Advantages of C-band and L-band atmospheric remote sensing

Atmospheric sounding is an important scientific GNSS application: knowledge of the water vapor distribution is fundamental for weather and climate prediction and can be improved by ground GNSS networks and occultation measurements. All present global and regional navigation satellite systems use frequencies in L-band, which is getting more and more crowded. To generate a larger variety of frequency options and to avoid some of the frequency-dependent errors in navigation, S- and C-band offers some interesting opportunities for scientific applications using GNSS. This paper shows the benefit of S- and C-band for retrieval of atmospheric parameters related to both the troposphere and the ionosphere. The concept comprises the development of models and algorithms for C-band data generation and its processing. A clear advantage of L-C-band combinations over traditional L-band-only linear combinations was successfully demonstrated for ground-based methods as well as radio occultation scenarios.