To eliminate ISLS, the P2 signal on the ground radar is transmitted in which radiating pattern?

To eliminate ISLS, the P2 signal on the ground radar is transmitted in which radiating pattern?

• A. Uniform beam
• B. Omnidirectional
• C. Narrow beam
• D. Sectorial pattern

Answer: (B)

To eliminate ISLS, the P2 signal should be transmitted in an omnidirectional radiating pattern. When energy is radiated uniformly in all directions, every aircraft around the radar receives the P2 reference with consistent coverage, regardless of its bearing. This uniform azimuth coverage prevents directional bias that could leave some approaches under-illuminated or create conditions that mimic ISLS signals. A narrow beam concentrates power into a small sector, leaving large portions of the azimuth without adequate P2 energy and risking missed indications or false cues. A sectorial pattern does the same by limiting coverage to a defined arc, which again leaves other directions unlit. Omnidirectional transmission ensures universal reach and consistent detection, which is essential for reliably eliminating ISLS.

To eliminate ISLS, the P2 signal should be transmitted in an omnidirectional radiating pattern. When energy is radiated uniformly in all directions, every aircraft around the radar receives the P2 reference with consistent coverage, regardless of its bearing. This uniform azimuth coverage prevents directional bias that could leave some approaches under-illuminated or create conditions that mimic ISLS signals. A narrow beam concentrates power into a small sector, leaving large portions of the azimuth without adequate P2 energy and risking missed indications or false cues. A sectorial pattern does the same by limiting coverage to a defined arc, which again leaves other directions unlit. Omnidirectional transmission ensures universal reach and consistent detection, which is essential for reliably eliminating ISLS.