Introduction to GPS and mapping. Global Positioning System. What is GPS ?. Department of Defense developed for navigation Standard positioning service (public uses) Precise positioning service Launches began in 1970s Full operational capability in mid 1990s
Geometric Dilution of Precision (GDOP) – the higher the value, the poorer the measurement (very good = <4, bad = >6)
Datum used effects positional errors
During 1930s, each US state adopt its own projection and coordinate system, generally known as State Plane Coordinates (SPC).
Each state chose its own projection based on its shape to minimize distortion over the area of the state.
Some states have more than one internal zone.
The North American Datum 1983 (NAD83) is commonly used for SPC.State Plane Coordinates