SDR implementations on global navigation satellite systems’ applications have opened an area which provides flexible and adaptable architectures to satisfy the user’s needs in terms of accuracy, robustness, cost etc. SDR architectures have expanding area of usage at both commercial products and military solutions. This paper endeavors for improving the positioning accuracy only by implementing algorithms. In this paper, single L1 frequency GPS and GLONASS SDR algorithms with configurable and different tracking algorithms have been implemented. Signal acquisition, tracking, navigation demodulation and integrity monitoring techniques have been performed in post processing. Through these processes, iFEN SX-NSR Scientific Software Navigation Receiver have been used in order to obtain IF data from a Spirent GNSS simulator or real signals via an antenna. Performance of the code based positioning algorithms has been compared with the PPK (Post Processed Kinematic) solutions created by implemented LAMBDA ambiguity fixing method for only GPS L1 single frequency. Implemented code base positioning algorithms and ambiguity resolution algorithm to eliminate carrier phase ambiguity have been verified with static field tests. As a measure of accuracy, the horizontal distance has been taken into account due to construction of field test setup. NIORAIM algorithms are applied to GPS/GLONASS constellations as an additional option so that non-uniform weights to the visible satellites’ pseudorange values are assigned as being different from RAIM.

Keywords: GNSS SDR receiver, GPS/GLONASS combined solution, LAMBDA method, NIORAIM