Performance of a Tightly-coupled GNSS/INS System Using the Latest Generation MEMS Sensors

摘要

NovAtel Inc. offers a high quality, tightly coupled GNSS/INS solution through its SPAN (Synchronized Position Attitude Navigation) product line. Historically, the SPAN GNSS/INS system has used traditional tactical grade IMUs, typically using FOG (Fiber Optic Gyro) or RLG (Ring Laser Gyro) technology. Recently however, MEMS (Micro Electrical Mechanical Systems) sensors have become increasingly viable for navigation purposes, with their greatly reduced size, weight, and cost comparing favourably to traditional sensors. Despite their recent advances, many challenges remain in utilizing MEMS technology to provide a robust navigation solution, particularly during limited GNSS availability. The measurement error characteristics of these devices have improved dramatically but are still much larger and more erratic than traditional sensors. This has necessitated innovative integration efforts to provide the robust solution expected from a GNSS/INS system. To demonstrate the performance of the SPAN solution using MEMS sensors, real world data will be presented using a selection of MEMS IMUs. This performance is then compared against a navigation grade IMU control.