Final answer:
In Mosaic/Multi-Sensor Mode, aircraft operating at or above FL600 must be separated by 100 miles to ensure safety.
Step-by-step explanation:
When using Mosaic/Multi-Sensor Mode, separate aircraft operating at or above FL600 by 100 miles. This standard provides a safety buffer by accounting for the vast distances at which high-altitude aircraft, such as reconnaissance or research aircraft, operate. The use of Mosaic/Multi-Sensor Mode, which aggregates data from multiple sensors to provide a more accurate positional awareness to air traffic controllers, ensures that these aircraft maintain a safe separation distance in these sparse traffic environments.