The Pagani True Interval Seismic Piezocones have a double set of geophones positioned at 50cm from each other which not only allows for more Seismic data to be collected in a simpler fashion but also very accurate (true) arrival time difference of a Seismic Wave.
The three Geophones for collecting the data on the Seismic Waves are positioned orthogonally between them, inside the piezocone unit, one for gathering data on the P waves and two for gathering data on the S waves, allowing for the data to be received from any angle.