небесний меридіан
prime meridian (PM)
north reference direction of geographical meridian
transverse meridian
grid meridian
local meridian
meridian
prime meridian
celestial body
celestial and satellite navigation systems
celestial coordinate system
celestial equator
celestial horizon
celestial monitoring
celestial navigation system
celestial sphere
celestial time
celestial navigation
atmosphere-bearing celestial body
celestial forces
celestial guidance
celestial navigation instrument
celestial position finding
celestial reference
celestial-inertial guidance