Trimble's new version of its widely used SiteVision GPS system is designed for use on hydraulic excavators equipped with a tilt-bucket attachment. The new system, says Trimble, "measures the three-dimensional position of both bucket tips", and thus allows the machine to work on sloped planes, such as trenches with sloped sides. Sensors mounted on the boom, stick and tilt-bucket linkage report the relative position of the bucket's teeth, and this information, coupled with GPS positioning, is used to calculate an accurate three-dimensional position and orientation.