Which measurement indicates how far the search radar in the AN/TPN-24 ASR can reach?

The measurement indicating how far the search radar in the AN/TPN-24 ASR can reach is expressed in nautical miles. The use of nautical miles is common in aviation and maritime contexts because it is based on the Earth's latitude and longitude, making it particularly useful for navigation over large distances.

Nautical miles account for the curvature of the Earth, allowing for more accurate readings when flights or vessels traverse long distances across the ocean or over land. In the context of radar systems like the AN/TPN-24 ASR, which are often used to track aircraft movements over considerable distances, this unit of measurement provides a clearer understanding of range capabilities compared to kilometers, meters, or feet—all of which are less conventional in aeronautical operations.

Using nautical miles helps pilots and air traffic controllers communicate more effectively about distance and positions in relation to the navigational coordinates used in aviation.