Analysis of COSMIC-2 Radio Occultation Observations and Atmospheric Profiles

Objectives COSMIC-2 constellation, as the follow-on mission of constellation observing system for meteorology ionosphere and climate(COSMIC), has refined the radio occultation (RO) payloads with multi-GNSS signals support and high-gain beam-forming RO antennas, which will improve both the quantity and quality of the RO observations.

Methods We focus on the input observations and output profiles of the RO retrieval, evaluating the raw observations from both precise orbit determination (POD) and RO antennas, and accessing the atmospheric profiles using ECMWF (European Centre for Medium-Range Weather Forecasts) reanalysis products as reference.

Results The results show that the L1 signal-to-noise ratio (SNR) on COSMIC-2 POD antennas are mostly above 45 dB, and the corresponding pseudo-range multipath standard deviation errors are between 0.2 m and 0.4 m. The SNR values on RO antenna are significantly improved from less than 700 v/v on COSMIC to 1 200 v/v on COSMIC-2, and both the GLONASS and GPS RO profiles show good consistency with ECMWF reanalysis products.

Conclusions The updated COSMIC-2 RO payloads can increase the profile number, and also the quality of RO profiles can be significantly improved with high-gain antennas, which will provide important observations for atmospheric scientific research.