Terrestrial and Celestial Coordinate Systems*

Terrestrial (long,lat)	Celestial equator (, )	Horizion (h,Zn)	Ecliptic (, )	Galactic (l,b)
equator	celestial equator	horizion	ecliptic	galactic equator
poles	celestial poles	zenith, nadir	ecliptic poles	galactic poles
meridians	hours, circles, celestial meridians	vertical circles	circles of latitude
prime meridian	hour circle through ¹, Greenwich celestial meridian, local celestial meridian	principal vertical circle, prime vertical circle	circle of latitude through ¹	great circle through galactic poles so that angle to celestial north pole is 123°
parallels	parallels of declination	parallels of altitude	parallels of latitude
latitude (L, lat)	declination (,d)	altitude (h)	celestial latitude ()	galactic latitude (b)
colatitude	polar distance	zenith distance	celestial colatitude	galactic colatitude
longitude (,long)	sidereal hour angle (SHI) right ascension (RA, ), Greenwich hour angle (GHA), local hour angle (LHA)	azimuth (Zn) azimuth angle	celestial longitude ()	galactic longitude (l)

*This table is from the 1965 edition of the Aerospace Dictionary.
For definitions of terms, see individual entries.

1 =first point of Aries