Enhancement of INS Initial Alignment Estimation Using Wavelet De-Noising Method

Inertial Navigation Systems (INS) is now utilized in various of applications covering the navigation of cars, ships, aircraft, spacecraft. It utilized to process the accelerations and angular velocity signals of an inertial measurement unit (IMU) to estimate the position, velocity, and attitude of a vehicle. One among the most important significant sources of inaccuracy for precise INS is an error in determining initial attitude. To ensure accurate estimations of the velocity, position, and orientation of a moving object, the initial orientation angles must be accurately estimated. Alignment techniques refers to the process of calculating the initial attitude angles. In this paper, before employing the inertial sensor measurements for initial alignment, multiple levels of wavelet decomposition (LOD) using the wavelet de-noising technique are used to eliminate the components of high frequency noise. The proposed technique is tested using real data sets from crossbow IMU MEMS sensors collected laboratory using turn table with high vibrations. The results show enhancement in the accuracy calculations of initial alignment using the estimation method.