ANSYS Systems Tool Kit (STK) 13.1

ANSYS Systems Tool Kit (STK) 13.1: Digital Mission Engineering Software

STK 13.1 is the latest release of Ansys' Systems Tool Kit for digital mission engineering, enabling physics-based modeling and simulation of complex systems in realistic operational environments. It was released on March 5, 2026.

Key New Features in Version 13.1

Network Throughput Analysis

STK 13.1 extends the data rate Optimal Strand metric introduced in 13.0 to full network throughput analysis. Instead of analyzing a single optimal strand, STK now computes the total throughput capacity of a network based on designated source and destination objects, identifying which nodes are likely bottlenecks. Total network throughput and individual object usage can be visualized in 2D/3D windows and reported via Report Manager.

Circular Restricted Three-Body Problem (CR3BP)

New CR3BP analysis capabilities for modeling the dynamics of small bodies under the influence of two massive primaries (e.g., Earth-Moon or Sun-Earth systems). Users can now visualize and analyze orbit families in a Satellite Collection object using the new CR3BP type. The model is implemented in Astrogator and can be integrated with other propagator functions.

ITU-R P.676-13 Propagation Model

New propagation model supporting locally known atmospheric data (barometric pressure, temperature, water vapor density) as a function of altitude, enabling more accurate RF link analysis.

Performance & Usability Enhancements

• Astrogator Differential Corrector: 10-15% faster execution

• glTF/3DTiles Support: Mesh compression via meshopt extension; Terrain2Tiles utility outputs smaller 3DTilesets

• Point Shapefiles for Deck Access: Extended support for point Shapefiles

• Custom Access Graphics Color: Independent color selection for access graphics

New API & Object Model Interfaces

• IAgAccessCnstrNoiseTemperature: System noise temperature access constraints

• IAgAntennaHFSSDesign (and variants): New HFSS Design antenna models including Helix Quadrifilar Short, Slot Gap, Wire Dipole, and Wire Monopole

• IAgGroundLocation: Shared interface for Place, Facility, and Target objects

• IAgChStrandAnalysisOpts: Replaces IAgChOptimalStrandOpts for Chain optimal strand and network throughput computations

New Analysis Workbench Capabilities

• SurfaceNormal vector type: Computes vector normal to central body surface from a given point, optionally incorporating local terrain data

• BetaAngle(Sun) and BetaAngle(Moon): Automatically created angles for each Satellite, computing the angle between the apparent direction of the central body and the orbit plane from the satellite's actual position

• Polar-Nodal element set: Added to Orbit ParameterSet reporting radius, radius rate, transverse rate, true longitude, angular momentum magnitude, and nodal vector

TETK & ModelCenter Integration

• FMU 3.0 Support: TETK Data Displays now support FMU 3.0 files exported from Ansys SCADE Display 2026R1, enabling direct mapping of TETK Data Elements to SCADE graphical components

• Macros: Now working in the STK Plugin for ModelCenter