Improvements in the accuracy of GPS measurements under poor operating conditions

GPS (Global Positioning System) is a three-dimensional positioning system that makes use of the latest satellites, enabling the measurement of the user's current location at any time. The use of GPS is common throughout the world, and the term 'GPS' is widely known because of the fact that GPS receivers are mounted in various devices such as car navigation systems and cell phones. There are a number of different types of GPS: standard positioning service (SPS), differential GPS (DGPS), and interference GPS. Although interference GPS has a high degree of accuracy, it requires substantial infrastructure. In contrast, although SPS and DGPS require little infrastructure, they offer less accurate positioning. If SPS and DGPS can be improved to provide a higher degree of accuracy in terms of positioning, they will be employed in more applications relevant to our daily lives than ever before. Bias errors in SPS and DGPS increase when positioning is carried out under poor operating conditions. As GPS positioning is computed from the pseudo-range from each satellite, the satellite arrangement and range in error pseudo are important in terms of improving the accuracy of GPS. In this paper, we undertake an experiment and simulation with the aim of improving the bias error of GPS under poor operating conditions.