An algebraic method for compensating for coil-placement errors in three-dimensional search-coil eye trackers

A method for compensating for coil-placement errors in three-dimensional scleral search-coil eye trackers is described. The position of the coils may be measured exactly and simply. The error-compensation method avoids the use of difficult transcendental equations by expressing eye position as a linear combination of coil position vectors. The coil position vectors are considered to form a rigid, nonorthogonal basis in the frame of reference of the globe. The constants relating eye position to this basis can be derived from a calibration session