when a vehicle orbit/route/trajectory is clicked on in the 2D or 3D Graphics window. Astrogator automatically populates the pick string with each segment's name when the mission control sequence is run.

Communications

• STK now integrates with Spectral Science Inc.'s MODTRAN atmospheric model for optical, infrared, and ultra-violet frequencies.
• STK now includes a user-supplied "Noise Temperature" compute plugin. This plugin is provided with the dynamic STK object data, such as position, velocity and the object attitude information.
• The ionospheric IRI model has been updated to the 2020 release of the IRI-2016 model code.

Aviator

• Inertia modeling has been added to Aviator, along with dynamics/moments strategies. These tools can be used to better evaluate the maneuverability of flight vehicles.

3D Graphics

• STK now supports the visualization of instanced 3D Tiles geometry, a common 3D Tile representation for repeated geometry, such as trees or lamp posts lining a street.
• STK modeling now makes use of the KHR_texture_basisu extension for texture compression, which reduces GPU memory requirements and improves performance.
• You can now visualize large point cloud datasets using 3D Tiles, and tilesets can be styled with resizing, translucency, and outline effects.
• STK now includes the ability to overlay the shadows of multiple planetary bodies on an object. For example, you could visualize the Earth's umbra and penumbra on a spacecraft when it is also in the shadow of the moon.

Licensing

• STK 12.4 now officially supports the use of the Sentinel HL USB dongle for licensing.

General

• The install now includes a plugin to Ansys Discovery and Ansys SpaceClaim. This provides a seamless method for converting detailed CAD models into the glTF format preferred for STK.
• You can now enable/disable the horizontal banding in Time XY, XY, and Interval graph types.
• You now have the ability to load objects into STK via a Connect command, using the URL of the object located on the SDF.
• STK has adopted the Ansys Privacy Policy. In places where the privacy policy had previously been displayed as a text document, a dialog now appears with a clickable link to the Ansys Privacy Policy at www.ansys.com, as well as the specific URL to support users that don't have a current internet connection.

User Interface

• The Object Browser now saves its state so that it remembers the open/closed state of objects.
• You can now create folders in the Object Browser in order to group STK objects.
• STK now supports uploading and downloading component versions from the Component Browser to an SDF server. This allows user to more easily share revisions of components across multiple desktops and instances of STK.
• STK now includes a more modernized UI framework and an overhaul of the icon UX. This also includes new tree group capability. Finally, the new framework also supports higher resolution buttons and improved icons.

Connect

• Two new Connect commands for dealing with SPICE files have been added (Spice, Spice_RM). These commands allow programmatic loading, unloading, and re-ordering of SPICE files.
• A new Connect command to Load the GPS Constellation has been added.
• The Collection_RM Connect command was added for the SatelliteCollection object.
• The Walker Connect command has deprecated two keywords (InterPlaneTrueAnomalyIncrement, RAANIncrement). The replacement keywords are InterPlanePhaseAngle and RAANSpacing. This changes makes them consistent with the terms used in the user interface. They retain the same meaning as before.
• An optional keyword, NameStyle, has been added to the ImportFromDB Satellite and ImportTLEFile Connect commands to control the naming of the satellites created by these commands.

Documentation

• New Astrogator tutorial that uses the new Lambert Profile and Lambert Search Profile capabilities
• New Urban Propagation tutorial
• L1 Fundamentals tutorial videos have been updated and are available online.
• New L2 exercises:
• Advanced Coverage
• AzEl Mask tool with Volumetrics
• Introduction to Advanced CAT tool
• Analysis Workbench
• New Aviator and Analyzer tutorial. This tutorial is only available if you have Analyzer installed
• Large Constellation tutorial updated with new 12.4 features
• Updated the Modeling near-real-time relays in STK tutorial

STK 12.3 Features

Licensing

• We've significantly reduced the number of product licenses associated with STK. Now you can decide if your needs are air-based, space-based, or multidomain. Whether you choose STK Pro, STK Premium (Air or Space), or STK Enterprise, you'll have a wide range of capabilities that address your design and analysis goals. To learn more, see our Announcements page.

Communications

• The Scalable Networks Modeling Interface has the added capability to configure wired interfaces associated with Facility, Place, and Target objects in STK. The wired interfaces can then be added to wired subnets or wired links and written to the EXata/QualNet configuration file for inclusion in the co-simulation between STK and EXata/QualNet.
• The Scalable Networks Modeling Interface can now be fully configured, for the Scenario Explorer and Config Importer workflows, using the Connect automation interface.
• The Scalable Networks Modeling Interface includes a new feature which adds a new default wireless interface to a node in the Scenario Explorer when an Antenna object is added to the associated object in STK.
• The Scalable Networks Modeling Interface includes a new feature which adds a new default wired interface to a node in the Scenario Explorer when a Facility, Place, or Target object is added to the STK scenario.
• The Scalable Networks Modeling Interface Scenario Explorer network settings that are associated with objects in STK (Antenna, Facility, etc.) are retained when the STK object is cut/copied and pasted in the STK Object Browser. Before this change, those settings would have been lost.

