PERFORMANCE ANALYSIS OF MULTI-GNSS SYSTEM BASED ON DOP, INTEROPERABILITY AND RAIM WITH A NEW APPROACH TO GNSS BASED TRACKING SYSTEM

Abstract

Global Navigation Satellite System (GNSS) is basically a system of satellites providing autonomous geo spatial positioning with global coverage. There are mainly four GNSS systems currently in operation. They are the United States’ Global Positioning System (GPS), Russian Federation's Global Orbiting Navigation Satellite System (GLONASS), Chinese BeiDou Navigation Satellite System (BDS) and European Galileo. Navigation basically means any of several methods of determining or planning an object’s position and course by geometry, astronomy, radio signals etc. This combines two concepts. The first is the determination of the position and velocity of a moving body with respect to a known reference, sometimes known as the science of navigation. The second is the planning and maintenance of a course from one location to another while avoiding obstacles and collisions. GNSS constellation is very important in determining these things. More precisely the Dilution of Precision plays a vital role in accuracy of the navigation system. Interoperability means combining information (pseudorange measurements, navigation data) from two or more GNSS systems at the user receiver to achieve better performance than employing either system separately. Monitoring the integrity of a navigation system is essential to ensure that the navigation solution is within tolerable constraints. Receiver Autonomous Integrity Monitoring (RAIM) refers to integrity monitoring of GNSS navigation signals performed by a receiver independent of external reference systems. A multi constellation context due to the introduction of Galileo and GPS, great improvement could be expected from RAIM performance. Recognizing the strategic importance Galileo has the provision to be interoperable with GPS. The efficiency of any GNSS system depends largely on the receiver available at the user end. In this thesis GNSS receivers are discussed in detail and next generation GNSS receivers are illustrated briefly. A new indoor GPS tracking system is proposed in our thesis. This system integrates positioning technology, user interface and dynamic information provision. We have shortly discussed this system in the 4th floor of Tower Building-1 of MIST. The whole system is currently a proposed idea and we are hoping to see its effective implementation in the near future