Performance Analysis of Integrated Navigation System INS/GPS/Mag. /Baro

This article reviews the structure of an integrated navigation system made up of unit inertial sensors manufactured by MEMS technology, a GPS Receiver unit, magnetic compasses manufactured by MEMS technology, and a high barometric sensor. The integrated system is built using an Extended Kalman Filter (EKF). This reviewing is performed with the use of a closed-loop system that has simple integration namely the Loosely Coupling Integration. After conducting several air tests to collect real navigational data, antipersonnel navigational data has been used to do the integrated navigation system analysis with EKF environment in the software Matlab. It has been noticed after the analysis that the complementary horizontal navigation system error does not exceed 50 m. With deliberate withholding of GPS data for different periods in order to test the performance of the integrated navigation system in case of withholding the GPS signal, we have found that the integrated navigation system achieves good accuracy, where the horizontal error does not exceed 200 m value when the withholding GPS data for 120 seconds. This can be considered as small and acceptable values compared with the horizontal error value for inertial navigation unit stim300 when operating independently of up to 8200 m.

Developing a position estimation algorithmin GNSS-Precise Point Positioning technique depending on Extended Kalman Filter

Precise point positioning technique uses recursive algorithms to solve the navigation problem. In fact, traditional least square method doesn’t meet the requiredassessments of processing speed, and quality in different geodetic and surveying applications,due tobig amount of output processing data provided by global navigation satellite systems. Extended Kalman filter is considered as optimal solution approach of the navigation problem. This filter requiresthe knowledge of measurements, its observational models, and physical state for estimation problem like: (receiver dynamic, received signals characters, and suitable estimation of its initial conditions). Research refers to a mathematical suggestion, which reduce the negative effect of convergence time at EKF initial conditions. This work also shows how a position estimation accuracy affected by the suggested modification of using EKF in PPP, and supporting the use ofthis modification in position estimation field, in spite of increasing processing time.