General Astro

• The Launch Window Analysis tool has been improved to better detect the minimum range and time of launch for minimum range in cases where more than one local range minimum occurs along the launch trajectory.

MATLAB

• STK MATLAB connectors now support MATLAB R2021a. Download v1.0.16 from support.agi.com.

STK 12.2 Features

Astrogator

• For STK Astrogator users, having full examples of operationally relevant sequences, such as Rendezvous and Proximity Operations is highly advantageous. It can make getting started exponentially faster and more effective. STK Astrogator 12.2 includes numerous RPO sequences and documentation on how to use them.
• Cartesian state transition matrix (STM) eigenvalues and eigenvectors have been made available for use with Astrogator. Hermitian interpolation and other computational mechanisms have been added to perform the associated calculations, new custom reports are available for the associated values and ancillary data is now stored with the scenario.
• The format used to save Astrogator vehicles and components has been updated from BCXML to standard XML to match the format already used elsewhere in STK and ODTK.
• Astrogator ephemeris interpolation and lookup speed has been dramatically improved in cases involving large numbers of segments.
• Drag plugins (interfaces IAgAsDragModelResultRegister, IAgAsDragModelResult, and IAgAsDragModelResultRegisterEval) and SRP plugins (interfaces IAgAsLightReflectionResultRegister, IAgAsLightReflectionResult, and IAgAsLightReflectionResultEval) have been updated to allow access to User Variables set in Astrogator satellites.
• The Cartesian STM folder for the Astrogator Maneuver Ephemeris Block Final, Astrogator Maneuver Ephemeris Block History, and Astrogator Maneuver Ephemeris Block Initial data providers in the Report Manager for a Satellite object have been removed. Currently, the Cartesian state transition matrix (STM) is not updated during a maneuver, so the values reported were simply the values of the STM for the segment prior to the maneuver.

Aviator

• The Advanced Fixed Wing Flight Envelope Tool now contains a AOA (Angle of Attack The angle between the body X axis and the projection of the velocity vector onto the body XZ plane. The velocity vector is the velocity of the object as observed in the object's central body fixed coordinate system.) parameter, enabling you to define a set of speed, altitude, and AOA values to cover your desired envelope using the values for AOA from analytical performance models to jump start your analysis.
• An option to control Basic Maneuver stopping conditions for the Earth surface is added. Previous versions supported the terrain surface only. This feature adds MSL and WGS84 surfaces as stopping conditions. One of the benefits of this is modeling splashdowns that truly fly all the way to the MSL surface instead of slightly different altitudes due to variations in terrain data.
• The integration system in Aviator has been updated. In addition to the previous adaptive time step integrator (RK45), a new fixed time step integrator (RK4) has been added that allows for faster performance in exchange for no error control. You can now select which numerical integrator to use for a given procedure.
• The Pitch3D and Ballistic3D strategies now contain earth frame (Compensate for wind) and wind frame (Wind pushes vehicle) guidance modes. The Compensate for wind Control Mode compensates for wind effects, while the wind frame mode results in the wind pushing the vehicle off the earth frame course.
• The Ballistic3D strategy is a 3D strategy that flies a zero G trajectory. It enables you to specify the aircraft's airspeed control and includes a mode for modeling parachute descents.

Communications

• In order to provide an initial ability to assess laser communications through the Earth's atmosphere, STK 12.2 takes advantage of the existing MODTRAN-based propagation model that has been successfully deployed by STK EOIR. This represents a precursor to a full-on integration with the MODTRAN software in a future STK release. In the interim, users are now able to access a higher fidelity propagation loss model by taking advantage of MODTRAN generated database when modeling laser communications links (infrared, visual, and ultraviolet). The MODTRAN output parameters currently being utilized includes transmittance. More information about EOIR's MODTRAN-based atmospheric database can be found at: https://agi.widencollective.com/portals/zayjeqv3/eoirresources
• There are times when a receiver has a choice of connecting to multiple transmitters, and the closest transmitter may not always provide the best signal. So when modeling communications system links you might want to select a transmitter based on more conditions than just geometry. These conditions can include terrain, antenna pointing direction, transmit power, directional gain patterns, the amount of noise in the environment, etc.
  Previously, STK would only allow you to select a link based on simple geometry, such as minimum range and maximum elevation angle. With STK 12.2, you can now select links based on an RF metric: Maximum Received Isotropic Power (RIP) or Maximum Carrier to Noise Ratio (C/N).
• Propagation models can now be selected and enabled for the Communications/Radar object (Receiver, Transmitter, Antenna, and Radar), the Communications/Radar object parent platform (Facility, Aircraft etc.) as well as the global Scenario level (as before) for improved usability. In addition, two new access data providers have been created which will report the propagation models which are included in the link analysis for an access, the "Comm Active Prop Models" and "Radar Active Prop Models" data providers.

