An Evaluation of Beam Configuration to Detect the Plasma Vector Velocity: A Simulation Method Based on the SYISR System

Measuring the plasma motion vector field accurately is beneficial to understanding the physical processes in the ionosphere. As a newly built advanced modular phase array Incoherent Scatter Radar in Sanya (SYISR), SYISR can measure the line-of-sight (LOS) velocity of ion drift in multiple directions, potentially yielding the spatial distribution of ionospheric plasma drift at low latitudes in East Asia. Compared to the traditional ISR, it can operate continuously for a long-time and perform with fast and flexible scanning. This paper evaluates different beam configurations and inversion methods for vector ion velocity detection by comparing the vector ion velocities input in the forward modeling and derived by inversion. For the mono-static SYISR, the all-sky scan mode is suitable for observing the distribution of vector ion velocity with height, and the fine scan mode is suitable for observing the spatial distribution of two components of vector ion drift perpendicular to the magnetic field in the northern region of SYISR's non-grating lobe. For the future tri-static SYISR, it could simultaneously observe the spatial distribution of all three components of the vector ion velocity. Besides, the inversion method based on Bayesian estimation shows good accuracy and stability in deriving the vector ion velocity, especially when the LOS ion velocity has a large error. These results will benefit the design and optimization of the actual experiments for the vector ion velocity measurement and inversion using the SYISR system.