The objectives of this activity are the study, design and simulation of techniques for robust carrier phase tracking under high dynamic/strong fading/scintillation conditions.

Carrier phase measurements are more precise than pseudorange measurements and are used for high precision services. The quality of the carrier phase measurements influences directly the Galileo/EGNOS Ground-Segment navigation and integrity algorithms output quality, as well as the GPS/Galileo professional and mass market user positioning accuracy. Unfortunately, phase tracking can be severely stressed under ionospheric scintillation (under severe scintillation, phase may change too fast for being tracked by the receiver). Moreover, cycle slips can occur when tracking is interrupted due to blockage of the signals, or when signal fading is too intense. New and promising techniques enhancing carrier-phase tracking robustness can be envisaged, amongst them:1. Those based on the processing of multiple signals and frequencies (>2).1.1.The correlation of the physical phenomena at different frequencies is known. 1.2. The dynamics of the scintillation imply specific spectral characteristics of the loop the tracking signals2- Those based on open loop estimations (algorithms which require the calculation of a branch metric which embeds an implicit estimate of the unknown parameters based on a "sliding window" of observations) The proposed activity aims at identifying promising techniques that can allow robust carrier phase tracking under high dynamic/strong fading/scintillation conditions. This study includes the study, design, simulation and validation of these techniques