Quad-Mag board for CubeSat applications

The design, characteristics, and performance of a CubeSat magnetometer board (Quad-Mag) equipped with four PNI RM3100 magnetometers is presented. The low size, weight, power, and cost of the RM3100 enables the inclusion of four sensors on a single board, allowing a potential factor of 2 reduction in the noise floor established for an individual sensor via oversampling with multiple sensors. The instrument experimentally achieved a noise floor of 5.34 nT (individual axis), averaging across each axis of the four magnetometers, at a 65 Hz sampling rate. This approaches the theoretically established limit for the system of 4.37 nT at 40 Hz. A single onboard Texas Instrument MSP430 microcontroller handles synchronization of the magnetometers and facilitates data collection through a simple UART-based command interface to a host system. The Quad-Mag system has a mass of 59.05 g and total power consumption of 23 mW while sampling and 14 mW while idle. The Quad-Mag enables nearly 1 nT magnetic field measurements at 1 Hz using commercial off-the-shelf sensors for space applications under optimal conditions.