Initial Ionospheric Ion Line Results and Evaluation by Sanya Incoherent Scatter Radar (SYISR)

Abstract

Abstract A new incoherent scatter radar (ISR) has recently been dedicated at Sanya (SYISR), China (geographic 18.34°N and 109.62°E) to detect the low‐latitude ionospheric plasma by conducting continuous operation and electronic beam steering on a pulse‐to‐pulse basis. This paper provides an overview of the processing procedure of SYISR ion line data and presents some preliminary observational results under various transmitting signal schemes and different working modes, such as the zenith‐directed mode and meridional and zonal scanning modes, with comparison to the international reference ionosphere model (IRI‐2016), ionosonde and Ionospheric Connections Explorer (ICON) satellite measurements. The diurnal and altitude versus latitude variation characteristics of electron density ( N e ), electron temperature ( T e ), and ion temperature ( T i ) are in accordance with those of other ISR measurements in mid‐low latitudes, and IRI shows some discrepancies with SYISR observations, including the sunrise and sunset enhancement in SYISR_ T i and the overestimated IRI_ T e . The comparison between the daytime SYISR_ T i and ICON_ T i shows good consistency based on 31 observational samples. The measurement of line‐of‐sight velocity ( V i ) for long pulse can reveal the properties of the medium scale traveling ionospheric disturbances manifesting the radar's potential to study the mesoscale ionospheric variation in the Sanya area. The derived vector velocities with a better measurement accuracy during the day are generally in line with ionospheric plasma physics. The results show that SYISR can obtain continuous ionospheric parameters through multi‐beam scanning measurements at ∼700 km horizontal scale, which provides important information for studying the atmosphere‐ionosphere‐magnetosphere coupling and ionospheric scintillation at low latitudes in East Asia.