For quasi-real-time method, the real-values of COG and SOG are calculated by Mid-Latitude, Mercator or Bowring sailing method, the geographic coordinates obtained from DGPS are taken as the original datum of the three sailing methods.

• 在准实时法中,利用差分卫星定位仪给出的地理坐标,根据中分纬度法、墨卡托法或波林法算得航迹向与对地速度的真值。