A.N. Podkorytov - Ph.D. (Eng.), Senior Lecturer, Moscow Aviation Institute (National Research University). E-mail: thepompous@gmail.com
A.A. Povalyaev - Dr.Sc. (Eng.), Professor, Moscow Aviation Institute (National Research University). E-mail: thepompous@gmail.com

Main disadvantage of Float precise point positioning (Float PPP) methods in global navigation satellite systems (GNSS) is long convergence period. In Float PPP ambiguities of phase measurements are estimated as float values absorbing unmodelled equipment biases without taking into account their integer nature. The use of ambiguity resolution in PPP (Integer PPP) allows to significantly reduce convergence period. Implementation of this procedure requires applying of decoupled clocks for satellites and user receiver which depend on type of measurements, so it leads to singular system of equations. Underlying feature of design matrix in singular systems of GNSS linearized equations allowing to estimate user coordinates with ambiguity resolution of phase measurements is revealed in the article. Algebraic details of overcoming of rank deficiency connected with ambiguity resolution in PPP are considered. Significant reducing of convergence period for PPP due to ambiguity resolution of phase measurements is shown. Comparison of user positioning quality with use of decoupled satellite clocks from global and local networks is presented.

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