Time-Series Modeling and Analysis of High Frequency (HF) Vertical and Short-Path Oblique Incidence Ionospheric Soundings.

摘要

One example of a non-stationary physical process that influences communications systems can be derived from a millimeter wave link operating over a stable line-of-sight path. Such a system would encounter a rapid change in its propagation path if a heavy rainstorm suddenly disturbed the link. Another example is derived from the adverse effects on high frequency radio communications caused by sudden variations in the ionosphere. Due to the random nature of these phenomena, and due to the time-dependence of experimental information, a logical approach to forecasting these phenomena and interpreting the results seems to lie within the realm of non-stationary time-series modeling. Considering the premise that communications operational effectiveness is dependent on environmental effects, a procedural approach is recommended for characterizing ionospheric effects on High Frequency (HF) Communications utilizing time-series modeling. The recommended technique stresses the structuring of the appropriate difference equations through the criterion of minimum residual variance.