Equatorial System
One of the coordinate systems used to ascertain the position of planetary bodies.
The Earth's equator represents the base level. Parallel to this are 90 circles of latitude running in northerly and southerly directions (= Northern and Southern latitudes).
360 meridians (= Western and Eastern circles of longitude) run to the North and South poles.
These lines then are superimposed onto the celestial sphere where the Celestial Equator represents the base level while the celestial North and South poles are equivalent to their terrestrial counterparts.
The degree of latitude equates to the declination while the degree of longitude equates to the right ascension.
The system of latitude and longitude on Earth also is an equatorial coordinate system.