Study on Differential GPS Positioning Methods

The positioning accuracy of the traditional GPS single point positioning is lower and applies only to the occasion of the low accuracy of the positioning. With the development of GPS positioning technology, the requirements for the positioning accuracy are also constantly improving, using differential GPS technology can improve the positioning accuracy significantly. We can learn from differential GPS that, in order to implement amendments to the user positioning results, base station sends differential corrections to the user station, which can improve the positioning accuracy. Forming differential correction is the key technical problems in differential GPS system. This paper introduces three different differential GPS methods: differential position, differential pseudo range and differential carrier phase, explains the fundamentals and introduces the specific algorithm for differential corrections. We draw the following conclusions by comparing these three different methods: Differential position is simple but the accuracy is lower, differential pseudo range is less limited and the accuracy is moderate, so it is the most widely used differential positioning method, differential carrier phase has the highest accuracy but is more limited.