Introduction to Global Navigation Satellite Systems and Its Errors

Abstract

Global Navigation Satellite Systems (GNSS) include different parts such as control and monitoring stations for the Earth and space settings. Timing, positioning, and control of navigation methods are the main outputs of GNSS. Based on Approach Procedure with Vertical guidance (APV), local and global satellite navigation systems used for positioning and precision approach in aviation instead of present systems like Instrumental Landing Systems (ILS) and its future predict of ICAO. According to ASBU, development of present systems in new flight instructions must include GNSS because flight capacity increase significantly through it. But these systems have errors in positioning and velocity measurement segments. Different methods exist in view point of installing earth antennas and satellite position to reduce estimation errors. In this paper two methods was studied