Dual Frequency Single Epoch Integer Ambiguity Rounding Resolution Algorithm for Ultra-Short Baseline

Carrier phase differential GPS has been widely used in ultra-short baseline situation such as orientation, attitude determination and deformation monitoring. Carrier phase integer ambiguity resolution is the key issue. It is efficient to round wide lane integer ambiguity by pseudo-range. However, the rounding error for one cycle wide lane integer ambiguity always happens, and when pseudo-range error is large, it may be more than one cycle error. In this work, an integer ambiguity resolution algorithm was designed to offset the wide lane integer ambiguity rounding error. One cycle wide lane integer ambiguity error was detected and fixed by the fractional part of L₁ float solution separated from wide lane. The wide lane integer ambiguity error beyond one cycle was excluded by RAIM algorithm. The whole integer ambiguity was solved by the baseline vector which was calculated by partial right integer ambiguity. Some field tests were carried out based on GPS ultra-short baseline. Results show that, the designed algorithm increases the success rate of directly rounding wide lane integer ambiguity. The success rate is slightly lower but the computational efficiency is much higher compared to single epoch LAMBDA algorithm.