Definition
A pair of angular measurements used to specify any point on the Earth's surface. Latitude measures the angle north or south of the equator (0° to 90°), and longitude measures the angle east or west of the Prime Meridian, which runs through Greenwich, England (0° to 180°). Together, they form a global grid that defines a unique position, typically expressed in degrees, minutes, and seconds (e.g., 34°03'08"N, 118°14'37"W).
Plain English
A two-number address for any spot on Earth. The first number tells you how far north or south of the equator you are, and the second tells you how far east or west of a line that runs through Greenwich, England. Put the two together and you have an exact location.
Context Anchor
Seen on aeronautical charts, in route descriptions, and in published locations for airports, navigation points, and federal airways.
Derivation
Latitude comes from the Latin latitudo, meaning 'breadth' or 'width' — the side-to-side spread of the Earth from equator to pole. Longitude comes from the Latin longitudo, meaning 'length' — the long way around the Earth from east to west. The names reflect how early mapmakers thought of the world: wide across, long around.
Why Pilots Care
Pilots rely on these coordinates to identify exact locations for airways, waypoints, and reporting points during instrument navigation.
Analogy
Latitude and longitude work like a street address for the Earth. Instead of a house number and street name, they use two measured positions to locate one exact spot.
Intuition Check
Latitude/longitude coordinates do not tell you a heading to fly by themselves. They identify a location; you still need navigation information to fly to or from that location.
Example Sentence 1
The pilot entered the latitude/longitude coordinates of the off-airway waypoint into the GPS before departure.
Example Sentence 2
Federal airways are charted using specific latitude/longitude coordinates to mark their centerlines.