Ken Tapping, April 07, 2010

Last Saturday the local museum in Penticton put on a little Birthday Party for our observatory. There was a chocolate cake bearing the message: "Happy 50th Birthday DRAO". Our observatory has been in the Okanagan for 50 years. The choice of site for DRAO has proved excellent. How was it made?

Canadian radio astronomy got going in the late 1940's, powered by the torrent of technical breakthroughs that took place during the Second World War. Scientists at the National Research Council's laboratories in Ottawa used bits of wartime radar equipment to make this country's first radio telescopes. These instruments were set up just outside Ottawa and were used to make two great discoveries: one desirable and one definitely not. The desirable one was varying radio emissions from the Sun; the undesirable one was the sheer intensity and persistence of manmade radio interference that hit the radio telescopes.

Back in those days there were no computers to record the strength of the cosmic radio signals; they were recorded on moving strips of paper chart by pens loaded with very permanent ink. Violet, black, red and green were popular colours. In addition everybody went to work wearing suits, shirts and ties. A serious problem was that bursts of strong interference moved the pens across the chart so quickly the ink would spray across the room, and across all those nice white shirts and ties. The difficulty of dealing with interference issues at work and persistent ink stains at home led to a decision. If Canadian radio astronomy were to have a future, it would have to be done from a location where the interference level was much lower; a search was made for a suitable site for a new national radio observatory.

In a country with an average population density of about three people per square kilometre, one would think there would be lots of remote locations to fit the bill. However, it's more complicated than that. A science facility requires an on-site staff of technologists, engineers and scientists. These have or would eventually have families, who need homes, schools, shopping and communities to live in. To build the observatory and keep it running requires contractors to do construction and maintenance, and it needs power, water and communications. The preferred site would be low interference and close to communities. A local airport would be a huge plus. The Okanagan proved ideal. The secluded White Lake Basin screened by hills provided the low interference environment, and a short drive reached the communities of the Okanagan Valley. So a pin was stuck in the map, construction started, and in March, 1960, the Dominion Radio Astrophysical Observatory started making discoveries. Thanks to new technical developments, community involvement and ongoing support by Industry Canada, the interference environment continues to be excellent, and the next few years will see new instruments being set up to make scientific use of it.