Radar

• STK Radar offers an option to import Ansys HFSS produced complex Radar Cross Section (RCS) data in CSV file format. STK reads a CSV file for each of the signal primary polarization and cross polarization channels. It merges the data to build a complex scattering RCS matrix for scenarios in STK.

Python Environment

• You can now use Jupyter Notebook directly inside STK. This enables you to use the powerful and easy to use Python scripting language to automate STK from Windows , streamline your workflow, and provide a more interactive development experience. The Python API has also been expanded to support STK events and to expose the globe and map controls, allowing you to develop custom applications in Python.

General Astro

• STK's support of SGP4, and the GP data used with it, has been updated in several ways:
  • STK may be configured to use version 8.0 of the US Air Force Astrodynamics Standards SGP4 routine, as made available through the www.space-track.org website. The routine is provided as a library, not source code. Additional installation setup is required: contact support to obtain an FAQ with instructions.
  • GP data in the US Air Force Astrodynamics Standards TLE CSV format is now supported, in addition to the OMM-based CSV file formats that were previously supported.
  • STK now checks the GP data to ensure that it is compatible with SGP4 before using it. This is now necessary because the US Air Force has announced GP data may now be formatted for use either by SGP4 or by SGP4-XP, but not both. While STK is unable to natively propagate using SGP4-XP, it may be accessed by installing the US Air Force Astrodynamics Standards SGP4 routine that also supports SGP4-XP.
  • The GenerateTLE tool has been updated to use the default SGP4 routine as specified under Edit -> Preferences for Propagator Defaults under SGP4. In addition, the SGP4-XP algorithm can be used when generating the TLE when the US Air Force Astrodynamics Standards SGP4 routine has been installed and selected.
  • The DeckAccess Tool has been updated to allow use of SGP4 plugin routines (like CloseApproach tool, the GenerateTLE tool, and other tools). It now defaults to use the SGP4 routine set in Edit - Preferences Propagator Defaults for SGP4.
• Two new local dates formats have been added (LTZG and ISO-LTZ) to report local times using a timezone format expressed as an offset from UTC, e.g., 1 Nov 2020 01:30:00-07:00 where -07:00 is the offset from UTC (in the example meaning 7 hrs behind UTC).
• Solar Panel Tool now uses central body terrain in the solar intensity and power calculations when an STK object is configured to use terrain in its lighting calculations.

Visualization

• STK movie-makers are able to output videos using the latest format standards, including H.264 and ProRes. This is included in the Movie Timeline tool, the STK GUI, and in the Connect interface.
• glTF 3D models now support "morph targets" which allows a mesh of a particular shape to smoothly morph into a different shape.
• The STK 3D Graphics PolylinePrimitive now supports TimeIntervals to hide/show individual lines at specified times.
• STK Movie Making is faster. The Movie Timeline Wizard can now use parallel computing to scale recording operations for 3D windows across multiple cores and machines.

Large Constellation

• The emergence of mega-constellations creates new analysis challenges that are more tractably thought of in terms of a collective as opposed to considering many satellites individually. Working with hundreds, thousands or even tens of thousands of satellites and associated sub-systems can be daunting, strain the capabilities of analysis tools and lead to scenarios where the analysis goals are obscured by the sheer volume of objects. As a first step in improving analyses involving large numbers of objects, STK 12.2 introduces the Satellite Collection object which can be used to represent an entire constellation of satellites in a single scenario entity. Providing basic visualization, a minimal memory footprint and efficient save and load operations, Satellite Collections can be used in standard STK analysis tools such as Coverage, Conjunction Assessment, Deck Access, and Communications Systems Analysis.

User Interface

• The Component Browser user interface has been greatly improved for usability. It now consists of a resizable tree and grid panes separated by a splitter bar, with bitmap buttons to perform functions (e.g. Duplicate, View Properties, Import, Export, Delete). Source and File Path columns have been added to the grid, and tooltips are available on grid cells so that long User Comment, Description, and File Path entries can be easily viewed if text length exceeds the visible column width. A Filter button has been added to allow the user to select one or more Source types to display or filter out of the displayed grid entries, and Table Column button allows users to hide or show columns in the grid.

API

• A pair of connect commands have been added to return the local time zone name that has been set (GetLocalTimeZoneName_R) and set the local time zone by name (SetLocalTimeZoneName).
• The Connect command used to allow coverage to use a shapefile for its grid definition ("Cov covDefnPath Grid") now properly supports polyline shapefiles.
• The "Time Array" animation mode is now supported by the STK Object Model.
• STK Object Model event notifications have been added for the start, stop, apply and canceling of 3D editing.
• The ability to load a scenario from the SDF via the STK Object Model is now possible via the new methods LoadVDFFromSDF and LoadVDFFromSDFWithVersion in the IAgStkObjectRoot interface.
• Cut, Copy, and Paste Events have been added to the STK Object Model in the IAgStkObjectRootEvents Interface.

