On-line Smoothing for Mobile Mapping Systems Utilizing a Low Cost MEMS IMU

For Land-based Mobile Mapping Systems (MMS) and navigation applications, the integration of Inertial Navigation System (INS) and Global Positioning System (GPS) is widely applied for determining position and orientation parameters. Due to low cost and small size, the Micro-Electro Measurement System (MEMS) inertial sensor is attractively utilized for commercial MMS. However, since the large bias and scale factor is still the main disadvantage of the MEMS sensor, the positional error of the system grows quickly over time in GPS denied environments. This issue takes place frequently when a land based MMS operates in GNSS hostile environment such as urban area or passing tunnels where the GPS signal is weak or completely blocked. To overcome that problem, this paper introduces on-line smoothing algorithm, which can utilizes the advantages and overcome the limitation of Kalmal filter and off-line Rauch-Tung-Striebel smoother to improve the performance of MMS utilizing low cost MEMS IMU.