In order to improve the performance of the determination of position, velocity and time by means of GNSS measurements, nowadays Chip Scale Atomic Clocks (CSACs) are frequently used, which provide a highly stable frequency signal to the GNSS receiver. However, until now, the improvement of the navigation solution has only been algorithmic. In this project, the influence of the receiver clock on the quality of signal processing in a software receiver will be investigated by adapting the internal processing steps to the high frequency stability of the CSAC signal. In addition, the feasibility of fingerprinting with highly stable atomic clocks under different dynamic conditions will be investigated and additional integrity measures for GNSS-based time transfer will be developed.