What is Local Mean Time (LMT) based on?

Local Mean Time (LMT) is based on the time observed at a specific meridian of longitude. This means that LMT is calculated based on the position of the sun relative to that particular meridian, reflecting the mean solar time for that location. Each geographic location has its own LMT that corresponds to its longitude.

For example, LMT at a given meridian would align the noon hour with the time when the sun is highest in the sky for that specific longitude. This concept is essential for navigation because it allows sailors and aviators to determine their local time based on their longitudinal position, which aids in calculations like determining time differences and aligning with other time zones.

In contrast, the other options do not accurately represent the basis for LMT. The average time across all meridians is more relevant to standard time zones rather than local mean time, while the local time at the equator does not specifically pertain to LMT as it is tied to a specific longitude. Lastly, the standard time at the North Pole is not applicable, as the North Pole is where all longitudinal lines converge, making the concept of local time less relevant there.