Integrated GPS‐INS for High‐Accuracy Road Positioning

Abstract

The use of a differential global positioning system (GPS) for high‐accuracy road positioning has shown some limitations in terms of outages due to satellite masking that cause poor geometry and loss of carrier phase lock. By integrating a GPS receiver to an inertial navigation system (INS), i.e., GPS/INS, these limitations can be overcome to a large degree. The concept of GPS/INS for positioning is discussed with the emphasis on accuracies at the centimeter level, and an effective cycle‐slip detection and correction strategy using INS is also presented. GPS/INS data collected on a highway near Calgary is used to assess the feasibility of the system in terms of accuracy and reliability. GPS outages are simulated to determine their effect on the accuracy and cycle‐slip detection/correction capabilities. Results show that accuracies of 5 cm are achievable with this system; however, a degradation in performance can be expected when GPS outages occur. A discussion of improved modeling techniques as well as the many applications of this system concludes the paper.