Satellite Technology: Principles and Applications, 3rd Edition

13Navigation Satellites

Navigation is the art of determining the position of a platform or an object at any specified time. Satellite-based navigation systems represent a breakthrough in this field that has revolutionized the very concept and application potential of navigation. These systems have grown from a relatively humble beginning as a support technology to that of a critical player used in a vast array of economic, scientific, civilian and military applications. Two main satellite-based navigation systems in operation today are the Global Positioning System (GPS) of the USA and the Global Navigation Satellite System (GLONASS) of Russia. The GPS navigation system employs a constellation of 24 satellites and ground support facilities to provide the three-dimensional position, velocity and timing information to all the users worldwide 24 hours a day. The GLONASS system comprises 21 active satellites and provides continuous global services like the GPS. These navigation systems are used in various domains such as surveying and navigation, vehicle tracking, automatic machine guidance and control, geographical surveying and mapping and so on. The chapter gives a brief outline on the development of satellite-based navigation systems and a descriptive view of the fundamentals underlying the operation of the GPS and GLONASS navigation systems and the future trends in satellite based navigation systems.

13.1 Development of Satellite Navigation Systems

Various navigation methods ...