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.

Apparatus and method for navigation of an aircraft

Abstract: In accordance with this invention, an apparatus and method for aircraft navigation are provided that utilize a blended architecture consisting of a global positioning system (GPS) and micro-electromechanical sensors (MEMS) for the primary navigation system and a laser gyroscope system for the secondary navigation system. The blended architecture of the present invention provides a navigation system that is at least as accurate, redundant and fault-tolerant as conventional navigation systems. In addition, the navigation system components may be distributed throughout the aircraft and may share computing resources with other avionics systems to process signals and provide data to the avionics systems. Overall, the navigation system of the present invention is significantly less expensive and easier to maintain, but equally or more precise and redundant, relative to conventional navigation systems.

Using High-Definition maps for precise urban vehicle localization

Abstract: Global Navigation Satellite Systems (GNSS) based localization in the context of Intelligent Transportation Systems, Advanced Driver Assistance Systems and ultimately the development of autonomous vehicles often requires accuracy with integrity. Low-cost data fusion algorithms for positioning that integrate GNSS and additional in-vehicle sensor information are able to handle short term GNSS outages and can provide increased availability and accuracy. Challenging are non-line-of-sight effects that are often present in urban areas. As those can hardly be modeled accurately, an unobservable position bias is often introduced which violates the estimated confidence. Therefor, mass-market applicable localization algorithms that mitigate their influence are desired to allow GNSS-based positioning for safety critical applications. With the beginning market introduction of high-definition maps (HD maps) by major map providers, another inexpensive tool to enhance data fusion based localization algorithms is available. Those maps offer means to further improve the accuracy and integrity of vehicle position estimation, especially in challenging urban environments. In this paper, a particle filter based localization algorithm is presented that integrates HD maps, GNSS and vehicle odometry measurements to demonstrate the benefits of HD maps using real world measurements.

Removing biases in dual frequency gnss receivers using sbas

Abstract: A method for removing biases in dual frequency GNSS receivers circumvents the need for ionosphere corrections by using L2(P) in combination with either L1(P) or L1(C/A) to form ionosphere-free ranges. A table of biases is stored in microprocessor controller memory and utilized for computing a location using corrected ionosphere-free pseudo ranges, A system for removing biases in dual frequency GNSS receivers includes a dual frequency GNSS receiver and a controller microprocessor adapted to store a table of bias values for correcting pseudo ranges determined using L2(P) in combination with either L1(F) or L1(C/A ).

Development and validation of an OFDM/DVB-T sensor for positioning

Abstract: The use of Global Navigation Satellite System (GNSS) for positioning has grown significantly in recent years thanks in particular to the development of several mass-market applications, such as car navigation or mobile positioning. Unfortunately, in difficult environments such as dense urban or indoor areas, GNSS exhibits degraded performances in terms of precision and availability. The use of signals of opportunity is one of the solutions to replace or assist GNSS in those environments. These signals are communication signals that are usually designed to provide a service in dense environment and can thus be used in location where GNSS is unavailable. Several commercial positioning services based on signals of opportunity already exist such as ROSUM with ATSC digital TV signals, or Skyhook with Wi-Fi signals

Low-cost sensors data fusion for small size unmanned aerial vehicles navigation and guidance

Abstract: A new integrated navigation system designed for small size Unmanned Aerial Vehicles (UAVs) is presented. The proposed system is based on a number of low-cost avionics sensors, including Global Navigation Satellite Systems (GNSS), Micro-Electro-Mechanical System (MEMS) based Inertial Measurement Unit (IMU) and Vision Based Sensors (VBS). The use of an Aircraft Dynamics Models (ADMs) to provide additional information to compensate for the shortcomings of Vision Based Navigation (VBN) and MEMS-IMU sensors in high-dynamics attitude determination tasks is also considered. Additionally, the research concentrates on the potential of carrier-phase GNSS for Attitude Determination (GAD) using interferometric techniques. The main objective is to design a compact, light and relatively inexpensive system capable of providing the required navigation performance (position and attitude data) in all phases of flight of small UAVs, with a special focus on precision approach and landing, where VBN techniques can be fully exploited in a multi-sensor data fusion architecture. An Extended Kalman Filter (EKF) is developed to integrate the information provided by the different sensors and to provide estimates of position, velocity and attitude of the UAV platform in real-time. Three different integrated navigation system architectures are implemented. The first architecture uses VBN at 20 Hz and GNSS at 1 Hz to augment the MEMS-IMU running at 100 Hz. The second mode also includes the ADM (computations performed at 100 Hz) to provide augmentation of the attitude channel. The third fusion architecture uses GNSS based attitude values. The simulations are carried out on the AEROSONDE UAV performing high-dynamics manoeuvres repre-sentative of the UAV operational flight envelope. Simulation of the VBN-IMU-GNSS (VIG) integrated navigation system shows that the system can attain position, velocity and attitude accuracies complying with Category Two (CAT II) precision approach requirements. Simulation of the VBN-IMU-GNSS-ADM (VIGA) system also shows promising results, since the achieved attitude accuracy is higher using the ADM-VBN-IMU than using VBN-IMU only. However, due to rapid divergence of the ADM virtual sensor, there is a need for frequent re-initialisation of the ADM data module, which is strongly dependent on the UAV flight dynamics and the specific manoeuvring transitions performed. In the simulation of the third integrated navigation system, the VIG system is augmented by employing the GAD, forming the VIG-GAD (VIGGA) system architecture. The performances achieved with the VIG, VIGA and VIGGA integrated Navigation and Guidance System (NGS) are presented and are in line with the International Civil Aviation Organization (ICAO) precision approach requirements.