17:15 〜 19:15
[PEM12-P11] Effects of Wake on Electron Temperature and Density Measurements by Langmuir Probe Onboard Sounding Rockets
To understand the atmospheric and electromagnetic conditions in the upper atmosphere of the Earth, numerous sounding rockets have been launched. The Langmuir probe is an instrument used to measure electron temperature and density and has been installed on many sounding rockets. It is also scheduled to be onboard the sounding rocket S-310-46, which is planned for launch in the summer of 2025, to elucidate the electron temperature structure in the sporadic E layer.
Since sounding rockets fly with a high speed while spinning, their motion affects the measurement data. In particular, when the probe exists in the wake, which is located behind the rocket’s trajectory, significant variations in the observed electron temperature and density occur. To eliminate this effect, a common approach is to exclude data obtained when the probe is inside the wake (Watanabe et al., 1989). Therefore, it is essential to accurately determine the extent of the wake’s influence and to understand the physical processes involved in the estimated electron temperature and density.
In this study, we aim to quantify and model the impact of the wake on electron temperature and density estimation to develop a correction method. We analyzed observation data from the Langmuir probe onboard the S-520-29 sounding rocket, as well as estimated attitude data of the rocket. The S-520-29 rocket was launched from the Uchinoura Space Center at 19:10 in August 2014 and reached a maximum altitude of 243 km. One of the distinguishing features of this rocket is its large precession motion with a short period.
First, using the observational data from the Langmuir Probe, we compared the magnitude of the wake effect with parameters such as rocket velocity, plasma density and attack angle (the angle between the rocket’s axis and velocity vector) to investigate the interrelationship. Based on this analysis, we developed a numerical model to correct for the wake’s influence and examined methods to adjust the measured values inside the wake.
In the future , we plan to further validate the applicability of the developed correction method in preparation for the launch of the S-310-46 rocket, aiming to improve the accuracy of observational data. Specifically, we seek to construct a more versatile correction model that accounts for the wake’s effects at different altitudes and plasma environments. By doing so, we expect to improve the precision of the electron temperature and density structure analysis and deepen our understanding of the plasma environment in the ionosphere.
Since sounding rockets fly with a high speed while spinning, their motion affects the measurement data. In particular, when the probe exists in the wake, which is located behind the rocket’s trajectory, significant variations in the observed electron temperature and density occur. To eliminate this effect, a common approach is to exclude data obtained when the probe is inside the wake (Watanabe et al., 1989). Therefore, it is essential to accurately determine the extent of the wake’s influence and to understand the physical processes involved in the estimated electron temperature and density.
In this study, we aim to quantify and model the impact of the wake on electron temperature and density estimation to develop a correction method. We analyzed observation data from the Langmuir probe onboard the S-520-29 sounding rocket, as well as estimated attitude data of the rocket. The S-520-29 rocket was launched from the Uchinoura Space Center at 19:10 in August 2014 and reached a maximum altitude of 243 km. One of the distinguishing features of this rocket is its large precession motion with a short period.
First, using the observational data from the Langmuir Probe, we compared the magnitude of the wake effect with parameters such as rocket velocity, plasma density and attack angle (the angle between the rocket’s axis and velocity vector) to investigate the interrelationship. Based on this analysis, we developed a numerical model to correct for the wake’s influence and examined methods to adjust the measured values inside the wake.
In the future , we plan to further validate the applicability of the developed correction method in preparation for the launch of the S-310-46 rocket, aiming to improve the accuracy of observational data. Specifically, we seek to construct a more versatile correction model that accounts for the wake’s effects at different altitudes and plasma environments. By doing so, we expect to improve the precision of the electron temperature and density structure analysis and deepen our understanding of the plasma environment in the ionosphere.