GNSS augmentation

About: GNSS augmentation is a research topic. Over the lifetime, 2478 publications have been published within this topic receiving 28513 citations. The topic is also known as: SBAS & Satellite Based Augmentation System.

A key management architecture for GNSS open service Navigation Message Authentication

Abstract: Navigation Message Authentication (NMA) is a necessary security provision in GNSS open service, considering that more and more infrastructures rely on civilian GNSS signals, and several cryptographic mechanisms have been proposed to implement it. Most solutions adapt existing protocols to the specific requirement and constraints of the GNSS scenario, which is inherently one-way and asymmetric, and hence make use of asymmetric cryptography. However, no similar proposal has yet been made for the provision of key management services (distribution, upgrade, revocation), which are crucial for the security of any cryptographic mechanism.

Satellite-based automatic steering system

Abstract: Methods, systems, and machine-interpretable coding for causing a processor of a vehicle controller installed in a vehicle such as a rubber-tired gantry (RTG) to generate, using known position associated with a base station and signals received from a Global Navigation Satellite System (GNSS) receiver located at the base station, a satellite observation error estimate; generate, using the satellite observation error estimate and a position of vehicle determined using signals received from a GNSS receiver mounted on the vehicle, at least one control signal representing a navigation command executable by at least one control device of the vehicle; and to output the control signal for execution by the control device. Generation of control signals can include use of synchronous and asynchronous processing, ambiguity resolution processes, and as fuzzy logic and PID and other control feedback loops.

Cost-effective precise positioning using carrier phase navigation-grade receiver

Abstract: The market for Global Navigation Satellite System (GNSS) based applications requiring accurate positioning information has been steadily growing over the recent years. As a consequence of technological advances in GNSS technology, single-frequency, navigation-grade receivers capable to provide carrier phase data can be a cost-effective alternative to the high-professional, geodetic-grade receivers. Navigation-grade receivers are mainly attractive as their cost ranges around of few hundred euros. In addition, the carrier phase measurements are the most accurate observables collected from a GNSS system. As a result, the positioning accuracy obtained with navigation-grade receivers can reach levels that may raise interest various communities that use positioning information. The main purpose of this study is to analyze the performance of high-sensitivity carrier phase-based positioning using navigation-grade equipment. A few static tests covering different time intervals and various baselines with different lengths are investigated. In addition, several kinematic tests are also conducted. The obtained positioning solutions and baseline lengths are compared to the corresponding ones derived from observations collected with professional equipment. The test results demonstrate that cm-level accuracy can be achieved with navigation-grade equipment when it can output carrier phase data. This level of accuracy may be attractive to various applications, such as land, marine or aerial surveying, structural monitoring or early warning systems.

Sensor fusion for GNSS denied navigation

Abstract: We present technologies that are being developed to address the need for a navigation solution in the absence of Global Navigation Satellite Systems (GNSS) measurements. The navigation system uses sensors such as vision systems, RADARS and LIDARS with feature extraction, matching and motion estimation algorithms. We present experimental results of using scale invariant feature transform, speeded up robust features, and modified Harris feature extraction algorithms and compare the performance. We also present methods to extract lines and planes that can aid in navigation. For motion estimation we present results for visual odometry as well as simultaneous localization and mapping navigation. We experimentally verify the algorithms in both a realtime Linux framework as well as offline. We also present ongoing work in vision integrated navigation in an attitude and heading reference system as well as an extended Kalman filter framework. All the methods we present in this paper are incremental navigation methods.

Low-cost GNSS/INS/Odometric Sensor Fusion Platform for Ground Intelligent Transportation Systems

Abstract: For many applications in Intelligent Transport Systems (ITS), the position and heading information of vehicles and Vulnerable Road Users (VRU) cannot generally rely on the performance of the Global Navigation Satellite System (GNSS) as a standalone technology. Even with the use of precise positioning techniques and augmentation systems for GNSS, such as Space-based Augmentation System (SBAS) or Differential-GNSS, its performance and its availability still depends on the signal propagation conditions (e.g. multipath, unintentional or intentional (jamming) interferences, or visibility of satellites). The urban canyon represents one of the most challenging scenarios for GNSS standalone positioning, being a scenario where ITS users usually require the highest performance. This paper discusses the design, implementation and performance validation of multisensor positioning based on GNSS, Inertial Measurement Units (IMU), and Odometric information for ground ITS applications. Bayesian sensor fusion algorithms are discussed and loose and tight GNSS/INS coupling compared. Additionally, these algorithms are enhanced by exploring the application of dynamic noise covariance matrices, including non-holonomic constraints to the vehicle’s movement, and by adding a zero velocity update IMU calibration algorithm using the vehicle’s speedometer measurements. The algorithms performance was extensively evaluated in both simulation and in real-life experiments. The algorithms are validated in a low-cost prototype implementation. The prototype receiver, operating in real-time, is based on the popular Raspberry PI3 platform, a dual-IMU MEMS peripheral and a consumer-grade GNSS receiver. The paper includes a discussion of the implementation trade-offs, challenges, and adopted solutions. A measurement campaign where the developed prototype was mounted on a vehicle is discussed, showing the potential of this approach.