A geodetic reference system
Halves of great circles that all come together at the poles
the angle between the plane of the prime meridian and that of the meridian through a point (E/W direction)
imaginary lines parallel to the equator, perpendicular to the Earth's rotation axis
The angle between the plane of the equator and a line from the point to the center
0-90 N and 0-90 S
Longitude
Degrees, minutes, seconds
Use the rotational ellipsoid model
the ellips (2d) rotates around one of its axes
Oblate spheriod
ellipsoid + where to place the ellipsoid in relation to earth
the centre of the ellipsoid is the centre of earth's mass and this is suited everywhere
Surface of ellipsoid is the geoid for a certain location and very suitable in some locations
equipotential surface in the Earth gravity field. Mean sea surface and its imaginary extension
geoid - ellipsoid
height above sea level/geoid
height above the ellipsoid
ellipsoid model, location of ellipsoid, coordinate system
azimuthal, cylindric, conic
plane touches the earth at one point. Good for small areas
it touches the equator
it touches a meridian
cone touches the globe along a parallel
Equal area, conformal, equidistant
Preserves the relative size of geographic features and distorts the shape of features
Preserves the local shapes and only changes the relative size
Transverse cylindrical projection
Where the projection is correct - defines where the cylinder touches the earth model and the origin of the plain coordinate system
Cone projections