Fast Time Constant is typically used for what condition?

• A. Heavy weather
• B. Clear weather
• C. Night operation
• D. Low power conditions

Answer: (C)

Time constant on a radar display controls how long echoes linger on the screen. A fast time constant makes echoes fade quickly, giving a highly responsive, short-persistence picture. This is especially useful for night operation because you need rapid updates to detect and track moving targets in low-light conditions, and you don’t want old echoes to obscure newly acquired contacts. In heavy weather, longer persistence helps you observe evolving storm patterns, so a slower time constant is preferred there. Low power situations aren’t typically tied to needing fast display persistence, and clear weather doesn’t demand the rapid refresh as strongly as night operations.