It Seems to Us: Technology and Science, A Two-Way Street
When we think of the relationship between science and technology it is usually in terms of the contributions of the former to the latter. Scientific advances give us the ability to make better tools. Tools usually mean hardware, but not always. Currently the most exciting improvements in our transceivers come from software, particularly software defined radios (SDRs). Software may be a purely intellectual product, but the ever-increasing capabilities of software that we have come to expect (and that sometimes seem to be forced upon us even if we neither want nor need them) depend on the faster microprocessors and the cheap and abundant data storage devices that are among science's end products.
But what about the contributions that technology can make to science? Specifically, what can we as radio amateurs do with our ever-more-sophisticated hardware and software to contribute to human understanding of our physical world? The answer may be, more than we think.
There is no doubt that radio amateurs currently possess the world's largest pool of experience with -- and even more important, curiosity about -- radio wave propagation. This is especially true of ionospheric propagation, which has not been of much commercial interest since the widespread deployment of communications satellites. Military interest also has waned although that trend may have begun to reverse. Academic curiosity tends to follow research grants, which have been flowing in other directions.
One natural focus of amateurs' interest is on trying to improve our ability to forecast propagation conditions. We want to know what time a particular frequency will let us reach a specific place, or what band is the best bet to bridge a specific path at a particular time of day. Another focus is on anomalous propagation: predicting or detecting unusual conditions that provide rare opportunities for long-distance (DX) communications. For the users of other services propagation anomalies are a nuisance, whereas for us they provide a reward for hours of patient monitoring in the form of contacts with new countries, states and grids.
Learning how to improve the reliability of radio communication is useful. Chasing rare contacts is both educational and fun. Occasionally amateurs have gone beyond these self-fulfilling activities and have contributed in an organized way to the science of radio propagation. Here are just a few examples.
For several years in the early 1920s, at the request of the Bureau of Standards the ARRL organized "fading tests" in which amateurs were asked to observe and report on the nature of fading on short wave signals. The results of these tests contributed to the understanding of the influences on short wave propagation.
During the 1957-1958 International Geophysical Year the ARRL collected data on VHF propagation, with an emphasis on ionospheric scattering, under a contract with the U.S. Air Force.
Over a period of decades, sporadic-E propagation events have been exhaustively analyzed by amateurs in an effort to find correlations with other natural phenomena. The quest continues for an understanding of what causes the "clouds" of intense ionization to form in the E layer.
As reported in December 2007 QST, an effort to determine whether Marconi's claim of having bridged the Atlantic by radio in 1901 was credible led to unexpected observations of long-distance daylight propagation in the medium frequency range (160 meters and the AM broadcast band).
The December 2007 QST article included an intriguing reference to the relationship between the amount of nitric oxide in the D layer -- the concentration of which is greater now than in Marconi's day -- and the daylight absorption of radio signals. The article suggested that absorption may have been less in 1901 than now, yet many amateurs have observed that during the current solar minimum DX has been better than ever on our lowest frequency bands, 160 and 80 meters, and that -- contrary to conventional wisdom and recollections of past experience -- propagation sometimes commences well before local sunset and lasts well past local sunrise. None of the current observers were around in Marconi's day, of course, but many among us have been DXing for decades and so can draw on experience gained over half or more of that time.
We know that the protective "bubble" that surrounds our planet and makes life as we know it possible is constantly changing in countless subtle ways. The history of radio encompasses just a fraction of the span of scientific observations of the sun and of environmental conditions here on earth. We tend to be obsessed with sunspots, but are there other factors whose influence on radio propagation might be detected through long-term observation? Can we put our new tools to work, collecting propagation data more comprehensively and accurately than ever before? By doing so can we contribute not only to the science of radio propagation but to environmental science as well?
David Sumner, K1ZZ
ARRL Chief Executive Officer