Comparison of COSMIC and COSMIC-2 Radio Occultation Refractivity and Bending Angle Uncertainties in August 2006 and 2021

We compare the random error statistics (uncertainties) of COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate, C1) COSMIC-2 (C2) radio occultation (RO) bending angles refractivities months August 2006 2021 over tropics subtropics using three-cornered hat method. The uncertainty profiles are similar two RO missions in troposphere. However, a higher percentage C2 reach close to surface moisture-rich tropics, an advantage signal-to-noise ratio (SNR) C2. uses signals from both GPS (Global Positioning System) GLONASS Global Navigation Satellites (GNSS). occultations show smaller uncertainties stratosphere lower mesosphere (30–60 km) than occultations, result more accurate clocks. Therefore, (GPS) C1 between 30–60 km while (GLONASS) larger those C1. vary with latitude at all levels. find that horizontal gradients temperature water vapor, therefore refractivity, major cause tropopause region troposphere through violation assumption spherical symmetry retrieval refractivity.