Work Description

Title: Quad-Mag Sensor Characterization Data
Author: Brady P. Strabel
Contact: Brady P. Strabel bstrabel@umich.edu
Grant: NASA 80NSSC18K1240 and NASA 80NSSC19K0608 and NSF AGS 1848724

The data contained in the file comprises those collected during the characterization of the sensor as described in:

Strabel, B. P., Regoli, L. H., Moldwin, M. B., Ojeda, L. V., Shi, Y., Thoma, J. D., Narrett, I. S., Bronner, B.,
and Pellioni, M.: Quad-Mag board for CubeSat applications, Geosci. Instrum. Method. Data Syst., 11, 375–388,
https://doi.org/10.5194/gi-11-375-2022, 2022.

Research overview:

The paper presents a characterization of a four-magnetometer board for Cubesat
applications. The magnetometer used is the PNI RM3100, a low-cost, low-power COTS
sensor ideal for small spacecraft applications.

The research presented in the paper was conducted from 2018-2022 at the Department of Climate
and Space Sciences and Engineering.

Methods:

The data used in this study were collected using four PNI RM3100 magnetometers sampling
at a frequency of 65 Hz.The data were collected in the copper room located in the
Space Research Building in Ann Arbor, MI, USA using a program written
in Python language and analyzed using both Matlab and Python.

File inventory:

The data are contained in the .zip files. Quad_Mag_Data.zip is the original version of the data, which is deprecated; Quad_Mag_Data_UPDATED.zip contains additional data added as part of the peer review process, and is the dataset corresponding to the published paper. The compressed files contain several folders:

The Stability folder contains the 38 Hours of data for the instrument stability analysis (section 4.4).

The Sensitivity folder contains the data used for the resolution analysis in the paper (section 4.3).

The Interference folder (included only in the UPDATED data) contains the data used for board/mutual magnetometer interference analysis (section 4.5)

Variables:

The file Interference/influence_72hz_No_Board.txt has measurements from a single magnetometer and thus
does not follow the exact format of the other files. The header contains the same information as outlined
below, but there are only four columns: timestamp followed by the magnetic field components
in the x, y, and z directions.

For the remaining files, there is first a header that gives the necessary parameters for converting
from lsb to nT for the magnetometers. Following this header, each of the columns are labeled with
what each represent. The first column is a packet flag that can be largely ignored. The second column
corresponds to the system time from startup and is used as the timestamp of a reading. Following this, each
magnetometer X-, Y-, and Z-components of the magnetic field are printed (3 axis * 4 magnetometers). The
values are raw and need to be converted out of lsb form which can easily be done by multiplying each of the
magnetometer readings with the following scale factor:

sf = 1000 / (0.3671 * cycle_counts + 1.5) / oversampling

The cycle_counts and oversampling can be found in the header of the file. For the paper, these were set to 400
and 1 respectively. This results in a scale factor of 6.74 nT/lsb.

Use and Access:
This data set is made available under a Attribution 4.0 International License (CC BY 4.0).

To Cite Data:
Strabel, B. P.: Quad-Mag Characterization Data, https://doi.org/10.7302/KC6T-3670, 2022