| 释义 |
本初子午线běnchū-zǐwǔxiàn0°经线,是计算东西经度的起点。1884年国际会议决定用通过英国格林尼治(Greenwich)天文台子午仪中心的经线为本初子午线。1957年后,格林尼治天文台迁移台址。1968年国际上以国际协议原点(CIO)作为地极原点,经度起点实际上不变。{first meridian; prime meridian; meridian of 0°longitude, from which longitude east and west is reckoned. In 1884 it was decided at an international conference to use the meridian line passing through the Meridian Instrument Centre at the Royal Observatory in Greenwich, England, as the first (or prime) meridian. In 1957 the Greenwich Observatory moved to another site. In 1968 the CIO (Conventional International Origin) was internationally adopted the terrestrial pole origin, which actually made no change in the starting point of the meridians.} |