• Single Point (or Point) versus Relative positioning
• Static versus Kinematic positioning
• Real time versus Post mission (post-processing based) positioning

(a) Single Point Positioning

• Code measurements (explained later) are used to compute receiver position directly where coordinates of a receiver at an unknown point are sought with respect to the earth's reference frame by using the known positions of the GPS satellites being tracked (Figure 12.1).
• It is also referred to as absolute positioning , and often just as point positioning.

(b) Relative Positioning

• Coordinates of a receiver at an unknown point are sought with respect to a receiver at a known point using code and/or carrier measurements (Figure 12.2).
• The baseline or baseline vector (dx, dy, dz) is computed from a point of known position to a point of unknown position.
• The term differential positioning is sometimes used interchangeably with relative positioning which is more often associated with a specific type of relative positioning which applies corrections measured at a known site to measurements at an unknown site.