Feasibility of wide-area subdecimeter navigation with GALILEO and Modernized GPS

Precise corrections with a three-dimensional voxel model of the ionosphere based on Global Navigation Satellite System (GNSS) data from a wide-area network of ground receivers can help resolve differential carrier-phase ambiguities over very long baselines of hundreds of kilometers in present two-frequency systems [Global Positioning System (GPS) and Global Orbiting Navigation Satellite System (GLONASS)] or in planned three-frequency systems (GALILEO, Modernized GPS). A study based on simulated three-frequency data from a modified GNSS signal generator indicates that all the phase ambiguities could be resolved successfully more than 90% of the time. This should be useful in surveying large areas with instruments that require very precise geolocation (e.g. radar or lidar altimetry, interferometric synthetic aperture radar, interferometric sonar, etc.).