This paper presents a User Range Accuracy (URA)/Signal‐in‐Space Accuracy (SISA) analysis to support ARAIM based on a time‐dependent statistical characterization of orbit and clock error observations. By comparing precise orbits to broadcast ephemeris for each individual GPS and Galileo satellite, this work computes the Signal‐in‐Space Range Error (SISRE) that needs to be overbounded by the URA/SISA value included in the Integrity Support Message (ISM). Service data from January 2008 to February 2015 for GPS and from March to June 2015 for Galileo are processed, showing that range error is mainly driven by satellite's clock performance. In order for the ISM generation to account for the variation in error biases and standard deviation, GPS service history is broken down into monthly, quarterly, and yearly datasets. Results reveal that orbit and clock error distributions are non‐zero mean on a monthly basis, although biases tend to reduce as sample set size increases. Copyright © 2017 Institute of Navigation.

I n t h e 3'd Generation Partnership Project (BGPP) T i m e Division C D M A (TD-CDMA) has been selected as the air interface for the T D D (Time Division Duplexing) bands of 3'd generation (3G) mobile radio systems . In the case of T D D the same channel impulse responses are valid for b o t h the uplink a n d t h e downlink. I n state-of-the-artTD-C D M A characterized b y joint data detection ( J D ) this equality cannot be exploited for enhancing syst e m performance a n d reducing system complexity. In t h e paper a novel TD-CDMA downlink transmission scheme is proposed. This scheme is t e r m e d joint transmission ( J T ) . It utilizes the knowledge of the channel impulse responses gained b y channel estimation at t h e base station in such a way that channel estimators are no longer required at the mobile stations and the computational expense of data detection is dramatically reduced. T h e scheme easily lends itself to t h e utilization of multi-element transmit antennas. Further, its application is not restricted t o systems of t h e t y p e TD-CDMA.

This paper presents the performance analysis of signals from the Galileo satellites in the E1 and E5a frequency bands and GPS L5 signals as measured by DLR's experimental ground-based augmentation system. The results show that the raw noise and multipath level of Galileo signals and of the GPS L5 signals are smaller than that of GPS L1. The new signals are also less sensitive to the choice of carrier-smoothing time constant. Furthermore, the inter-frequency biases that affect dual-frequency processing are investigated. These biases differ between satellites and depend on satellite and receiver hardware, but they can be determined a priori. With known receiver and antenna configurations, it is possible to correct for these biases. A residual uncertainty associated with the bias correction has to be taken into account. This can be modeled as part of the ground and airborne bounding standard deviations (σ pr_gnd and σ pr_air ) used in GBAS processing.

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A key challenge in robotics is the efficient generation of optimal robot motion with safety guarantees in cluttered environments. Recently, deterministic optimal sampling-based motion planners have been shown to achieve good performance towards this end, in particular in terms of planning efficiency, final solution cost, quality guarantees as well as non-probabilistic completeness. Yet their application is still limited to relatively simple systems (i.e., linear, holonomic, Euclidean state spaces). In this work, we extend this technique to the class of symmetric and optimal driftless systems by presenting Dispertio, an offline dispersion optimization technique for computing sampling sets, aware of differential constraints, for samplingbased robot motion planning. We prove that the approach, when combined with PRM*, is deterministically complete and retains asymptotic optimality. Furthermore, in our experiments we show that the proposed deterministic sampling technique outperforms several baselines and alternative methods in terms of planning efficiency and solution cost.

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received the diploma in electrical engineering and the Ph.D. degree from the University of Kaiserslautern, Germany. After graduation, he joined the Research Group for Radio Communications at the Technical University of Kaiserslautern, Germany, as a senior key researcher, where he was involved in various international and national projects in the field of communications and navigation both as project coordinator and as technical contributor. From 2003 till 2013, Dr. Meurer was active as a senior lecturer and Associate Professor (PD) at the same university. Since 2006 Dr. Meurer is with the German Aerospace Centre (DLR), Institute of Communications and Navigation, where he is the director of the Department of Navigation and of the center of excellence for satellite navigation. In addition, since 2013 he is a professor of electrical engineering and director of the Chair of Navigation at the RWTH Aachen University. His current research interests include GNSS signals, GNSS receivers, interference and spoofing mitigation and navigation for safety-critical applications. Dr. Andriy Konovaltsev received his engineer diploma and the Ph.D. degree in electrical engineering from Kharkov State Technical University of Radio Electronics, Ukraine in 1993 and 1996, respectively. He joined the Institute of Communications and Navigation of DLR in 2001. His main research interest is in application of antenna array signal processing for improving performance of satellite navigation systems in challenging signal environments. Manuel Appel received his diploma degree in electrical engineering from the university of applied science Ingolstadt, Germany in 2008. Additionally he received a M.Sc. degree from Technical University Munich in 2013 after working at Fraunhofer Institute for Integrated Circuits in Erlangen. He joined the Institute of Communications and Navigation of DLR in January 2014. His main research interest is in development of signal processing algorithms for robust GNSS receivers with the main focus on spoofing detection and mitigation. Manuel Cuntz received the diploma in electrical engineering degree in 2005 from the Technical University of Kaiserslautern. He joined the Institute of Communications and Navigation of DLR in June 2006. His fields of research are multi-antenna satellite navigation receivers.