What Is Real Propagation Research?

We all know the shortwave propagation from our home well but merely know how it is like at the other side of the path. Our logbooks and experience at home clearly show where is difficult to make contact, and most often the story ends at that point. Then our attention usually goes to improve our antenna, rigs, and so on. 

Here I am taking another approach. I place myself at "the other end" of the path. It is literally one-step-forward approach to experience the propagation by operating from "the other side". The observation data and my experience often uncover the hidden mechanisms of shortwave propagation, leading to increase the possibility of future contact by utilizing difficult paths with difficult regions. Giving out "new one" to many of you while my operations is also a big bi-effect of these real propagation research. 

For example, operating from VP9 (Bermuda) provide valuable observation data and experience on propagation with JA (Japan) which is quite difficult to make contacts. I did not only concentrate on the great-circle paths (e.g., short path and long path) but also off the great-circle paths known as skew (bent) paths. These difficult paths are quite important especially when working difficult regions. My VP9 operation revealed when the skew path will open on which band at the certain time of the year. Also, the observation suggested the promising space weather conditions as to shorth path openings. These outcome go directly to you and become one of your operation skills.

In addition, I analyze the shortwave paths that I experienced with propagation simulation tools (e.g., HF-START, VOACAP), the data from Reverse Beacon Network (RBN), and sound recordings to understand the background physical (ionospheric) mechanisms. From the analysis on ZS (South Africa)-JA propagation, for example, it became clear that nighttime Equatorial Ionospheric Anomaly (EIA) over the Indian Ocean contributes to the chordal hop of trans-equatorial propagation (TEP). HF-START visualized the path and demonstrated that the ionospheric duct propagation was evident. This can be applied not only to ZS-JA propagation, but also to 3Y/B, ZS8, ZD9-JA paths, which are the "difficult regions" from Japan. Now Japanese stations know when and what band they will see more signal enhancement made by chordal hop.

Similar propagation research can be performed at any parts of the world. Operating from Pacific Ocean on low bands will reveal the sensitive greyline effects for Europe, and operating from Indian Ocean will see the same for North America. Not only giving new one to those worked me but also giving new scientific findings to amateur radio community as a whole is the goal of this real propagation research.

Jun Maeda, Ph.D.

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