STK Parallel Computing Server

• You can run parallel processing on Linux using STK Parallel Computing Server. Using the SDKs (Java, Python, C#), you can now create custom applications to add scalability to STK Components, STK Engine on Linux, or ODTK Runtime computations.

EOIR

• The ease of use for large sensor and multiband modeling and simulation is improved. Now in one scenario there can be up to 16 EOIR sensors.
• Connect commands are added to save specific bands of data when creating images or saving raw data for sensors.
• The EOIR Shape Connect command is updated to match UI functionality and improve automation.

Analysis Workbench

• The Vector and CalcScalar Derivative components in AWB have been updated so that the user can force the use of numerical differences in the derivative computation. Previously, the derivative's value was always computed using analytic formulas based and the time differencing step was only used to compute the rate of the derivative. With the flag set to true, the value of the derivative is computed using numerical differencing.

Reports and Graphs

• The Boresight Intersection Lighting data provider has been updated to allow reporting all conditions (Sunlight, Penumbra, Umbra) together in the same listing of intervals, with the corresponding Condition for each interval also provided.

STK Enterprise Data Services

• SDF view of the file dialog and SDF related Connect commands have been updated to accept the web browser URL as input.
• Access to AGI's public STK Data Federate server (SDF) or Geospatial server (GCS) has been made easier by no longer requiring the loopback interface (IPv4 localhost or 127.0.0.1, IPv6 [::1]) to be added to the proxy exception list when running STK in environments with a proxy. STK now uses implicit proxy bypass rules that match URLs with the host portion being either localhost or a link-local IP address. See Online Operations in the help for details.
• When opening a file from the SDF, you can now right-click and select Copy URL to Clipboard, which copies the file's SDF location. You can also right-click the file and select Open URL in Web Browser. To support this enhancement, the SDFLoad Connect Command has been updated to enable you to load the file from SDF using the file's SDF URL.

Terrain and Imagery

• The stand alone terrain converter now takes additional terrain sources as input to allow for more accurate conversion of native terrain sources to pdtt files around the edges of the terrain source, especially for cell-centered terrain sources such as PDS (MOLA).

MATLAB Interface

• STK MATLAB connectors now support MATLAB R2020b.

Data

• All dynamic data (EOP.txt, Satellite databases, GPS Almanac data, Space Weather, etc) has been updated.

Documentation

• New Level 1 training.
• New features tutorials are now part of the help:
• Rendezvous and Proximity Operations
• Laser Communications
• Python Jypter Notebooks UI
• Comm System Object
• GPS Jamming

STK 12.1 Features

Communications and Radar

• You can now perform Over the Horizon (OTH) HF propagation modeling with the integrated VOACAP model.
• Antennas in STK Communications and STK Radar now support Ticra GRASP antenna data format.
• For the Ascii Data Beam/Null Direction Provider, you can now specify the azimuth/elevation angles in different angular coordinate systems.
• The "QualNet Interface for STK Communications" has been renamed to "Scalable Networks Modeling Interface" to reflect the fact that the interface now natively supports both the QualNet network simulator and the EXata network simulator products from Scalable Networks Technolgies.
• TIREM code has been updated to the latest version — 5.50 — in STK. It is the default version. The older version — 3.31 — is available in the previous versions folder.

Aviator

• You can now apply plugin thermal performance models that employ a variety of standard techniques to determine heat flux, heat load, and wall temperatures for any Aviator trajectory (including external ephemeris with the VGTPoint procedure).
• The Basic Maneuver Guidance and Control strategies now accept measurement noise and track estimation plugins that link to other object's dynamic state.
• You can now create STK objects from airports, navaids, and VTOL points.
• Added a scramjet propulsion model for Missiles and for User Aircraft. The model supports a plugin fuel model and provides hydrocarbon and hydrogen models. The model also supports a rocket booster mode.
• The High Fast thrust vectoring lift and thrust model is now available for Missiles. This set of aerodynamic and propulsion models was released in STK 12 for User Aircraft.
• You can now specify the amount of throttle used in the Advanced Climb and Advanced Takeoff performance models.
• Added Powered Cruise features to the Glide and Midcourse Glide guidance and control strategies.
• Added an ISP fuel flow mode to the Simple Missile Propulsion model so that you can specify fuel flow.
• Added Reynolds Number and associated viscosity values to data providers for Aviator aircraft, missile objects, non-Aviator aircraft and launch vehicles. You can use this information to inform the production of high fidelity aerodynamics models.
• The Aviator Object Model has been updated and extended to include more features in Aviator.
• Added Circular Orbit ECF Speed and related data elements to the Aviator Profile, ProfileData and STKDataProviders.
• Added a feature to copy and paste Basic Maneuver thrust and fuel flow models, making it easier to construct sequences that reuse these models.

