A system is disclosed that uses GPS and additional data to determine the location of an object. Typically, GPS receivers need valid data from four satellites to accurately determine a three dimensional location. If a GPS receiver is receiving valid data from fewer than four satellites, then additional data is used to compensate for the shortage of satellites in view of the GPS receiver. Examples of additional data includes a representation of the surface that the object is traveling on, an accurate clock, an odometer, dead reckoning information, pseudolite information, and error correction information from a differential reference receiver. An exemplar use of the disclosed system is to concurrently track a set of one or more automobiles during a race. The determined locations of the automobile can be used to provide route information, to generate statistics and/or to edit video of one or more of the automobiles.