List all sectors active during ABT Search Mode 1

• A. Horizon, mid-range, long-range
• B. Horizon, short range pop-up, lower medium range, upper medium range, long range.
• C. Short range only
• D. Horizon and long range only

Answer: (B)

ABT Search Mode 1 is about covering all the essential threat envelopes with multiple radar sectors so threats can be detected early across different ranges and altitudes. In this mode five sectors are activated: horizon, short-range pop-up, lower medium range, upper medium range, and long range. The horizon sector focuses on distant, high-altitude targets and gives early warning as they approach. The short-range pop-up sector is tuned for threats that rise quickly from near terrain at low altitude, catching them before they can pose a problem. The lower and upper medium range sectors split the mid-range band into lower and higher altitude slices, ensuring mid-range threats are tracked appropriately across different elevations. The long-range sector maintains coverage for distant targets, including those at high altitude, so far-off intruders can be detected in time. Because this mode combines all five sectors, it provides the complete set of coverage described, whereas other options omit one or more sectors, making them less comprehensive for ABT Search Mode 1.