Researchers at the University of Saskatchewan are working on a new way of reading data from high-frequency radars that will allow Canada to more accurately detect aircraft from thousands of kilometres away — and the Department of National Defence has taken note.
This research is being done at the Canadian headquarters of an international network of radars, called SuperDARN (Super Dual Auroral Radar Network). This national research facility, one of 19 currently funded through the CFI’s Major Science Initiatives Fund, monitors space weather, like the aurora borealis, as well as other activity in the upper atmosphere.
Canada's participation is led by the University of Saskatchewan, a founding member and lead scientific partner in the international SuperDARN network, which oversees five radars located in the Northwest Territories, British Columbia, Saskatchewan and Nunavut.
SuperDARN’s radars, also called over-the-horizon radars, emit high-frequency radio waves that refract — or bend — in the upper atmosphere allowing them to travel long distances parallel to the curvature of the Earth. The waves bounce off targets and return to radar receivers. The farther the target, the weaker the signal.
At the moment, these research radars can detect planes, but only at relatively short ranges. However, higher-powered radars like the Canadian military is planning for will easily detect planes at a few thousand kilometres or further — much beyond the couple hundred kilometres of detection that line of sight radars, which operate at higher frequencies than over-the-horizon radars, are capable of, according to Glenn Hussey, the director and principal investigator of SuperDARN Canada.
Tracking defence targets in the High Arctic
In July, Canada committed to a partnership with Australia to bring early warning radar coverage to the Arctic. These over-the-horizon radars from Australia are set to replace the North American Aerospace Defence Command’s (NORAD) North Warning System, which is aging into obsolescence.
Over-the-horizon radar technology is being tested and rolled out around the world, but reading the data reflected back to radars is more complicated in polar regions because the aurora is also reflected, making aircraft signatures harder to identify through that “noise.”
This problem led to a collaborative study with Defence Research and Development Canada and the US Naval Research Laboratory that demonstrated that space weather was interfering with the military’s ability to track targets in the High Arctic.
SuperDARN researchers are now working on algorithms and planning for AI-tools that will help filter radar data and provide easier identification.
“As a rule of thumb, aircraft are going to have a smaller scattering cross-section, but it’s going to be very intense because they’re all metallic, whereas looking at the aurora is going to be spread out over a large area.”
This study highlighted the great importance of taking into consideration radar aurora detection, which can significantly interfere with aircraft detection, in order for over-the-horizon radars to be a viable option for surveillance in the High Arctic.
Hussey says the research team is now in talks with the Department of National Defence to move the research from the proof-of-concept phase to a more operational one.
“We are continuing this research because we feel that this will be really critically important for the security of Canada,” Hussey says.
New CFI-funded technology is a “game changer”
The aircraft-detection project became possible after SuperDARN was able to upgrade its radar data collection abilities with the help of CFI funding.
Before the upgrades, completed with support from the CFI’s Major Science Initiatives Fund, all the signals from each antenna making up the two SuperDARN antenna arrays, would be collapsed into two data streams, Hussey explains.
“Now, we have all 20 antenna data streams raw, and we can combine them however we want after the fact. So, this is a complete game changer that CFI has allowed us to move to an extremely modern, software-defined radio system,” Hussey says.
This advanced technology is providing many new areas of research to explore according to Hussey, including enhancing our understanding of space weather to help mitigate the disturbances solar storms can cause in technology here on Earth.
“The opportunities for us are limitless.”
He says that advanced techniques developed at SuperDARN will continue to have benefits for Canada, including advancing Canadian Arctic sovereignty through surveillance and a physical presence in the High Arctic.
“You never know where fundamental research of natural phenomena, like the aurora, will take you. In our case, using radar to study the aurora is going to have applications for defence and probably more.”
