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.

Design of an UWB indoor-positioning system for UAV navigation in GNSS-denied environments

Abstract: Commonly used unmanned aerial vehicle (UAV) platforms rely on the use of global navigation satellite system (GNSS) receivers for navigation. To enable the autonomous navigation of cooperative UAVs in GNSS-denied environments, the use of an ultra-wideband (UWB) positioning system is proposed. This paper discusses the design and evaluation of a practical and cooperative UWB positioning system using newly available integrated radio frequency hardware and antennas. Constellation-aware parameters, as well as other effects like antenna characteristics, are taken into consideration. A non-line-of-sight rejection is implemented based on the ratio of the first path compared to the power of the cumulated channel impulse response. An experiment covering a range of positions and orientations is conducted to gain a broad, representative set of results to assess the system accuracy in real-life usage. In a first experiment the system performance achieves a root-mean-square error of under 10 cm in the horizontal plane and under 20 cm in the three-dimensional space with a probability of 95 %. A GNSS emulation system is implemented to evaluate the real-time in-flight use of the UWB positioning system on an experimental UAV carrier. A proof of concept is given that the GNSS emulation may be used with commercially available UAV platforms to augment those systems with indoor navigation capabilities.

The Lambda Method for the GNSS Compass

Abstract: Global Navigation Satellite System carrier phase ambiguity resolution is the key to high precision positioning and attitude determination. In this contribution we consider the GNSS compass model. We derive the integer least-squares estimators and discuss the various steps involved in the ambiguity resolution process. This includes the method that has successfully been used in (Park and Teunissen, 2003). We emphasize the unaided, single frequency, single epoch case, since this is considered the most challenging mode of GNSS attitude determination.

Protecting GNSS Receivers From Jamming and Interference

Abstract: Critical government and industry sectors (such as law enforcement, transportation, communication, and finance) are growing increasingly dependent on Global Navigation Satellite Systems (GNSS) for positioning, navigation, and timing. At the same time, the availability of low-cost GNSS jamming devices are presenting a serious threat to GNSS and increasing the likelihood of outages to infrastructures relying on GNSS. The attacks range from malicious parties intentionally jamming GNSS signals within a targeted geographical region to uninformed users causing accidental interference. This paper is an overview of different approaches adopted to date to mitigate GNSS disruption caused by intentional and unintentional jamming. The first approach outlined in this paper is the use of inertial systems to aid GNSS. The second and third approaches are the filtering of jamming/interference in the spatial and time-frequency domains, respectively. The fourth approach is vector tracking of GNSS signals in the receiver.

Navigation system and methods for route navigation

Abstract: Embodiments of the present invention include systems and methods for improved navigation using the global positioning system (GPS). A method of improved navigation includes transmitting a destination to a navigation server through a wireless communication channel. The method further includes transmitting position information from a GPS-enabled device to the navigation server through the wireless communication channel automatically at a time interval. The method further includes generating navigation information by the navigation server. The navigation information is based on the position information and the destination. The method further includes receiving navigation information on the GPS-enabled device from the navigation server through the wireless communication channel.

A software radio approach to global navigation satellite system receiver design

Abstract: The software radio has been described as the most significant evolution in receiver design since the development of the superheterodyne concept in 1918. The software radio design philosophy is to position an analog-to-digital converter (ADC) as close to the antenna as possible and then process the samples using a combination of software and a programmable microprocessor. There are a number of important advantages to be gained through full exploitation of the software radio concept. The most notable include: (1) The removal of analog signal processing components and their associated nonlinear, temperature-based, and age-based performance characteristics. (2) A single antenna/front-end configuration can be used to receive and demodulate a variety of radio frequency (RF) transmissions. (3) The software radio provides the ultimate simulation/testing environment. Global Navigation Satellite Systems (GNSSs) are the latest and most complex radionavigation systems in widespread use. The United States' Global Positioning System (GPS) and, to a lesser extent, the Russian Global Orbiting Navigation Satellite System (GLONASS) are being targeted for use as next generation aviation navigation systems. As a result, it is critical that a GNSS achieve the reliability and integrity necessary for use within the aerospace system. The receiver design is a key element in achieving the high standards required. This work presents the complete development of a GNSS software radio. A GNSS receiver front end has been constructed, based on the software radio design goals, and has been evaluated against the traditional design. Trade-offs associated with each implementation are presented along with experimental results. Novel bandpass sampling front end designs have been proposed, implemented and tested for the processing of multiple GNSS transmissions. Finally, every aspect of GNSS signal processing has been implemented in software from the necessary spread spectrum acquisition algorithms to those required for a position solution. The GNSS software radio is the first of its kind and will thus bring all the assets associated with the concept into GNSS receiver research. Not only does the work describe the multiple benefits available through a GNSS software radio implementation, but it also establishes the feasibility of such through actual hardware design and experimental results.