GPS positioning methods are various and users can use different positioning methods according to different purposes. The GPS positioning method can be divided according to different classification criteria as follows:
The observations used for pseudorange positioning are GPS pseudorange observations. The pseudorange observations used can be either C/A pseudoranges or Pcode pseudoranges. Pseudo-distance positioning has the advantages of simple data processing, low requirements on positioning conditions, no problem of integer ambiguity, real-time positioning can be very easy to achieve, its disadvantages are low observation accuracy, C/A pseudo-range observations The accuracy is generally 3 meters, and the accuracy of P-code pseudorange observations is generally around 30 centimeters, resulting in low positioning accuracy. In addition, if the P-code pseudorange observations with high precision are used, AS is also present. problem.
Carrier phase positioning
The observations used for carrier phase positioning are the GPS carrier phase observations, ie L1, L2 or some kind of linear combination of them. The advantage of carrier phase positioning is that the accuracy of observations is high, generally better than 2 millimeters; its disadvantage is that the data processing process is complex and there is a problem of integer ambiguity.
Absolute positioning, also known as single point positioning, is a mode of positioning using a receiver, which determines the absolute coordinates of the receiver antenna. This positioning mode is characterized by a simple operation mode and can be used for stand-alone operation. Absolute positioning is generally used in navigation and precision applications.
Relative positioning, also known as differential positioning, uses more than two receivers to simultaneously observe a group of identical satellites to determine the mutual positional relationship between the receiver antennas.