Primary features are:

• Ground effect calculation based on an analytical solution for spherical waves, which was extended for finite segment length and variable ground properties
• Ray tracing algorithm to take meteorological effects into account. Additional to changes on shielding effects also levels in acoustical shadow zones are predicted
• Reflection models for rigid surfaces that differentiate between coherent reflections (mirror-reflections) and scattering. The solution for the coherent part is based on the Kirchhoff-Helmholtz-Integral, the model for diffuse reflections follows the principal of exchange
• Models for diffuse reflections on forest edges and cliffs