What does range resolution in radar refer to?

Range resolution in radar specifically refers to the capability of a radar system to distinguish between two closely spaced objects that are at the same distance from the radar source. This is fundamentally determined by the radar's pulse length and the frequency of the signal it transmits. A shorter pulse width allows the radar to create sharper distinctions between objects, effectively improving its ability to resolve features that are very close together in range.

An essential aspect of range resolution is that it directly relates to the radar’s ability to display multiple targets simultaneously without them being conflated into a single echo on the radar display. This is crucial for applications where identifying multiple targets is necessary, such as in air traffic control or marine navigation.

The other choices do not accurately reflect the meaning of range resolution. The maximum distance a radar can detect relates more to detection range than resolution. The width of the radar beam is about the angular coverage of the radar, which contributes to the radar's ability to scan but does not pertain to distinguishing separate targets at the same distance. The time taken for a signal to return pertains more to the calculation of distance rather than the resolution capability to identify closely spaced objects. Thus, the focus on the ability to identify two separate objects close together distinctly highlights the concept of range resolution