A digital-type fluxgate magnetometer using a sigma-delta digital-to-analog converter for a sounding rocket experiment

Abstract

One of the design challenges for future magnetospheric satellite missions is optimizing the mass, size, and power consumption of the instruments to meet the mission requirements. We have developed a digital-type fluxgate (DFG) magnetometer that is anticipated to have significantly less mass and volume than the conventional analog-type. Hitherto, the lack of a space-grade digital-to-analog converter (DAC) with good accuracy has prevented the development of a high-performance DFG. To solve this problem, we developed a high-resolution DAC using parts whose performance was equivalent to existing space-grade parts. The developed DAC consists of a 1-bit second-order sigma-delta modulator and a fourth-order analog low-pass filter. We tested the performance of the DAC experimentally and found that it had better than 17-bits resolution in 80% of the measurement range, and the linearity error was 2−13.3 of the measurement range. We built a DFG flight model (in which this DAC was embedded) for a sounding rocket experiment as an interim step in the development of a future satellite mission. The noise of this DFG was 0.79 nTrms at 0.1–10 Hz, which corresponds to a roughly 17-bit resolution. The results show that the sigma-delta DAC and the DFG had a performance that is consistent with our optimized design, and the noise was as expected from the noise simulation. Finally, we have confirmed that the DFG worked successfully during the flight of the sounding rocket.

Vectorized magnetometer for space applications using electrical readout of atomic scale defects in silicon carbide

“…While not the most sensitive option for space bound magnetometers, fluxgate sensors are moderately stable and can exhibit high sensitivity . Sigma-delta ADC technology with improved sampling resolution has been leveraged to enhance sensitivity of this technology2021. Even though significant progress has been made to miniaturize these magnetometers22, the incorporation of a magnetically susceptible core wrapped with driving, sensing, and nulling coils for each axis will always limit the size and weight, and will never lead to a purely electrical device.…”

A Front-End ASIC for a 3-D Magnetometer for Space Applications by Using Anisotropic Magnetoresistors

“…However, the current trend of aerospace technology, which goes to the design of small-sized satellites to reduce costs, implies that the use of this type of magnetic field sensors is generally unaffordable owing to its volume and weight [2]. The use of application-specific integrated circuits (ASICs) instead of discrete electronics [3], [4] provides significant reductions in weight, volume, and power consumption, while maintaining the performance [5].…”