## 3 Research Methodology  
The wetPrf profiles from the PlanetiQ mission encompass atmospheric occultation profiles with detailed moisture information, incorporating parameters such as atmospheric pressure, geometric height, temperature, WVP, and retrieved refractivity. Similar to the COSMIC comparison, the observed refractivity profiles are recorded in the wetPrf data obtained from the PlanetiQ mission. COSMIC has been a pioneering force in advancing our understanding of the Earth's atmosphere. Deployed in the mid-2000s, COSMIC consists of a constellation of microsatellites equipped with RO sensors. These sensors utilize signals from GNSS to probe the Earth's atmosphere, providing precise measurements of atmospheric parameters. Over the years, COSMIC has contributed invaluable data for various atmospheric studies, serving as a benchmark for comparing and validating RO data, such as that obtained from the PlanetiQ mission [30]. The Global Forecast System (GFS), developed by the National Centers for Environmental Prediction (NCEP), is a widely utilized NWP model. Renowned for its global coverage and operational forecasting capabilities, the GFS model assimilates observational data to generate forecasts for various atmospheric variables. As a key player in meteorological modeling, the GFS serves as a significant reference point for assessing the accuracy of RO data, providing a basis for comparison with the PlanetiQ mission profiles [31]. The European Centre for Medium-Range Weather Forecasts (ECMWF) operates a state-of-the-art NWP model, recognized for its high-resolution simulations and global forecasting prowess. ECMWF assimilates a diverse range of observational data to produce accurate and timely weather forecasts. In the context of comparing with the PlanetiQ RO data, ECMWF's NWP model offers a robust benchmark, reflecting advancements in atmospheric modeling techniques. The comprehensive and globally influential nature of ECMWF's predictions positions it as a key player in assessing the accuracy and reliability of RO data from the PlanetiQ mission [32]. The ongoing study involves a comprehensive analysis of PlanetQ pressure, temperature, WVP, and refractivity profiles for the online available profiles in 2023. This evaluation relies on dependable mission profiles from the COSMIC, GFS, and ECMWF NWP models. The aim is to assess and compare the accuracy and reliability of PlanetiQ's atmospheric data against these well-established sources, providing valuable insights into the mission's performance in capturing essential atmospheric parameters. The \"wetPr2\" profiles from the PlanetiQ RO mission were gathered and processed for the comparison, offering a vertical resolution of 100 m within the altitude range of 0-60 km. The \"wetPr2\" data format mirrors that of the \"wetPrf\" profiles generated by COSMIC. \"wetPr2\" constitutes an atmospheric occultation profile inclusive of moisture information. Utilizing gridded analysis or short-term forecasting, the separation of pressure, temperature, and moisture contributions to refractivity is achieved. This file undergoes interpolation to 100-m height levels. These profiles provided a substantial dataset, averaging more than 1700 profiles globally per day during the study period. For the comparison process, the background data used in the 1 DVAR analysis was sourced from the GFS and ECMWF analysis, similar to the COSMIC comparison. Atmospheric data comprising PlanetQ's pressure, temperature, WVP, and refractivity profiles is accessible on the COSMIC-UCAR website ([[https://cdaac-www.cosmic-ucar.edu/](https://cdaac-www.cosmic-ucar.edu/)]([https://cdaac-www.cosmic-ucar.edu/](https://cdaac-www.cosmic-ucar.edu/)) accessed on 7 February 2024). These datasets are formatted in wetPrf NetCDF files and encompass the time intervals from Day Of Year (DOY) 2023.095 to DOY 2023.125 and DOY 2023.199 to DOY 2023.365, representing the initial 198 data days of the year 2023. The study period incorporates information from three LEO satellites: GN02, GN03, and GN04.