Precise Satellite Navigation by Means of the Global Positioning System NAVSTAR-GPS

The basic concept of the NAVSTAR - GPS radio navigation system is reviewed. The advantages of this spaceborne system over terrestrial radio positioning systems are discussed. The features of this fully coherent, PRN- modulated, two frequency systems are described. GPS can be used for very precise position and velocity determination as well as for precise attitude measurements and time transfer. Apart from military use many civilian applications in the areas of transportation, surveying, geoscience etc. are possible and then will benefit considerably from this new tool. The present experimental state of GPS allows already many performance demonstrations and practical applications of the high quality of this system. The operational system be deployed in the next years.