Calibrating Electrostatic Deflection of Charged Particle Sensors Using Ambient Plasma Measurements.

Area of Science:

• Space Physics
• Plasma Physics
• Instrument Calibration

Background:

• Advancements in space-based charged particle detectors necessitate improved spatial and temporal resolution.
• Accurate knowledge of measurement errors, particularly sensor pointing error, is crucial for data interpretation.
• Existing methods may lack the precision required for next-generation space plasma instruments.

Purpose of the Study:

• To develop and demonstrate a novel method for estimating sensor pointing error using correlated multi-sensor data.
• To improve the accuracy of sensor pointing beyond native instrument resolution.
• To provide a means for monitoring sensor performance over time.

Main Methods:

• Correlating data from multiple sensors with sharp, naturally occurring signal features in the spacecraft spin direction.
• Utilizing an automated filter on routine science data to identify suitable features for analysis.
• Estimating relative pointing error between sensors with sub-degree precision.

Main Results:

• The developed method achieves sub-degree precision in estimating relative sensor pointing error, approximately 20 times better than native azimuthal resolution.
• Demonstrated effectiveness using flight data from the Dual Ion Spectrometer on NASA's Magnetospheric Multiscale (MMS) mission.
• Identified sufficient natural signal features for robust calibration and post-correction of measured data.

Conclusions:

• The proposed correlation method provides a highly precise and automated approach to calibrate and correct sensor pointing errors in space-based particle detectors.
• This technique enables continuous monitoring of instrument pointing stability, crucial for long-term missions.
• Improved pointing accuracy ensures the scientific integrity of charged particle measurements, especially for missions like MMS.