Canada's Department of National Defence is looking into buying large swaths of land in southern Ontario to house a new Norad surveillance system.

"This new system will include Arctic and Polar Over the Horizon Radar to provide long-range, early warning radar and threat tracking for northern approaches," a National Defence spokesperson told CTVNews.ca. "Up to four areas will be required for the system’s transmitters and receivers."

Local newspapers ads and an invite interested parties to provide information about available land by Aug. 31. Parcels must be a combined size of one to 12-square-kilometres and located south of the Trans-Canada Highway, which cuts a line across Ontario from roughly Ottawa to Sudbury. 

The notice and ads were posted by Public Services and Procurement Canada and do not specifically mention the Department of National Defence, Norad or the intended purpose of the land.

"Note that this is not a tender process, nor a request for proposal, but only an inquiry as to the land availability of sites," the notice states.

The National Defence spokesperson said existing military properties are also being assessed.

"As part of Canada’s work with the United States to modernize the North American Aerospace Defense Command, the Department of National Defence is creating a new surveillance system to significantly expand Norad and the Canadian Armed Forces’ awareness of objects well before they enter Canadian airspace," the spokesperson explained. "As such, the department is reaching out to private landowners, Indigenous communities, other federal government departments, the Province of Ontario and local municipalities to determine their interest in selling land to (the Department of National Defence) for this project."

Short for North American Aerospace Defense Command, Norad is a joint Canada-U.S. defence group that is responsible for protecting the continent from incoming attacks. Formed in 1958 at the height of the Cold War, Norad and its aging systems are unable effectively defend against emerging threats like Russian and Chinese hypersonic weapons. Canada's most significant contribution to Norad has so far been a string of remote radar stations known as the , which was built between 1986 and 1992.

After years of calls for investment and upgrades, in June 2022 Canada's Department of National Defence's announced a to modernize Norad, which would cover any land acquired for new facilities.

"This is the most significant upgrade to Norad, from a Canadian perspective, in almost four decades," Defence Minister Anita Anand said at the time.

A final decision on the location of the new Norad equipment is expected by spring 2024. The notice says properties may be inspected and must meet operational, security and public safety requirements. More details are available on , the federal government's procurement website.

"The department will also continue to update local communities and government partners as there is more information on the locations of the radar sites," the National Defence spokesperson added. "The Department of National Defence expects this project will create local economic development opportunities and is looking forward to working in collaboration with partners on this NORAD modernization initiative."