ABSTRACT
Early in the space age the global navigation satellite system (GNSS) was identified as a potential benefit of space. Accurate knowledge as to the location and velocity of spacecraft is essential for space activities. Global navigation satellite systems are space-based positioning and navigation systems designed to provide worldwide, all weather, three-dimensional position, and velocity and timing data. The service offered by GNSS can be viewed as being similar to the Internet. Both are global, easily accessible with appropriate technology, and, for many purposes, free. The use of GNSS has spread almost as quickly and as widely as that of the Internet, and the technology is developing rapidly. Of the GNSS systems only the European Galileo system is willing under certain circumstances to meet a claim for damages incurred by signal error. The GNSS is one of the major technological developments of our time.