EOIR

• Added EOIR capabilities to STK Engine that enable you to configure EOIR sensors, compute metrics, and save generated scene images through the API in your Engine application. You can also parallelize Engine application runs in STK Analyzer.
• Added the WindowEOIR Connect command, which you can use to configure the EOIR Synthetic Scene window.
• You can now create a Windows user environment variable to speed up or improve EOIR image fidelity. The user environment variable AGI_EOIR_SENSOR_OSF can have the potential values: 1, 2, 4, 8, 16, and 32. Each of these specifies how EOIR sensors will over-sample spatial data, resulting in differences in both performance and fidelity.
• You can now add and modify multiple datasets — along with their radiance, emissivity, and temperature values — from the EOIR Cloud UI dialog box.
• Added summary data to the EOIR Sensor-To-Target-Metrics data provider.

Astrogator

• Added a model that enables file-based specification of an N-Plate model for use in computing atmospheric drag. This model has been included to match the model available in ODTK.
• The user interface of the Astrogator Scripting Tool windowing system for sequence scripting tools and target sequence scripting tool profiles has been improved.
• Added models that enable you to specify a time-history of varying cross-sectional area for the purposes of computing atmospheric drag and solar radiation pressure. These models have been added to match those available in ODTK.

3D Graphics

• 3D Models in glTF and GLB format can now be deformed by virtual "skin and bones" armatures, enabling organic movements and animation.
• Added support for driving glTF animations with STK articulations.
• Added a new ocean rendering system that features fully animated waves.
• Revised the 3D Measure tool to improve usability and consistency with STK. 3D Measuring now reports range and bearing readouts of central body surface measurements at the position of the mouse cursor. It uses the unit settings specified in the Scenario Units properties panel.
• Added support for the EXT_mesh_gpu_instancing extension in glTF models.
• Added support for glTG 3D models containing the KHR_texture_transform extension and TEXCOORD_1 coordinates.
• You can now render glTF models and 3D Tiles tilesets on computers with limited graphics capability, supporting hardware back to OpenGL 1.1.

Access

• The Access Data data provider now reports Min/Max constraint values in the Start/Stop Constraint Definition elements, as appropriate. In earlier versions of STK, the only time that a value was reported for these elements was when a constraint had special data settings.
• The CentralAngle and CentralDistance constraints are now available for vehicles and ground locations. These constraints provide a simple measure of physical separation using the angle between the position vectors, or that angle multiplied by the maximum radius of the central body (of the object owning the constraint).
• The Two-Ray RF environment model now works on central bodies other than Earth, such as the Moon or Mars, as long as both transmit and receive terminals are on the same central body surface and satisfy the basic conditions of low antenna heights and short distances.
• The Access Violated Constraints and Access Detailed reports are now easier to read because the alignment of their columns has been improved. If you need to use these report styles as they were previously configured, you can simply edit the styles accordingly and save them in your local area; this overrides the installed styles.
• Added options that enable you to change animation access line widths.

Analysis Workbench

• Analysis Workbench File Calculation Scalar components now have an embedded Time Array component which exposes the native times of the data in the .csc file.
• Analysis Workbench now automatically computes a time component, "GapIntervals," that indicates the time intervals during the computation span in which no access occurs. This is defined as the complement of the intervals provided by "AccessIntervals" with respect to the ConsiderTimeSpan (i.e., the time interval over which the computation was attempted). Note that while the intervals contained in "AccessIntervals" have the property that all constraints are met at both interval.start and interval.stop, the intervals in "GapIntervals" have start and stop times that actually satisfy the constraint for a duration less than the time tolerance of the computation. Outside the edge effects, the times within the "GapIntervals" do not satisfy all imposed constraints.

Connect

• In the Chains Connect command, you can now use wildcards in paths when adding or removing objects.
• Added the option, "ShowPoints," to the VO Primitive Connect command for Circle, Rectangle, Ellipse, and Sector primitive types.
• Added support for CCSDS OPM messages (versions 1.0 and 2.0), in KVN format for import and export, to the InitialState Connect command.
• You can now specify the step size to report messages with when you use the UseStartStop option with the InitialState Export command to report messages over a requested time interval.
• The SetAttitude Connect command now clears all attitude override segments created by Astrogator using the ClearData AllAstrogator option.

Data

• All dynamic data (EOP.txt, Satellite databases, GPS Almanac data, Space Weather, etc) has been updated.

Documentation

• New tutorials have been added to the help:
• Evaluate HF Communication Links — Learn how to use the new VOACAP feature.
• Analyzer and the Multifunction Radar Object — Learn how to use Multifunction with Analyzer.
• Evaluation Communication Links — New L2 Advanced Communications lesson.
• Model Aircraft Missions with Aviator — New L2 Advanced Aviator lesson.
• Using the SDF to Store, Collaborate, and Share your Work — Learn how to use SDF.
• The following tutorials have significant updates:
• Using the Scalable Network Modeling Interface to Analyze Communications Network Performance —interface renamed and updated for 12.1.
• Digital Mission Engineering (DME): Hypersonics and EOIR — added new Hypersonic thermal load analysis feature walkthrough.
• Getting Started with Python — Updated the lesson to include the API.

