Array processing of infrasound data uses the coherency between sensors to calculate directions of incoming waves. The Cabauw Infrasound Array (CIA) provides unique opportunities for infrasound processing. Because unlike most infrasound arrays, CIA has sensors with height differences. Specifically sensors distributed on a 200m tall tower. But the data from these tower sensors are of limited use for time-domain array processing due to the measurement of both the incoming wave and its reflection. To make the measurements suitable for array processing the reflection needs to be removed. The ground measurements are used to approximate the waveform and a time-shifted ground average is removed from the tower measurements. The new cleaned data was successfully used for full 3D array processing.