Search results
Results from the WOW.Com Content Network
A geographic coordinate system (GCS) is a spherical or geodetic coordinate system for measuring and communicating positions directly on Earth as latitude and longitude. [1] It is the simplest, oldest and most widely used type of the various spatial reference systems that are in use, and forms the basis for most others.
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Help; Learn to edit; Community portal; Recent changes; Upload file
Geodetic latitude and geocentric latitude have different definitions. Geodetic latitude is defined as the angle between the equatorial plane and the surface normal at a point on the ellipsoid, whereas geocentric latitude is defined as the angle between the equatorial plane and a radial line connecting the centre of the ellipsoid to a point on the surface (see figure).
BeiDou Coordinate System, China Terrestrial Reference Frame (CTRF) 2000 = ITRF97 at epoch 2000.0; own implementation. GLONASS PZ-90.11 is nominally its own system, but is quite close to ITRF and uses many of the same techniques. [2] National systems: United States: WGS 84 (see above); domestic use is mainly based on NAD 83 instead.
WKT can describe coordinate reference systems. For example, the WKT below describes a two-dimensional geographic coordinate reference system with a latitude axis first, then a longitude axis. The coordinate system is related to Earth by the WGS84 geodetic datum:
The equal-area projection that results from average of sinusoidal and Mollweide y-coordinates and thereby constraining the x coordinate. 1929 Craster parabolic =Putniņš P4: Pseudocylindrical Equal-area John Craster Meridians are parabolas. Standard parallels at 36°46′N/S; parallels are unequal in spacing and scale; 2:1 aspect. 1949
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Example: grid with coordinates (φ,λ,z) where z is the elevation. A standard Geoid surface. The z coordinate is zero for all grid, thus can be omitted, (φ,λ). Ancient standards, before 1687 (the Newton's Principia publication), used a "reference sphere"; in nowadays the Geoid is mathematically abstracted as reference ellipsoid.