General

• All component selectors in STK Communications and STK Radar have been updated to enable both "Linked" and "Unlinked" reference types.
• Added a new animation mode ("Time Array" mode) that enames animation to use an Analysis Workbench Time Array component as the source of animation times.
• Changed the minimum animation time step to 1 microsecond.
• Created an ephemeris file reader plugin that reads CSpOC eci files as described in the ephemeris file PDF.
• Accelerated report generation and other computations in some cases by throttling the percent complete updates. The most significant impact is on computations with a large number of fast to compute iterations.
• STK now displays a warning dialog when it starts if it detects multiple graphics cards.

General Astro

• When you use OPM message data to set the initial state — using either the Initial State button on the Satellite's Basic properties or the InitialState connect command— it will now update position-velocity covariance elements for satellites that use the HPOP propagator. And if you export OPM data from an HPOP satellite that uses covariance, it will output the covariance in the OPM message data.
• The CCSDS_OPM format for the Initial State Tool has been updated to support the XML format of the CCSDS OPM file (version 2.0).
• The CCSDS OMM message (in XML and KVN formats) is now supported by STK in places that normally require a TLE file input. Only OMM files supporting SGP4 content are supported.
• The Element Set data provider for Satellites now enables you to report GP data in two line element (TLE) format and CCSDS OMM, in XML and KVN formats.
• Added a new interface, IAgAsDensityModelPluginExtended, that adds three new callbacks to the standard IAgAsDensityModelPlugin interface, for the times when the numerical integrator (i) starts computation (PreCompute()); (ii) starts a new integration step (PreNextStep()); and (iii) ends its computation (PostCompute()).
• The interfaces used with density model plugins IAgAsDensityModelResultEval and IAgAsDensityModelResult will now report flux values when you have chosen constant values for flux rather than using a file.
• Vesta is now available as a central body using data from JPL's Dawn mission.
• When reporting in AdvCAT, the value of 'Type' now reports 'GPElem File' instead of 'TLE File' to better reflect that the file contains GP elements, whether formatted as a TLE (two-line element) or not.
• Added new keywords to provide more flexibility in STK External Ephemeris files (i.e., *.e files) for setting the reference frame used by the covariance data in the file, including the use of AWB coordinate Systems.
• In tools that load TLE files (DeckAccess, AdvCAT, CloseApproach, LaunchWindow, LaserCAT, RFI, MTO), when the file contains more than one element set for an SSC, each TLE is now considered separately in the computation, though they have the same SSC number.
• The Date() and Date_Array() methods of the IAgAsDensityModelResultEval, IAgAsDragModelResult, and IAgAsDragModelResultEval interfaces have been deprecated, since they report Month using a 0 index, not a 1 index (so that January is 0, and May is 4). Plugins should instead use DateElements() or DateElements_Array() that report Month normally (January is 1, May is 5).
• A new optional keyword has been added to the gravity field file format to allow for specification of the central body fixed reference frame to be used for gravity field evaluations. This keyword has been added to the lunar gravity field files for Lunar Prospector and GRAIL derived gravity fields and overrides the FixedFrameForGravity setting in the Moon.cb file.

Install

• The QualNet Interface for STK Communications is now known as the Scalable Network Modeling Interface and is again available as an option when you install STK from the DVD install image.
• You can now install STK Engine Resources from the STK Engine Resources DVD.

MATLAB Interface

• STK MATLAB connectors now support MATLAB R2020a.

Object Model

• You can now access the glTF settings of an object's VO Model with the IAgVOModelGltfImageBased interface.
• You can now access drag model plugins with the IAgVADragModelPlugin interface.
• A multi-platform Python API has been released.

Reports & Graphs

• Added the keyword ReferenceEpochFormat to External Data Files so that you can use time formats other than UTCG to specify the epoch for data used in the User Supplied Data data provider.
• You can now invert axes scale for XY type graphs. The X axis increases in value from right to left and the Y axis from top to bottom.
• The position covariance matrix is now available from several data providers in AdvCAT, derived from each object's ellipsoid setting (treating the ellipsoid's orientation and unscaled size as being the 1-sigma uncertainty ellipsoid for the corresponding position covariance matrix).
• Added a Name element to the LaserCAT Potential Victim and the RFI Potential Victim data providers so that they can support letters in the SSC field in TLEs and distinguish TLEs (with different epochs) for the same SSC, when using files containing multiple TLEs for the same SSC.
• The "TLE Summary Data" data provider, used with the Generate TLE Tool, can now output a description of the individual SGP4 elements and the CCSDS OMM message in XML or KVN formats.
• Added the position-velocity covariance matrix values as data available from the Pos Vel Projected Covariance and Pos Vel Rotated Covariance data providers.

STK Data Federate

• Added an option on the General Preferences page, "Default to Browse view when opening a file from the SDF", which enables you to specify the default view when you open a file from the SDF.

User Interface

• You can now resize the Export Shapefile window so that items in the export list are visible.

Volumetrics

• You can now create volumetric grids relative to terrain height or mean sea level.

Communications

• Script Plugin file selectors now filter Python files and show files with *.py suffix.

