Introduction

One of the works of the cross-hole SEP subseminar during the summer quarter, 1990 was processing 3-component data obtained using an experimental borehole vibrosource. In (Cole and Karrenbach,1990) the ``rotation" of the data is described. Technically the rotation is transformation of the coordinate system and respectively the components of the data; new axes were chosen the following way: 1) along the direction source-receiver, 2) normal to the first axis in the vertical plane, 3) perpendicular to the vertical plane. The purpose of such processing is separating the waves with different types to have more chances to detect the possible presence of SH-wave. Beyond the rotation Cole and Karrenbach also estimated the wavelet and I used their estimate to make deconvolution of the data. The idea was that after such processing it would be possible to see SH-wave.