Calculate RF propagation loss over irregular terrain, and more.

The Terrain Integrated Rough Earth Model (TIREM) extension adds fidelity to RF calculations so that you can apply irregular terrain, seawater, and non-line-of-sight effects to link performance analysis in STK.

TIREM also models near-field considerations, power density and field strength equation. TIREM examines the elevation profiles and, based on the geometry, selects the optimum model for the calculations. It can also select appropriate modes of propagation for paths based on the geometry of the profile — such as multiple knife-edge diffraction and troposcatter, two physical phenomena that extend the signals propagation into beyond line-of-sight (BLOS).

Use cases

  • Analyze dynamic nodes as part of an overall system simulation.
  • Evaluate link performance.


  • The de facto standard propagation tool for the United States federal government.
  • Visualize analysis in 2D or 3D.
  • Calculating RF propagation loss over irregular terrain from 1MHz to 20 GHz.

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STK Terrain Integrated Rough Earth Model (TIREM) Spec Sheet

Detailed feature list for STK Terrain Integrated Rough Earth Model.

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