Meridian Longitude Official

However, modern technology has subtly shifted the grid. Today's standard reference meridian is the IERS Reference Meridian. Maintained by the International Earth Rotation and Reference Systems Service, this digital line sits roughly 102 meters east of the historical green line painted at the Greenwich Observatory. This shift occurred because modern satellite systems account for Earth's center of mass much more accurately than 19th-century telescopic observations could. From aviation routes to smartphone ride-sharing apps, the concept of the meridian continues to guide global movement. To help me tailor this article further, tell me: What is the or platform for this piece?

Meridian longitude is the geographic coordinate system that measures distances east or west of a designated zero-point line known as the Prime Meridian. While latitude lines circle the Earth parallel to the Equator, longitude lines—or meridians—run vertically from the North Pole to the South Pole. Together, these imaginary lines form a grid system that allows humans to pinpoint any exact location on Earth, navigate the oceans, and standardize time across continents. meridian longitude

This relationship creates our system of international time zones: However, modern technology has subtly shifted the grid

有趣的是，格林威治子午线并非固定不变。天文台在过去数百年里迁址了四次。我们今天所见的本初子午线，是 设立的，它穿过了他自己设计的“艾里中星仪”中心。而由于地球自转轴的微小摆动，现代全球卫星导航系统（如GPS）使用的 国际参考子午线（IRM） 与此线约有 102米 的偏移。 This shift occurred because modern satellite systems account

Whether it's a ship at sea or a car's GPS, locating a precise position requires both latitude and longitude [NOAA].

Every has a counterpart on the opposite side of the Earth, exactly 180° away. This is the Antimeridian . While the Prime Meridian divides East from West at 0°, the Antimeridian (180°) serves a very different purpose: it is the rough foundation for the International Date Line (IDL) .

If meridians are the lines, is the measurement. Longitude is the angular distance, expressed in degrees, minutes, and seconds, of a point on the Earth’s surface east or west of the prime meridian [NOAA]. Degrees ( ∘composed with ): Longitude is measured from 0∘0 raised to the composed with power 180∘180 raised to the composed with power East (E) or West (W). The Prime Meridian ( 0∘0 raised to the composed with power