EOIR

• You can now save the contents of an EOIR synthetic scene as a bitmap using the EOIRDetails Connect command.

Install

• The .Net Framework installed with STK has been updated to v4.7.3081.

New MATLAB Connector

• STK MATLAB connectors now support MATLAB R2020a.

Aviator

• Aviator has gone through extensive improvements to its underlying physics engine, resulting in fourth generation aircraft modeling for support of real world flight, especially at extreme velocities.
  • Basic Maneuvers use a full 3D gravity model with oblate rotating earth effects, including Coriolis effects. They propagate using 6DOF dynamics referenced to the local coordinate frames of the strategies involved. For backwards compatibility, some strategies can automatically compensate for the Coriolis effects.
  • Standard procedures use a round earth model with gravity as a function of altitude. This model also includes Coriolis acceleration effects on the apparent accelerations required to fly the specified trajectory. Trajectories are constructed in the ECF frame, and the resulting body frame accelerations account for the higher fidelity models.
  • Because of these new Earth models, all calculations related to accelerations and ground speed, air speed, and ECF speed may produce different results in STK 12 than they did in earlier versions. Wind effects also reflect the differences that arise from these new Earth models. Since Aviator is primarily oriented to aeronautical concepts, air speeds behave similarly across all generations.
  • While some computations may permit higher and faster flight in some non-steady state conditions, the limits on speed and altitude entries on user interface fields are 7 km/sec for max speed and 1,000 km for altitude. These limits permit analysis at Mach The ratio of the aircraft's speed and the speed of sound at the aircraft's altitude, with local atmospheric conditions. numbers greater than 20 at any altitude less than 350 Kft and greater than 10 at 500 Kft (temperature starts increasing rapidly above 350 Kft, which leads to increasing speed of sound). The limits have been selected to preclude orbital flight conditions - flying "straight and level" at the max velocity at max altitude results in a load factor relative to sea level force of gravity of about 0.38 g.
• Aviator now has a rich API via the STK Object Model. You can use the API to automatically configure a mission and generate routes. You can also access the Aviator Catalog to automatically configure aircraft and other catalog items. Documentation and code snippets for Aviator have been included in the STK Programming Help, as wells as, several example scripts in the install.
• Enhancements have been made to the Advanced Fixed Wing tool for easier calibrations of the performance models to known aircraft performance.
  • The fuel calibration for the empirical powerplant models includes an option to specify the TSFC at a specified operating point.
  • Thrust Required and TSFC contours are provided on the Flight Envelope alongside the existing Thrust Available, Fuel Flow, and Specific Range contours to facilitate the calibration activity.
• Added the Aviator Atmosphere model to the MATLAB aeroToolbox. This makes it simple to use the model within scripts or other free-form MATLAB activities.
• Added a Lambert Midcourse guidance strategy to the Aviator Prop Nav feature. This strategy generates and updates the trajectory as the geometry and target/interceptor speeds evolve in order to command a zero G flyout. You can specify maneuverability limitations and make use of target acceleration models similar to the standard 3D Guidance strategy. The existing 3D guidance strategy has several simple ballistic shaping modes and this new strategy is considered a major high fidelity upgrade to that capability.

EOIR

• EOIR now has a thin layer cloud modeling approach that is accessible through Connect commands or a GUI. The cloud model is extremely flexible with inputs for multiple time-dynamic layers and cloud characteristics such as percent cloud cover, temperature, emissivity, and radiance. The model allows for integration with community standard cloud modeling file, which can also be displayed in STK's 3D Graphics window.
• STK EOIR has undergone a major architectural overhaul for STK 12. This capability has moved from a UI plugin architecture to be part of the core STK. This has improved performance and will enable future improvements to usability, computational calculations as well as better integration with STK's object model and Connect API's and integration with Analyzer for trade studies.

Communications and Radar

• STK now supports import of ffd format complex data antenna gain patterns. These patterns may be produced by ANSYS HFSS program. The antenna data file may have multiple gain patterns. Each gain pattern corresponds to a different frequency. STK will first search for the pattern with a frequency closer to the signal frequency and will use that pattern to compute the link or graphics gain values.
• Cosecant Squared (gain pattern) antenna model has been updated to offer an option for the sidelobe type. Users may choose from a constant value sidelobe or Parabolic, Square Horn or Sinc type patterns.
• Antenna, Transmitter, Receiver, Radar, and vehicle RCS contour lines now display on top of terrain in 3D when not displayed at altitude.

