I don't know how to go about solving a direction of arrival problem and hoping someone here does. If I have an array of acceleration sensors (say, Analog Devices ADXL193) and I know their position and orientation (say they are mounted to a rigid spherical surface), it seems I should be able to analytically calculate the direction (and magnitude?) of arrival of an impact to the rigid surface. Can anybody provide an algorithm or some code that will do this? Thanks. Part 2 of the question. It seems that I need at least 4 acceleration sensors, at least one non-co-planar with the others, to avoid ambiguity. Confirm?