Meteor Burst Communications - The Janet Program
by Peter A. Forsyth
Looking back on the "early days" of RPL, or at least that part of the early days after 1951, I realize that there was indeed a magic about the place. Things got done, ideas got generated, problems got solved with a regularity that now appears in retrospect to have been close to miraculous. Of course at the time there were worries and frustrations. There were abrasive day-to-day conflicts but underneath it all was a real feeling of confidence. Just how this confidence was generated is hard now to understand. Certainly the staff were no group of supermen. There was the usual range of competence found in any good, fairly large research organization. But most of the staff were young, and inexperienced, and most had not been trained in radio physics but were just learning to apply their particular educational backgrounds to the field of radio physics. It would be pleasant to be able to ascribe the performance of the lab at that time to a high morale, but in fact there was a more than ordinary amount of grumbling and complaining about all levels of the administrative structure and about all the "red-tape" involved, all, one might add, with little justification.
Nevertheless, perhaps in spite of the general conditions, there was this all-pervading confidence in the ability of the lab collectively to solve new problems, to come up with new approaches to old problems and at the same time to compete technologically with some of the best labs in the world. There was one unique characteristic of the lab in those days which I have not found to a similar degree anywhere else, and I have no idea whether it was cause or effect but it was certainly related to the feeling of confidence. This was the remarkable professional generosity in recognizing scientific contributions. Many of the scientific problems were solved by innumerable conversations, casual black- board discussions and coffee-time brain-storming sessions. In such an environment it would have been easy to ignore individual contributions but this did not happen. Most people were scrupulous in acknowledging sources and in drawing attention to other people's work.
There was also a pervading sense of success. Everyone seemed to believe that each problem had its solution and it would only take a little hard thought and a little hard work to find it. Of course there was not actually anything approaching uniform success but in the rapidly developing folk-lore of the lab the failures, frustrations and ambiguous results were acknowledged only as a kind of background to a successful parade of new findings.
My own initiation into this atmosphere was in 1952 after I had spent nearly a year on secondment to the University at Saskatoon and finally joined RPL in its new building at Shirley Bay. Because I had been doing VHF auroral radar work at Saskatoon I was expected to take general responsibility for the MF part of the frequency spectrum. The only big thing that was happening at the time in VHF communications was the attempt by Booker and a number of other American scientists to establish long distance communication using a very high power transmitter at Cedar Rapids, Iowa and a receiving station at Stirling, West Virginia. Before my arrival John Chapman and John Crysdale had set up a single Yagi antenna on the roof of the new building in the hope that it would detect the Cedar Rapids signal even though the highly directional transmitting array was pointed well away from the Ottawa direction and the distance (1350 km) was extreme. In fact they did detect the signal, at a level which later proved to be unbelievably high when compared to the American experience. When I arrived Eric Vogan was already there and we inherited the VHF receiving equipment. The first thing we did was to look at the temporal structure of the signal and discovered to our dismay that there was no continuous signal (like that reported from Stirling) but only the intermittent signals from a great many meteor trails.
Such signals had been detected by the Stirling group but regarded as a nuisance and various methods had been devised for reducing the incidence of meteor signals. In one report discussing this problem, written, I think, by Vic Pineo, there was the intriguing suggestion that if the meteor interference could not be eliminated some method might: be found to utilize the signals for communication purposes. Here we were with nothing but the meteor interference so we naturally turned to looking at its utility for communications purposes. We were not to find out until we had gained experience with our own transmitters and learned much about meteor scattering that the Cedar Rapids-Ottawa path was so atypical that we should not have been trying to draw any general conclusions at all about the utility of meteor scattering. But in our blissful ignorance we went ahead and predicted, on the basis of the meteor signals observed, that a very modest transmitter power would be enough to sustain a teletype link over a distance of 1000 km using burst type transmissions via meteor trails. The "burst" transmission technique is one in which the information is transmitted at very high speed for short intervals and in a meteor system the bursts are arranged to occur only when a suitable meteor trail is present to reflect the signal to the distant receiving station.
