Development and Validation of Comprehensive Closed Formulas for Atmospheric Delay and Altimetry Correction in Ground-Based GNSS-R

Radio wave propagation involved in Global Navigation Satellite System Reflectometry (GNSS-R) is subject to atmospheric refraction. Even for ground-based tracking stations, applications such as coastal sea-level altimetry, the interferometric or reflection-minus-direct effect might be significant. Although delays are best investigated numerically via raytracing, including reflections, a procedure not trivial. We have developed simpler closed formulas account refraction GNSS-R, validated against independent raytracing. provide specific expressions two components of delay and corresponding altimetry correction components, parameterized terms refractivity bending angle. Assessment results showed excellent agreement both components. define slant factor used map zenithal individual satellites.