GPS Ambiguity Resolution Methods

In Global Positioning System (GPS), ambiguity refers to the uncertainty in the distance measurement between the receiver and satellite, primarily caused by multipath interference along the signal transmission path and clock inaccuracies. One common resolution approach involves implementing Differential GPS (DGPS), which reduces ambiguity by comparing signals between two receivers through techniques like double-difference processing. This method typically utilizes code-based algorithms that calculate differences between satellite measurements to eliminate common errors. Additionally, several advanced ambiguity resolution methods exist, including baseline resolution that employs Least-Squares Ambiguity Decorrelation Adjustment (LAMBDA) algorithms for integer ambiguity fixing, and Network Real-Time Kinematic (RTK) solutions that integrate signals from multiple receivers using Kalman filtering techniques. These methods collectively enhance positioning accuracy by resolving carrier phase ambiguities through statistical validation tests like ratio-testing and integer bootstrapping, often implemented in C++ or MATLAB with specialized navigation libraries.