RESPONSIBILITIES OF THE CANDIDATE : The main objective of this 6 month internship will be to analyze the clock stability of a hybrid GPS/Galileo signal simulator. These clock models will be used in the IF and RF level design of the hybrid GNSS signal simulator. The work will start with a thorough study of the various existing clock models for the various GNSS systems on the market and the latest scientific and technical publications related to clock stability. The main parameters will be analyzed and the most important models will be selected. The next step will involve the design and the implementation in simulation and in real time of several clock models which have been chosen in the previous step. Analysis and validation will be performed in simulation and in real time. The design will be based on the development of controlled, highly stable clock models adapted for GNSS signal simulator. The intern student will also support the other members of the research team by means of real-time experiments or whenever his help would be needed. He will also work on real-time signal processing for a better coherence between simulation and real-time tests.