Access

• STK 12 adds the ability to include 3DTileset geometry (e.g., massive city models, photogrammetry, etc) computationally in your analysis. A new constraint, 3DTiles Mask, has been added to the Facility, Target, and Place objects, as well as all vehicle types. This allows for 3D Tileset geometry to obstruct visibility when computing access. 3D Titleset hosted in GCS, Cesium ion or from the local filesystem, can all be used for analysis with this new constraint.
• The Access Configuration data provider has been expanded to report more computational settings, including the set of constraints used in the computation and the set of ignored constraints.
• Accesses now (by default) save their derived data (i.e., satisfaction intervals) when the Scenario is saved so that the Access need not be recomputed on Scenario load. Previously, only the definitional data for Accesses were saved and the access computations were performed during Scenario load. Each Access stores a setting (Saved Computed Data) that controls this behavior. Simply using the loaded derived data and avoiding recomputation usually produces the correct results; however, if the objects involved in an Access were separately saved, apart from the Scenario, then the derived data could be out-of-sync with the object’s data and a recomputation would produced different results than were loaded. In such a case, set the Access to not save its derived data. Default behavior can be controlled using settings on the Access Defaults tab of Edit->Preferences.
• Reporting Connect commands (e.g., ReportCreate, Report_RM, GraphCreate, etc) now work for Access objects using an Access instance path of the form */Access/accessObjectPaths where accessObjectPaths is the name of the Access as formatted in the Report tool (e.g. Facility-Facility1-To-Satellite-Satellite1).

Astrogator

• Architectural changes have been made to Astrogator to support improved product interoperability with ODTK, specifically to the following areas:
  • Astrogator engine models and related constructions have been refactored.
  • Astrogator maneuver pointing/attitude definitions and related constructions have been refactored.

  Associated plugin interfaces have been relocated and user code will require updates to account for these adjustments.

• Astrogator maneuver pointing/attitude related attributes have been consolidated into a 'Pointing' scope. Maneuver thrusting related attributes have been consolidated into a 'Thrusting' scope. All related previous attribute paths have been deprecated. While backward compatibility steps have been introduced to mitigate disruption, it is recommended that any scripting utilities that utilize maneuver attributes be updated to use the new scopes (this includes, primarily, Astrogator scripting tool instances as well as Astrogator Connect scripts).
• A calculation object to compute the CR3BP Jacobi constant has been added to the Astrogator - MultiBody calculation object set. This calculation object is valid only for Astrogator satellites propagated with an appropriately configured CR3BP propagator.
• Pi has been added as a constant in the Component Browser.
• Astrogator satellites now save pass data in the same way other propagators do to improve load performance.
• Save/Load performance has been greatly improved for long duration scenarios that contain many segments.

General Astro

• Vehicles and ground objects (Facilities/Targets/Places) can now do lighting computations that include the effects of terrain.
• Updated rotational elements have been included for the following solar system bodies in accordance with the 2015 IAU report on Cartographic Coordinates and Rotational Elements: Ceres, Deimos, Mars, Mercury, Neptune and Phobos. The updating of the rotational elements effects an update of the transformation between the central body-fixed and inertial reference frames for the affected bodies.
• STK now allows the time of the first attitude data point to be overridden with a user-specified value. This behavior is parallel to a similar feature in the StkExternal Orbit Propagator.
• The analytic elements for the major planets have been updated to match the paper "Keplerian Elements for approximate positions of the Major planets," available on a JPL website. The paper contains two tables of elements; the values from the 1800-2050 table has been used.
• The following parameters defined in the Sun.cb file have been updated:
  • the Gravitational parameter for the Sun now matches the DE430 value (the same value currently used by JPL/Horizons)
  • the Sun's radius matches the nominal solar radius defined by IAU 2015 Resolution B3
  • the Sun's luminosity matches the nominal solar luminosity defined by IAU 2015 Resolution B3. In addition, the length of the astronomical unit has been updated to match the value defined by IAU 2012 Resolution B2.

  In each case, the values have not changed substantially and differences with respect to previous STK versions should be considered as noise.

Analysis Workbench

• A Scalar Calculation that computes the dot product between two vectors has been created in the Calculation Tool. The user has the option of normalizing the vector prior to evaluating the dot product.

Parallel Computing

• The product previously known as Scalability Extension now has a new name: STK Parallel Computing Server.
• The Parallel Cluster Option is now a feature of the STK Parallel Computing Server.

Coverage

• A new Figure of Merit, System Age Of Data, has been added. This new metric measures the time elapsed since a Coverage grid point has been seen where simulated collection of grid points is subject to the same sequence of Command-Collect-Downlink events as are used in the System Response Time.

3D Graphics

• The default terrain texture cache size for new scenarios has been increased from 64 MB to 128 MB.
• glTF 3D model load time has been improved.
• glTF 3D models can now take advantage of the KHR_materials_clearcoat extension.
• STK now includes support for the SteamVR/OpenVR library, which allows compatible Virtual Reality headsets like HTC Vive, HTC Cosmos, and Valve Index to be used natively within STK.

Data

• The following STK default options have been changed in STK 12:
  • STK now is full screened when started or when a new scenario is created
  • All vehicles use a line width of two (2) pixels for groundtracks and orbits/trajectories/routes.
  • The default star collection has been modified to be Hipparcos with a maximum magnitude of 8.
• The Connect Java, Perl, and C++ samples have been moved from the /Connect to /CodeSamples/CodeSamples.zip