How many Independent Secondary Surveillance Radars (ISSRs) are there in Canada?

The number of Independent Secondary Surveillance Radars (ISSRs) in Canada is important for enhancing air traffic control and ensuring safety in the airspace. The correct answer, indicating there are 20 ISSRs, reflects the well-established radar infrastructure that Canada maintains. ISSRs play a crucial role in tracking aircraft by receiving signals from transponders on board. They provide essential information like altitude and identification, which helps air traffic controllers manage air traffic efficiently.

The figure of 20 ISSRs is significant as it ensures coverage across various regions of Canada, allowing for effective monitoring of both domestic and international flights. This number is consistent with the advanced radar network that provides redundancy and reliability, essential for operating within the vast Canadian airspace.

Other figures, such as 10, 30, or 40, do not accurately represent the current technological capabilities and operational needs of Canada's air traffic management system. The actual number reflects a balanced approach to surveillance needs against operational costs and technological advancements.