GPS assisted Standard Positioning Service for navigation and tracking: Review & implementation

The potential ability of Global Positioning System (GPS) to assist navigating and tracking application facilitates in determining precise object positioning on earth. In order to efficiently execute tracking operation, GPS is dependent on various parameters viz. reliability of RF communication link, satellite geometry, GPS antenna placement, parameters to decode NMEA (National Marine Electronics Association) format that the GPS receiver obtains etc. All the information gathered is then analyzed to accurately track the object in real-time. This paper deals with the comprehensive study of GPS space segment and Control segment. Initially, the specification of GPS service known as Standard Positioning Service (SPS) ranging signal characteristics is introduced. Further, a detailed overview of GPS navigation message format, satellite tracking and selection process, frequency planning, C/A code generation and timing is studied and illustrated. Also, the user end implementations of location measurement processing algorithms are discussed. Hence, all the location information is used along with survey maps and object control actuators to support navigation. Furthermore, paper briefly describes the implementation of the real time position tracking system.