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.

Support infrastructures based on high altitude platforms for navigation satellite systems

Abstract: In this article the use of an augmentation system based on high altitude platforms (HAPs) for supporting global navigation satellite systems is discussed. In fact, HAP-based systems are being studied and designed for several communication applications, but they can also be considered added value infrastructure if integrated with navigation systems, providing aiding services based on terrestrial stations or geostationary satellites. The article investigates the results of a feasibility study for the design of a stratospheric pseudo-satellite to provide additional ranging signal to improve the accuracy and availability of the overall navigation system, and an effective integrity service, strengthening the reliability of the positioning procedures. The work here presented discusses issues that have arisen in the design, and provides simulation performance of the proposed architecture.

Characterization of Nominal Signal Distortions and Impact on Receiver Performance for GPS (IIF) L1/L5 and Galileo (IOV) E1 /E5a Signals

Abstract: Modeling both nominal distortions and signal anomalies (i.e. Evil waveforms, International Civil Aviation Organization (ICAO) threat models) is crucial for an accurate user error budget for Space-based Augmentation Systems (SBAS) and Ground-based Augmentation systems (GBAS) (multi-frequency, multi-constellation). Such analysis is of particular interest for the ongoing standardization work of L1-L5 SBAS services. In this paper we propose a method to jointly estimate the analog and the digital distortions. This comes very useful in those cases in which the estimates of the two satellite imperfections are interdependent, e.g. when the time-bandwidth product is small. The impact of both satellite imperfections on the ranging performance of a Global Navigation Satellite Systems (GNSS) receiver is assessed by means of analytical formulas which make use of the cross-power spectral density (CPS) between the distorted and the ideal signal, and of the power spectral density (PSD) of the nominal (ideal) signal.

Probability of detection for GNSS signals with sign transitions

Abstract: In global navigation satellite system (GNSS) receivers, the acquisition process is the first stage of the signal processing module. It consists of assessing the presence of GNSS signals and providing a rough estimation of the incoming signal parameters: the Doppler frequency and the code delay. However, the presence of bit sign transitions affects receiver performance in signal acquisition detection. This article focuses on the bit transition and its impact on the acquisition performance by providing a general mathematical study and an illustration for two GNSS signals: the global positioning system legacy civil signal (GPS L1 C/A) and Galileo E1 open service (OS). This study is applicable to a terrestrial user in a constraint environment. Furthermore, the presented results are mathematical models of the probability of detection in the presence of bit sign transitions (only one potential bit sign transition per integration interval), and potential uncertainties on the Doppler frequency and code delay. These do not result from empirical acquisition of real signals.

Space based augmentation system with hierarchy for determining geographical corrections source

Abstract: Systems, devices and methods are provided for determining the appropriate or desired geographical correction source for SBAS corrections. One aspect provided herein is a method. According to one method embodiment, a Space Based Augmentation System (SBAS) correction message is received from a selected SBAS satellite. It is determined whether at least one criterion is satisfied for using the selected SBAS satellite as a correction source and then processing the correction message received therefrom. A second SBAS satellite is selected from which to receive SBAS correction messages upon determining that at least one criterion is not satisfied for using the selected SBAS satellite as a correction source. One example of SBAS is the Wide Area Augmentation System (WAAS) used in North America. Other aspects and embodiments are provided herein.

The role of Global Navigation Satellite System (GNSS) software radios in embedded systems

Abstract: This paper outlines the motivation for Global Navigation Satellite System (GNSS) software receivers. Features of traditional and software-based GNSS receiver architectures are highlighted and compared, focusing on the advantages of the software design. The choice of which architecture is advantageous, particular in the case of embedded systems, is present along with design criteria—both for the current environment as well as what can be expected in the future.