Date: 2 June, 2023

Dataset Title: Data Set for Underdetermined Blind Source Separation of Cubesat Quad-Mag Magnetometer data

Dataset Creators: A. P. Hoffmann

Dataset Contact: Alex Hoffmann, aphoff@umich.edu

Funding: NASA 80NSSC19K0608, 80NSSC18K1240


Key Points:
- The data set contains data for two experiments
- Quad-Mag Experiment: quadmag_data.txt contains mixed signals data from four magnetometers, copper_room_signals_info.txt contains information about the source signals. 
- Simulation: simulation_source_signals.csv contains timeseries of source signals used to generate virtual quadmag data, simulation_mixing_matrices.txt contains the mixing matrix used to combine the source signals,


Dataset Files
1. quadmag_data.txt. This file includes measurements of four copper coils by four magnetometers.
2. copper_room_signals_info.txt. This file contains information about the source signals in quadmag_data.txt
3. simulation_sourcesignals.csv. This file contains 5 source signals sampled at 50 hz. These source signals are both real and artificial.
4. simulation_mixing_matrices.txt. This file contains the mixing matrices used for 1U-6U simulations in the paper: Enabling Boomless CubeSat Magnetic Field Measurements with the Quad-Mag Magnetometer and an Improved Underdetermined Blind Source Separation Algorithm

Research Overview:
In situ magnetic field measurements are often difficult to obtain due to the presence of stray magnetic fields generated by spacecraft electrical subsystems. The conventional solution is to implement strict magnetic cleanliness requirements and place magnetometers on a deployable boom. However, this method is not always feasible on low-cost platforms due to factors such as increased design complexity, increased cost, and volume limitations. To overcome this problem, we propose using the Quad-Mag CubeSat magnetometer with an improved Underdetermined Blind Source Separation (UBSS) noise removal algorithm. The Quad-Mag consists of four magnetometer sensors in a single CubeSat form-factor card that allows distributed measurements of stray magnetic fields. The UBSS algorithm can remove stray magnetic fields without prior knowledge of the magnitude, orientation, or number of noise sources. UBSS is a two-stage algorithm that identifies signals through cluster analysis and separates them through compressive sensing. We use UBSS with single source point (SSP) detection to improve the identification of noise signals and iteratively-weighted compressed sensing to separate noise signals from the ambient magnetic field. Using a mock CubeSat, we demonstrate in the lab that UBSS reduces four noise signals producing more than 100 nT of noise at each magnetometer to below the expected instrument resolution (near 5 nT). Additionally, we show that the integrated Quad-Mag and improved UBSS system works well for 1U, 2U, 3U, and 6U CubeSats in simulation. Our results show that the Quad-Mag and UBSS noise cancellation package enables high-fidelity magnetic field measurements from a CubeSat without a boom.


Related publication(s):
Hoffmann, A.P., et al. (2023). Enabling Boomless CubeSat Magnetic Field Measurements with the Quad-Mag Magnetometer and an Improved Underdetermined Blind Source Separation Algorithm. https://doi.org/10.1029/2023JA031662.


Use and Access: 
This data set is made available under a Creative Commons Public Domain license (CC0 1.0).


To Cite Data: 
Citation TBA. Search "for Enabling Boomless CubeSat Magnetic Field Measurements with the Quad-Mag Magnetometer and an Improved Underdetermined Blind Source Separation Algorithm" by Alex Paul Hoffmann.