Research On Kinematic GPS Precise Point Positioning Methods

The GPS kinematic Prcise Point Positioning (KPPP) could afford high-precisioncoordinates, with the excellence that break the baseline’s distance limitation, which is the maindifficulty in double-difference positioning method. The application field of KPPP is developingrapidly. The thesis has researched the theory and method of KPPP. The mathmetical method andstochastic models is stated.The error correction model and its influence on positioning precisionis researched amply. While the cycles slips exists frequently around the observed GPS data, thethesis brings forward a new mehod to restore the short-time cycles slips, which is called theimproved least square searching thoery. By studying the algorithm of KPPP, the author hasdevloped the software of KPPP. The validity of software has been proved by anlysing thecomparing result of business-oriented software.The main conclusions of this paper are asfollows:1. In theory, the error propagation formula, which shows the the error’s influence onpositioning, has been derived. Each error source’s influence has being analysised by experimentdata. The influence of Sagnac effect error on positioning is20-30cm, DCB and other error’sinfluence are all above centimetre level. So DCB error should be modeling in the Kinematic GPSPrecise Point Positioning technique. And all error should be mitigated with precise models.2. The mehod’s effect of detecting the cycle slips by using synthetically the geometry-freecombination, the combination of pseudo-range and phase and the TurboEdit method, in thekinematic GPS Prcise Point Positioning, has been analysed. And a new mehod of the improvedLeast Square Searching method is proposed to restore the short-time cycle slips, which restoresthe short-time cycle slips successfully in experiment.3. The software of KPPP has being developed independently, and the empirical value ofeach filter parameters has been shown. Using the Rauch-Tung-Striebel formula in smooth andevaluate theory, the two-way filter algorithm has been improved in theory.4. The validity of algorithm and progress is proved by solving three different types data,which are observed in aviation, vehicle and voyage conditions respectively, and comparing thesolution with the double-difference solution of the business-oriented software’s GrafNav. Thesoftware has reached cm-dm positioning level.5. The two-way filter algorithm, which could enhace the initializal coordinates’ precision,can reduce the time of initialization efficiently.And the fall of the cut-off elevation angle, and theincrease of sample rate can also reduce the time of initialization slightly.