How is a knot defined in aviation terms?

In aviation terms, a knot is defined as one nautical mile per hour. This measurement is crucial for navigators and pilots since it is based on the Earth's circumference, making it particularly relevant for air and sea navigation over long distances. A nautical mile is equivalent to approximately 1.15 statutory miles, and using knots allows for a standardized understanding of speed that correlates directly with the latitude and longitude of navigational charts. This uniformity simplifies the process of travel over the curvature of the Earth, which is essential in both aviation and maritime contexts.

The other options represent different units of speed, such as miles per hour, kilometers per hour, and feet per second, but they do not capture the unique relationship of speed to nautical miles that is integral to effective navigation in aviation.