In recent years an increased tendency for using real-time observation data for a precise point positioning by means of global navigation satellite systems has emerged in the field of position and navigation. Especially the principle of Precise Point Positioning (PPP) has become a well established technique for the determination of the position in real-time. By using undifferenced code and phase observations in combination with precise satellite orbits and clock corrections, positions in the range of a couple of centimeters can be obtained. Additional effects which must be considered are the influence of the ionosphere and troposphere, relativistic effects as well as a number of additional effects of small scale. However, despite of these models and corrections, it is still not possible to fix the ambiguities in PPP. This is why the ambiguities are estimated as float values in the conventional approach, which implicates an increased convergence time as well as a decreased position accuracy. Within the scope of this thesis the conventional PPP error model will be extended by additional fault effects. Fault effects, which have been not taken into account so far, are the so-called UPDs (uncalibrated phase delays), which are the missing link for fixing the ambiguities. In the past years different approaches for the calculation of these UPDs have been developed. In the course of this thesis a software for the calculation of the UPDS from network data was constructed. A primary feature of this software is the possibility to estimate the UPDs in a real-time simulation mode. This mode allows for investigations on the influence of different errors by means of a real-time conformal estimation of the UPDs, which are a main issue of this thesis. It can be proofed that these parameters have significant a influence on the estimation of the UPDs but on the other hand in real-time they are only available with limited accuracy.