The Method Of Ambiguity Kinematic Calculation With The Slope Constraint

Ambiguity is the most important factor in the high accuracy measurement results obtained by GPS.Especially in the GPS single epoch positioning process,whether get accurate ambiguity solution in the final positioning result is particularly important.This thesis focuses on the pseudorange observation equation and the carrier · phase observation equation to introduce the difference equation and the traditional algorithm about ambiguity,and put forward an algorithm about the slope constraint single epoch solution of double difference ambiguity,and finally through the experimental verification and analysis the effect of the algorithm.Firstly,this thesis describes the pretreatment of GPS observation data based on the introduces of RINEX file format. Through the experimental verification,the satellite coordinates using satellite broadcast ephemeris closed to satellite coordinate results provided precise ephemeris. The broadcast ephemeris interpolation calculation satellite coordinates formula of satellite elevation angle is closed to the satellite elevation angle calculated by LGO.Secondly,this thesis based on the principle of GPS real-time kinematic,deducte the relative positioning in the single difference and the double difference and the three difference positioning,the characteristic and the application of a linear combination of the multiple phase observations are included in the wide lane combination observations,the narrow lanes combination observations, ultra wide lane combination observations and so on. Through the experimental verification, the wide lane combination observation value calculating double difference integer ambiguity is better than directly using the observed value solving the double difference integer ambiguity of the effect.For the real-time kinematic solution of integer ambiguity degrees,the condition number is limited,so we can join the slope constraint conditions.Because of the adding of constraint conditions,so the ambiguity fixing efficiency is improved.The experiment has proved that after adding the slope constraint solver floating-point solution is better than no constraint solving the ambiguity float solution,the solution success rate is improved.This thesis uses the least square algorithm and Kalman filter algorithm to get double difference integer ambiguity solution for real-time kinematic.Due to the single epoch solution of integer ambiguity degree,only using phase observation value calculating integer ambiguity will appear insufficient condition,using pseudo range observations,this thesis respectively,the direct use of pseudo range observations and pseudo range positioning results as the observations to establish mathematical model.Through the experiment,it is confirmed that the pseudo range observations combined with phase observation value to get integer ambiguity effect is better than the effect of pseudo offset of the binding phase observation value get the effect of integer ambiguity,the former ambiguity fixed success rate is also higher than the latter. The solutions of Kalman filtering method effect is dependent on its initial value determined, the Kalman filter solution ambiguity effect is not distinct advantages.