Having convinced ourselves that it was possible to communicate reliably with low power at VHF frequencies using meteor-reflected signals, we set about convincing our colleagues. We decided to transmit modulated signals from Ottawa to Port Arthur (now Thunder Bay) and back again by scattering from a single meteor trail- This would establish the feasibility of detecting suitably located trails and using them for two-way communication. Virtually no suitable commercial gear existed so we had to build everything ourselves and here Clare Collins, Del Hansen, Jack Brown and Bill Rolfe contributed a spate of ideas and much hard work. Finally Eric and I traveled to Port Arthur with a mountain of packing boxes. There we negotiated permission to set up our experiment on a pier belonging to one of the grain elevator terminals. There was no shelter on the pier but there was a railway. The antennas were set up on masts which were themselves guyed to the rail line. All the electronic equipment was mounted on a railway push cart which was housed in the grain elevator for safekeeping. Before each experimental session we pushed the cart out to the antennas, connected up and then settled down to listen for the special sequence of modulation tones that would tell us that at least we were receiving signals from Ottawa and re-transmitting the coded signals back.
But we had our troubles. The sight of us trundling our equipment out along the jetty every morning and back again whenever it rained so intrigued the local populace that they frequently came by for a closer look in their inboard or outboard powered boats or even in light aircraft. The ignition systems of all these vehicles produced enormous amounts of electrical noise which completely swamped the faint radio signals we were trying to detect. In those days too, high precision frequency sources were too delicate to be used in portable equipment so we had no way of knowing precisely where in the frequency band the desired signal was to be found, we just had to look for it. Nevertheless, after a few days of searching, the signal was found both at Port Arthur and Ottawa and we all sat back for several hours while meteor after meteor triggered the system into successful operation. The moment of success was even more rewarding because the number of meteors and the total period of actual operation was just slightly in excess of that predicted on the basis of the Cedar Rapids signal. Later, after we had more experience and Colin Hines and Lorne Campbell had worked on the statistical properties of meteors it became evident that in making the predictions we had neglected several very important factors all of which just happened to cancel out.
From then on the JANET project (so named after the Roman god Janus) gathered momentum. We realized that the Port Arthur test would convince our colleagues, which it did, but would hardly "sell" the system to a potential user. So we built an actual communication system.- The only conventional parts of the system consisted of two teletype machines physically separated by about six feet in a lab in Ottawa. If you typed a message on one of them it would appear in due course on the other having in the meantime traveled to Dartmouth, Nova Scotia and back again and been reflected twice off the same meteor trail. Since there were no high-speed printers or even high-speed storage devices this remarkably circuitous method of communicating across the room was accomplished by a series of homemade electromechanical gadgets including a tape recorder that intermittently spewed magnetic tape into a standard-government-issue waste basket from whence it was pulled at a more sedate pace by another tape recorder. This system would have delighted Rube Goldberg and it certainly delighted us. Improbable as it was, it worked and did indeed generate some enthusiasm among potential users in the Services, Looking back on it now, the moment when other people started to take JANET seriously was the moment that we started to enjoy it less. Because the one thing that can be said about the early days of JANET is that they were enormous fun. We worried a lot but we laughed a lot and then suddenly people were taking the whole thing seriously. Everything had to be done by means of specifications, deadlines and performance tests and the joy went out of it all.
There were a few more pleasant moments left in the JANET program, Certainly I'll always be grateful that it brought me in touch with that wonderful group at Stanford University of which Manning, Villard, Peterson and Eshleman were the backbone. At a time when hard-nosed professionalism which came close to cut-throat competition, was becoming the norm in scientific circles it was refreshing indeed to meet a warm-hearted carefree group whose accomplishments were in the front rank but who nevertheless treated each other and their scientific competitors with gentility, thoughtfulness and generosity. Later on, JANET was overtaken by the high-capacity systems, such as microwave and satellite links, and much of what caused us weeks of careful design and months of development time is now commonplace, but I don't regret a minute of it. There's no accounting for tastes and at that time and in that place JANET was our "thing" and it certainly "turned us on".
There were other things going on around the lab. The staff was young and amazingly fertile. Indeed it was widely held that the name of the laboratory had been changed from Radio Propagation Lab to Radio Physics Lab because too many people were taking the propagation part seriously. There was at that time a pleasant little custom. Instead of the usual chocolates or cigars the new father was expected to buy coffee for everyone at the morning coffee break. There were not so many people on the staff that this duty imposed any great financial burden on the lucky fellow but nevertheless free coffee days arrived with startling frequency. One day in 1953, the system broke down completely when it became known that Jean Hay, Doris Montalbetti and my wife Lucille had all, within the space of a few hours presented their husbands with new sons.
