A20 VIBRATOR SOURCE SIGNAL ESTIMATION BY DATA COMBINATION Abstract 1 There is a vibratory source signal estimation technique which is based on the combination of two types of data. They are the measured vibratory acceleration data and the relative information calculated from geophone signals. It has been shown before that the fundamental part of the measured ground force signal – derived from the acceleration functions – can be used to approximate the far field displacement velocity function. Since the higher harmonics are not represented properly especially the odd ones they are estimated from the direct arrivals of the uncorrelated field