To help the contractor determine where dirt needs to be scraped off or filled in, Trimble, Sunnyvale, Calif., has a new suite of 3-D grade control systems that use the Global Positioning System (GPS). The Trimble GCS family of grade control systems provides upgrade options that deliver earthmoving contractors the flexibility to select a system that meets their daily needs. For example, a single-control system such as the GCS300 can provide low-cost entry into grade control and over time can be upgraded to the GCS400 dual-sensor system or to the full 3-D GCS900. The GCS family uses the industry-standard Controller Area Network as the backbone of the system to connect laser receivers, sonics or GPS sensors and the control box to the machine hydraulics.