Session
Session II: Advanced Concepts I
Location
Utah State University, Logan, UT
Abstract
Magnetometers are a key component of small satellite attitude determination and control systems(ADCS). They are typically calibrated on the ground during the spacecraft Assembly, Integration, and Testing (AIT) program.
UNSW Canberra Space have observed magnetometer calibration changes during the AIT program, with the most likely cause being spacecraft component magnetisation. Vibration testing has been noted to result in significant changes to magneto-inductive magnetic sensor calibration biases, and to a lesser extent, scale gains.
Ground-based calibration can be time consuming, manpower intensive and susceptible to human error. For larger spacecraft production runs, it is desirable to reduce or eliminate the time required to conduct calibration.
This paper outlines the use of stochastic gradient descent as a way of calibrating magnetometers on-orbit.
The method was tested using the Buccaneer Risk Mitigation Mission satellite developed and operated jointly by Australia’s Defence Science and Technology Group and University of New South Wales Canberra Space. The newly tuned calibration parameters were successfully tested on-orbit. The results are compared with the values generated during ground-based calibration.
The method reduced error by approximately 20% during a six-orbit test period. The updated parameters result in an angular change in the indicated magnetic direction of up to 7.2 deg.
On-Orbit Calibration of Magnetometer Using Stochastic Gradient Descent
Utah State University, Logan, UT
Magnetometers are a key component of small satellite attitude determination and control systems(ADCS). They are typically calibrated on the ground during the spacecraft Assembly, Integration, and Testing (AIT) program.
UNSW Canberra Space have observed magnetometer calibration changes during the AIT program, with the most likely cause being spacecraft component magnetisation. Vibration testing has been noted to result in significant changes to magneto-inductive magnetic sensor calibration biases, and to a lesser extent, scale gains.
Ground-based calibration can be time consuming, manpower intensive and susceptible to human error. For larger spacecraft production runs, it is desirable to reduce or eliminate the time required to conduct calibration.
This paper outlines the use of stochastic gradient descent as a way of calibrating magnetometers on-orbit.
The method was tested using the Buccaneer Risk Mitigation Mission satellite developed and operated jointly by Australia’s Defence Science and Technology Group and University of New South Wales Canberra Space. The newly tuned calibration parameters were successfully tested on-orbit. The results are compared with the values generated during ground-based calibration.
The method reduced error by approximately 20% during a six-orbit test period. The updated parameters result in an angular change in the indicated magnetic direction of up to 7.2 deg.
