The Initial Assessment of Ionospheric Radio Occultation Data of MSS-1 Satellite and Its Applications in Scintillation Exploration

The Macau Science Satellites (MSS-1) mission, consisting of twin low earth orbit satellites (Satellite A and B), is the first low-inclination and high-precision geomagnetic surveying satellite project in China. Among the multiple scientific payloads equipped with the scientific satellites, MSS-1 carries a GNSS radio occultation (RO) receiver on Satellite A, and aims to observe the Earth's ionosphere and monitor the space weather especially in the South Atlantic Anomaly (SAA) area. This paper focuses on the ionospheric data of MSS-1 obtained during the first 3 months after its launch, and assesses the RO products as well as initial scintillation measurements. Results show that MSS-1 RO data have very good agreement with contemporary COSMIC-2 and ionosonde observations. The scintillation amplitude indices S4 are comparable with that of COSMIC-2 and well reflect the occurrence rates and distributions of equatorial plasma bubble and sporadic E (Es) in June solstice season. Special attentions are paid to the SAA longitude sector and inspire explorations on the seasonal variations and local-time dependences of ionospheric irregularities.