f Seismic imaging at the Whitchester test site using cross-hole data

The Imperial College test site at Whitchester consists of a group of four near-vertical boreholes of approximately 250 metres depth. These have been extensively logged and are now cased. A crosshole seismic dataset has be collected between boreholes 1 and 2 over a depth range of 50 to 120 metres. The holes are 25 metres apart. The sources were detonator caps fired at 2 metre intervals, and the signals were recorded with a twelve-component hydrophone streamer. The data contain frequencies in excess of 1.5kHz, with peak energy around 800Hz in the early arrivals. Despite severe contamination by tube waves the data are suitable for use in a variety of imaging algorithms.