PSD Units ofr Magnetometer and Gradiometer

Dear all,

After calculating PSD using Welch's method for MEG data, the identical unit is used for magnetometer and gradiometer. However, magnetometers measure in the unit [T] and gradiometers in the unit [T/m]. Should not then also the unit in the PSD differ or is corrected for this?


You can notice the same for the recordings, we use only the T units for the gradiometers. For displaying the MEG recordings interactively, we use a scaling factor to "convert" the gradiometers from T/m to T.
See this tutorial section: Tutorials/TutMindNeuromag - Brainstorm

However, this correction is not applied when applying processes on these recordings.
Therefore, the PSD is computed from the values in T/m, and the units displayed in the figure are incorrect.

@John_Mosher Is this correct?