Wake Potential and Wake Effects on the Ionospheric Plasma Density Measurements With Sounding Rockets

Abstract

A new method is developed to systematically study variations in the electrostatic potential around a spinning spacecraft in flowing plasma. We argue that the main modulation of this potential is due to wake leading to different depletions in electron and ion densities. This wake potential can be calculated with the help of electric currents measured by Langmuir probes mounted on a boom system and the assumption of Boltzmann‐distributed electrons. The wake position is determined with the electric field measurements. We apply this method to data from the Investigation of Cusp Irregularities 3 ionospheric sounding rocket and find the observed wake to be larger than expected from the flow velocity and the Mach cone formation, which can be explained by the presence of booms. By using the wake potential to filter the rocket data, we show that this method is robust during highly dynamic plasma conditions and that it can be used to improve the quality of plasma density measurements and reduce the wake effects.