The Analysis of the Ionospheric Radio Occultation Data Coverage for ANCHOR Ionospheric Data Assimilation

The Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC-1 and COSMIC-2) missions provide global observations of atmospheric and ionospheric conditions using Global Navigation Satellite System (GNSS) radio occultation (RO). While distributing satellites across different orbital inclinations ensures broad spatial coverage, it does not inherently guarantee uniform improvements in electron density estimation across all data assimilation (DA) methods. This study evaluates the impact of various RO constellation configurations on ionospheric space weather nowcasting using ANCHOR, a DA model developed at the Naval Research Laboratory. Observing system simulation experiments (OSSEs) quantify global enhancements in ionospheric state estimation and identify the optimal number of satellites before diminishing returns are observed. These findings are critical for agencies such as National Oceanic and Atmospheric Administration and the Department of Defense, informing the design of future RO missions to improve space weather monitoring and operational forecasting capabilities.