PiCUS Sonic Tomograph
The PiCUS works by taking readings of the velocity of sound waves through the stem from several sensors. Small nails are used to install the sensors around the trunk and each sensor is struck in turn to pass sounds waves through the tree. The result is recorded and computed to provide a full colour Tomogram (visual picture of the readings), which gives an indication of the consistency of the wood within the tree, and whether or not there is decay present. Multiple tests at various heights can produce data to build a 3D image of the level of decay.