What is the required separation from the edge of airspace when aircraft are less than 40 miles from the radar antenna and radar separation is being utilized?

When aircraft are operating within 40 miles of the radar antenna and radar separation methods are being utilized, a separation distance of 1.5 miles from the edge of the airspace is mandated. This requirement is essential for maintaining safe operational distances and ensuring that aircraft are adequately separated to avoid collisions and to account for any uncertainties in radar data. The 1.5-mile buffer is part of the defined criteria that enable air traffic controllers to effectively manage traffic in areas where radar coverage is reliable, ensuring that all aircraft maintain safe distances from the boundaries of the airspace.