How can birds near a radar site affect system performance and what mitigations are used?

• A. Birds improve signal strength; mitigated by increasing gain.
• B. Birds return strong echoes and clutter the display; mitigated with deterrents and filtering.
• C. Birds have no effect; mitigated by no action.
• D. Birds reduce clutter; mitigated by removing filters.

Answer: (B)

Birds near a radar site can reflect a lot of energy and move through the beam, creating clutter on the radar display. Large flocks or rapid bird motion can produce strong returns that appear like targets, potentially causing false tracks or masking real aircraft. This reduces the radar’s ability to detect and track actual targets, especially in busy airspace or near the field where clutter is high.

Mitigations come from two broad approaches. Deterrents aim to keep birds away from the radar area through habitat management, visual or acoustic deterrents, pyrotechnics, netting, or other bird-hazard measures. By reducing bird presence, you lower the amount of clutter and false echoes reaching the system.

Filtering and processing are designed to suppress or discriminate bird echoes without removing real targets. Doppler and moving-target-indication filtering help distinguish slow, erratic bird motion from aircraft-like motion; adaptive clutter maps and advanced tracking algorithms separate persistent clutter from true targets. Together, deterrents and filtering preserve radar performance by reducing bird clutter and improving the reliability of aircraft detection.