GPS/INS

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

GPS/Pseudolite/INS integration: concept and first tests

Abstract: This paper discusses the introduction of pseudolites (ground-based GPS-like signal transmitters) into existing integrated GPS/INS systems in order to provide higher availability, integrity, and accuracy in a local area. Even though integrated GPS/INS systems can overcome inherent drawbacks of each component system (line-of-sight requirement for GPS, and INS errors that grow with time), performance is nevertheless degraded under adverse operational circumstances. Some typical examples are when the duration of satellite signal blockage exceeds an INS bridging level, resulting in large accumulated INS errors that cannot be calibrated by GPS. Such a scenario, unfortunately, is a common occurrence for certain kinematic applications. To address such shortcomings, both pseudolite/INS and GPS/pseudolite/INS integration schemes are proposed here. Typically, the former is applicable for indoor positioning where the GPS signal is unavailable for use. The latter would be appropriate for system augmentation when the number and geometry of visible satellites is not sufficient for accurate positioning or attitude determination. In this paper, some technical issues concerned with implementing these two integration schemes are described, including the measurement model, and the appropriate integration filter for INS error estimation and correction through GPS and pseudolite (PL) carrier phase measurements. In addition, the results from the processing of simulated measurements, as well as field experiments, are presented in order to characterize the system performance. As a result, it has been established that the GPS/PL/INS and PL/INS integration schemes would make it possible to ensure centimeter-level positioning accuracy even if the number of GPS signals is insufficient, or completely unavailable.

Fusion of GPS/INS/Odometer measurements for land vehicle navigation with GPS outage

Abstract: This paper deals with the hybridization of Global Positioning System (GPS) with an Inertial Navigation System (INS) and an Odometer, for land vehicle navigation, and more precisely with the calibration of inertial sensor errors. We focus here on the complementary characteristics of GPS and odometer to provide periodic corrections to Inertial Navigation System alternatively in different environmental conditions. In open sky, where GPS signals are available, GPS is integrated with INS. Meanwhile, in degraded GPS environments, where GPS is unreliable or unavailable, odometer replaces GPS to integrate with INS. This estimation problem is solved by a Kalman filter (KF), since it deals with non-linear problems and statistics.

Experimental system for validating GPS/INS integration algorithms

Abstract: Today most civil and military navigation systems are based on or include GNSS (Global Navigation Satellite System). In environments where buildings or foliage can block or seriously impede the p ...

Observability analysis of the INS/GPS navigation system on the measurements in land vehicle applications

Abstract: In this paper, the observability of the INS/GPS navigation system for a land vehicle is analyzed on measurements and different dimension filters with respect to the measurements are designed. In the stationary case, it is shown that the horizontal accelerometer biases and vertical attitude errors and gyro biases are unobservable. An 8 th filter is designed based on the observability analysis. When GPS signal is available, a 15 th filter is used with position and velocity measurements. To estimate the INS errors even in the case that GPS signal is blocked a filter is designed in consideration of the non-holonomic constraints of a land vehicle. In this case, the horizontal position and velocity errors and vertical attitude error are unobservable. However, a 12 th filter including the velocity states is designed to estimate the accelerometer biases. Based on the results of the observability analysis and the different dimension filters, an efficient INS/GPS filter including the filters as sub-filters can be designed.

GPS receiver capable of calculating accurate 2DRMS

Abstract: In the GPS receiver, GPS solutions are calculated by performing GPS measurement using a Kalman filter. The GPS receiver is provided with a computing system which calculates 2DRMS according to an equation: 2 DRMS =2×{square root over ((σ H — Kalman +L ) 2 +L +( HDOP×σ UERE +L ) 2 +L )} wherein, σH_Kalman represents a horizontal component of an estimate error obtained from a diagonal in an error covariance matrix calculated in a mathematical process of the Kalman filter, HDOP represents a horizontal dilution of precision, and σ UERE is a user equivalent range error.