prime ĥ vertical卯酉圈
compass prime vertical[航] [水运] 罗盘的东西圈
prime vertical transit卯酉面中星仪
prime vertical lane卯酉面
true prime vertical真东西圈
grid prime vertical[航] [水运] 格网主垂面
magnetic pipe prime vertical磁卯酉圈
magnetic prime vertical磁东西圈;[地物] 磁卯酉圈;磁主垂面
the prime vertical circle正在翻译;主要的垂直圆
N（名词） the great circle passing through the observer's zenith and meeting the horizon due east and west 卯酉圈 [astronomy]