Fall 2003 Issue

PROPAGATION

The Fall Meteor Shower Season

By Tomas Hood,* NW7US

Radio meteor observations for November and December 2002. the horizontal axis shows the day of the month, progressing from left to right. Every five days a red vertical line is drawn. the vertical axis is the hour of the day. Brown squares indicate missing data. Note the high activity on November 19, during last year’s Leonids meteor shower. This image is provided courtesy the Astronomical Observatory, University of Ghent (http://allserv.rug.ac.be/~pdegroot/meteor/mc1_02.html).

Is it possible to predict propagation conditions and DX openings on the frequencies above 30 MHz? Are there reliable models that enable us to forecast sporadic-E, aurora, troposcatter, and other known propagation modes?

After many decades of on-the-air experience, the amateur and scientific communities are still struggling to find a practical understanding of the complex modes of propagation unique to VHF and above. While there have been decades of weak-signal and long-range (DX) operation on VHF, most of this historical information is contained in contest and special-event logs. More significantly, most of this data is sparse and the number of operators limited. There is no historical, worldwide data, simply because there hasn’t been a large enough population of VHF operators active in weak-signal long-distance DXing. The research done by the scientific community is helpful, but also limited to very specific areas. Therefore, there is a great opportunity for us amateur radio scientists to unlock the secrets of propagation on these higher frequencies.

True worldwide exploration of propagation on the amateur radio bands above 30 MHz has only recently become a reality. The number of active, on-the-air amateurs on VHF/UHF is only now reaching a level high enough to support true research of regional, national, and worldwide VHF/UHF DX. A concerted effort is under way to record daily activity worldwide. More accurate DX clusters where grid-square information is recorded for both ends of the QSO, e-mail reflectors, and on-line forums for real-time discussion of current conditions, and repositories of logs, are all ways we are increasing our knowledge. In addition, detailed geomagnetic and solar data—as well as real-time monitoring of the ionosphere, weather, and propagation—is at our disposal via the internet.

I’ve begun to organize links to existing projects, DX clusters, research results, on-line data resources, and real-time observations at my web page, <http://vhfprop.hfradio.org/>. Take a look and join the community of modern amateur scientists working toward unlocking the secrets of propagation on the bands above 30 MHz. We need as many on-the-air operators using as many modes of propagation on as many VHF and UHF bands as possible.
 

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