Ionospheric Propagation Loss Model

The propagation loss (through the Ionospheric layer) computation is based on the ITU-R P.531-13 recommendation. The total electron content (TEC) along the propagation path causes polarization rotation (due to Faraday rotation). Total electron content (TEC) is estimated by using the International Reference Ionosphere (IRI) model and integrating electron density over the actual path through the ionospheric layer.

The reference data used by the IRI model is an integral part of the model, and updates are issued by the IRI conference regularly.

STK’s computations use the 2007 version of the IRI model.

Alternate AP Data

The following fields provide the option to use alternate AP data.

Parameter	Description
UseAltenateAPFile	Overrides the built-in AP dataset.
AlternateAPDataFile	Provides the path to the user-supplied file. This file will override the ap.dat file provided by the IRI model.