Magnetometer Characterization as Fundamental for Non-Cryogenic Biomagnetic Sensing - Handout BIOMAG 2026 : Minimum Detectable Signal (MDS) and MDS20
This handout accompanies the BIOMAG 2026 talk “Magnetometer Characterization as Fundamental for Non-Cryogenic Biomagnetic Sensing”. It derives the minimum detectable signal (MDS) as an application-oriented figure of merit that combines intrinsic magnetic noise with source-to-sensor distance. Using a rotating magnetic dipole model, the minimum detectable dipole moment is expressed in terms of the noise power spectral density, bandwidth, required signal-to-noise power ratio and distance between the source and the sensing center. This distance includes the external source-to-sensor-case distance and the internal stand-off distance. For comparison, under harmonized and defined conditions, MDS20 is specified using a signal-to-noise power ratio of 20 (approx. 13 dB), an external distance of 20 mm and a bandwidth of 1 Hz. The noise power spectral density is averaged over a 1 Hz band centered at 20 Hz. Supplementary slides from the talk illustrate the trade-off between sensor noise and source-to-sensor distance and compare selected superconducting quantum interference devices (SQUIDs), optically pumped magnetometers (OPMs), magnetoresistive (xMR) sensors, magnetoimpedance (MI) sensors, nitrogen-vacancy (NV) center magnetometers, and magnetoelectric (ME) sensors. The handout highlights the relevance of both noise and stand-off distance when assessing the detectability of sources.
Preview
Rights
Use and reproduction:
Please note that individual components of the publication may be subject to other licensing or copyright conditions.