Laboratories, like men, mature and change, only in the case of laboratories the process is probably quicker. By 1957 when the laboratory embarked on a substantial participation in the International Geophysical Year the maturation process was well advanced. The laboratory was probably more efficient, more reliable and more expert than it had been earlier but it was also bigger and with bigness came more and stronger organization. There were fewer and fewer outcroppings of that exuberant self-confidence that had characterized the earlier days. Still there were a few happy diversions around the lab. I don't know who started it but we used to bombard each other with bad verse. Probably the leading practitioners of this low art were Ted Hartz and Colin Hines, although Del Hansen, Owen Storey and many others took part. I can only bring myself to quote one of those awful "pomes". It appeared on the bulletin board the day after Jim Scott called a meeting to discuss the lab's participation in the IGY:
Submit a plan, or two if you can
For the Geophysical Year
You're really hot, if it costs a lot
Because "Everything good is dear".
All of the nations, are building new stations
So let us not build too few.
Of single men, we need about ten
Or five single girls might do.
The searchers require, a site even higher,
To look for a soft radiation
Fifteen volunteers, (fourteen of them skiers)
Want work at the new mountain station.
Gauge and record, until you are bored,
The aurora and radio static.
The charts as corrected, must all be collected,
Then hidden in somebody's attic.
So you're very naive, if you try to receive
Some work in this major event.
The more thoughtful man just lays down the plan,
Then directs how the money is spent.
But after all, there is no call
To do anything more than dream
The funds denoted may not get voted
So don't depend on the scheme.
Though the policy's firm for a definite term,
It may need some modification,
Another retirement, or staff requirement
Could cause a reorientation
And the IGY brought what was for me my last truly exciting few weeks in RPL. We had for several months been expecting the launching of the American satellite but its orbit was to be at low latitudes so that we would not be able to make any use of it. Suddenly in October 1957, Sputnik was launched. Not only was it passing regularly over Canada but it carried a radio beacon that was intended to assist in the tracking process. Since the launch was unexpected there were few, if any laboratories outside the USSR set up for the determination of the satellite orbit, but the determination of the orbit at many places in the world was important and the earlier the better because this would give new information about the earth's gravitational field and about its atmosphere.
Because the launch was unexpected all the radio observatories and laboratories in the Western World were starting even in a light-hearted "race" to see who could first determine and describe the satellite orbit.
I remember hearing the first announcement of the satellite and its radio beacons on the CBC News. Within minutes Clare Collins had agreed to meet me at the lab and within hours we had picked up the Sputnik signal and were devising methods to determine the precise location of the satellite each time it approached Ottawa. As they showed up to work on Monday morning, others, including Colin Hines, were recruited. As word spread of our initial progress offers of assistance came in from the National Research Council's Radio and Electrical Engineering Division and from the Department of Transport's monitoring station. All such offers were gratefully accepted, because we were learning as we went. Most of us hadn't thought about orbital motion since undergraduate days but we relearned what was needed in a few days, or at least what we thought was needed. Later, Nature (and the Russians) trapped us neatly. Sputnik 2 was launched into an orbit for which many of the approximations that we had made for Sputnik I proved to be invalid. Fortunately, since we were still doing all our calculations by hand we realized something was wrong. Some of the other groups who were using computers kept churning out quite ridiculous orbital parameters for some time. But for Sputnik I all went smoothly. After three nearly sleepless days and nights of observations and calculations we had narrowed the possible orbits down effectively to two and here the NRC people were able to give us a single observation that eliminated the ambiguity. We had the orbit and happily sent it off by telegram to the World Data Center in Washington. Later it was confirmed that this was the first valid orbital determination made and reported, at least in the Western Hemisphere and probably one of the first, if not the first in the Western World. An accomplishment of no great lasting import because we all learned quickly to use much more sophisticated techniques for tracking satellites. But it did represent one more of those occasions which seemed to come often at RPL when a group of scientists could share the high excitement, the unique comradeship and the rare sense of fulfillment that comes from tackling together a challenging and demanding physical puzzle. I left RPL, partly because I felt both it and I were losing our youth, but more because I felt a real sense of duty toward the institution that had prepared me for the adventurous times at RPL and which I felt should be preparing others for the same purpose. And we were told that the universities were seriously in need of help. That particular "crisis" of the 'universities is long past. There are other crises now and I'm sure there are more to come. The numbers of graduate students may fluctuate wildly but the thoughtful apprenticeship by which a young person turns himself or herself into a scientist goes on. In our hearts we professors know that the best of these will become good scientists with or without our help. That doesn't prevent us from adopting an almost parental attitude towards our students and it has just occurred to me that I would wish nothing better for any graduate student of mine (or for my son) than that he should join some new RPL in its nascent years and there experience the excitement, the fun and the gleeful successes that characterized our RPL in the 50's.