While crawling up the 5% grade to the launch location, the crawler uses a ladder guiding system and a leveling device to maintain the mobile launcher platform level with 10 minutes of arc.
当爬行5%坡度到达发射位置时，履带车利用梯子引导系统和调平装置以10分钟弧度保持移动发射器平台水平。
Minutes of arc
原声例句
奇趣工程百科
英语百科
Minute and second of arc
（重定向自Minutes of arc）
![Comparison of angular diameter of the Sun, Moon, planets and the International Space Station. To get a true representation of the sizes, view the image at a distance of 103 times the width of the](/Images/godic/202501/27/Comparison_angular_diameter_solar_system.svg4515.png")
![](/Images/godic/202501/27/SI_base_units.svg4515.png")
A minute of arc, arcminute (arcmin), arc minute, or minute arc is a unit of angular measurement equal to one-sixtieth (1/60) of one degree. As one degree is 1/360 of a circle, one minute of arc is 1/21600 of a circle (or, in radians, π/10800). A second of arc, arcsecond (arcsec), or arc second is 1/60 of an arcminute, 1/3,600 of a degree, 1/1,296,000 of a circle, and π/648,000 (about 1/206,265) of a radian. These units originated in Babylonian astronomy as sexagesimal subdivisions of the degree; they are used in fields that involve very small angles, such as astronomy, optometry, ophthalmology, optics, navigation, land surveying and marksmanship.