National Aeronautics and Space Administration

Glenn Research Center

Why is Propagation Important?

Knowledge of atmospheric propagation characteristics at a particular site provides critical information which aids in the system planning for ground-to-space communications system design and performance (i.e., link margins, availabilities, realistically supportable data rates, etc.).

As NASA and commercial satellite communications assets progress to higher frequency utilization (Ka-band and above), the expected advantages of wider spectral bandwidth can be quickly offset by the realities of increased propagation problems which can contribute to higher losses, group delay, depolarization, gaseous attenuation, and radio noise.

By characterizing these effects, performance metrics can be defined for a communications system at a particular site and fidelity of global models can be enhanced which will provide better understanding of the contribution of the atmosphere to the degradation of communications systems.

The objectives of the NASA RF Propagation Campaign are:

  • To provide a good understanding of Ka-band propagation effects
  • To develop models for the prediction of propagation-related effects
  • To develop tools for the mitigation of these effects