Abstract: A positioning system is disclosed. The positioning system has a database for storing a site model. The site model has data indicative of a desired geography of a site environment and an actual geography of the site environment. The positioning system also has a first receiver for generating digital signals representing a real time position in three-dimensional space of at least a portion of a machine as the machine traverses the site environment. The positioning system further has a processor for receiving the signals and updating the site model to determine a difference between the data indicative of the desired geography and the data indicative of the actual geography. The positioning system also has a display for projecting the site model onto at least one surface of an operator station of the machine so that an operator may simultaneously view the site model and the site environment.