Synthetic Aperture Magnetometry
Encyclopedia
Synthetic-aperture magnetometry (SAM) is a method for analysis of data obtained from magnetoencephalography
(MEG) and electroencephalography
(EEG). SAM is a nonlinear beamforming
approach which can be thought of as a spatial filter
.
Magnetoencephalography
Magnetoencephalography is a technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring naturally in the brain, using arrays of SQUIDs...
(MEG) and electroencephalography
Electroencephalography
Electroencephalography is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain...
(EEG). SAM is a nonlinear beamforming
Beamforming
Beamforming is a signal processing technique used in sensor arrays for directional signal transmission or reception. This is achieved by combining elements in the array in a way where signals at particular angles experience constructive interference and while others experience destructive...
approach which can be thought of as a spatial filter
Spatial filter
A spatial filter is an optical device which uses the principles of Fourier optics to alter the structure of a beam of coherent light or other electromagnetic radiation. Spatial filtering is commonly used to "clean up" the output of lasers, removing aberrations in the beam due to imperfect, dirty,...
.