GPS/INS

About: GPS/INS is a research topic. Over the lifetime, 3554 publications have been published within this topic receiving 62784 citations.

On the capability of high sensitivity GPS for precise indoor positioning

Abstract: High-sensitivity GPS receivers allow to track very weak GPS signals (-180 dBW or even below) that are due to strong signal attenuation by e.g. foliage or constructive materials. Consequently, they outperform classical geodetic receivers of more than 30 dB and enable the signal tracking and positioning even indoors. This increase of GPS availability opens up new applications such as seamless outdoor-indoor positioning and navigation. However the positioning accuracy is often poor. In this paper, we use an exemplary data set from our GPS indoor test network to analyse the capability of high sensitivity GPS receivers for precise indoor positioning. A general study of the performance parameters (e.g. DOP factors, C/No-values) gives a first impression of the improved availability. The detailed analysis of the observed-computed values of the pseudo-ranges quantify the indoor delay which can reach up to 100 m. Considering the positioning solution, it is shown that a C/N0- based signal weighting can improve the accuracy of about 70 % for the mean value over 40 min observation time and up to 40% for the scatter of the coordinate time series.

Loosely Coupled INS/GPS Integration with Constant Lever Arm using Marginal Unscented Kalman Filter

Abstract: A loosely coupled Inertial Navigation System (INS) and Global Positioning System (GPS) are studied, particularly considering the constant lever arm effect. A five-element vector, comprising a craft's horizontal velocities in the navigation frame and its position in the earth-centred and earth-fixed frame, is observed by GPS, and in the presence of lever arm effect, the nonlinear observation equation from the state vector to the observation vector is established and addressed by the correction stage of an unscented Kalman filter (UKF). The conditionally linear substructure in the nonlinear observation equation is exploited, and a computationally efficient refinement of the UKF called marginalized UKF (MUKF) is investigated to incorporate this substructure where fewer sigma points are needed, and the computational expense is cut down while the high accuracy and good applicability of the UKF are retained. A performance comparison between UKF and MUKF demonstrates that the MUKF can achieve, if not better, at least a comparable performance to the UKF, but at a lower computational expense.

Experimental Results on an Integrated GPS and Multisensor System for Land Vehicle Positioning

Abstract: Global position system (GPS) is being widely used in land vehicles to provide positioning information. However, in urban canyons, rural tree canopies, and tunnels, the GPS satellite signal is usually blocked and there is an interruption in the positioning information. To obtain positioning solution during GPS outages, GPS can be augmented with an inertial navigation system (INS). However, the utilization of full inertial measurement unit (IMU) in land vehicles could be quite expensive despite the use of the microelectromechanical system (MEMS)-based sensors. Contemporary research is focused on reducing the number of inertial sensors inside an IMU. This paper explores a multisensor system (MSS) involving single-axis gyroscope and an odometer to provide full 2D positioning solution in denied GPS environments. Furthermore, a Kalman filter (KF) model is utilized to predict and compensate the position errors of the proposed MSS. The performance of the proposed method is examined by conducting several road tests trajectories using both MEMS and tactical grade inertial sensors. It was found that by using proposed MSS algorithm, the positional inaccuracies caused by GPS signal blockages are adequately compensated and resulting positional information can be used to steer the land vehicles during GPS outages with relatively small position errors.