Required navigation performance

About: Required navigation performance is a research topic. Over the lifetime, 343 publications have been published within this topic receiving 3477 citations. The topic is also known as: RNP.

Placing LDACS-based ranging sources for robust RNP 1.0 accuracy en-route

Abstract: Global Navigation Satellite Systems (GNSS) are becoming the primary means of navigation for civil aviation. Nevertheless, concerns about GNSS outages remain, driving the need for Alternative Positioning, Navigation and Timing (APNT) systems to provide availability and continuity for performance-based navigation services. Although the existing Distance Measuring Equipment (DME) infrastructure is able to provide Required Navigation Performance (RNP) 1.0 accuracy, it is not robust for individual station outages. Additionally, we show that in the European airspace DME is reaching the capacity limit. To address these two problems, we propose a methodology based on modular APNT. In the presented approach, the complementary ranging sources are optimally placed to obtain robustness. It is assumed that the L-Band Digital Aeronautical Communications System (LDACS) can provide this capability. As shown in the results, the modular APNT system is able to provide robust RNP 1.0 coverage for Germany using 17 new LDACS ground stations to complement the network of 73 existing DME installations in Germany.

Algorithm and configuration availability tool for integrity monitoring test bed

Abstract: This paper describes an availability analysis tool that is developed to simulate a ground-based augmentation system (GBAS) prototype as an integrity monitoring test-bed (IMT) at an airport of interest. This simulation tool includes the IMT master station algorithm, reference station algorithm, reference station siting configurations, and IMT user algorithm. In addition, a user-friendly graphical user interface is developed to allow the user to modify the parameters of the algorithms, the IMT reference station network, user locations, and satellite constellations. The output of the tool is the Stanford Chart, which indicates the availability for the user protection level calculation versus various required navigation performance levels, such as Category I landing. The simulation tool is implemented in Qt (http://qt.digia.com/), an open-source cross-platform toolkit, allowing the tool to run on various devices. Several airports in different flight information regions are used as examples to demonstrate the utility of the proposed IMT algorithm and the configuration availability simulation tool by analyzing their GBAS service volumes. Cases with reduced error models are also simulated in this paper. This study develops a fast, accurate, and highly customizable GBAS availability simulation tool for GBAS algorithms and configuration planning at the airport of interest.

GNSS/Electronic Compass/Road Segment Information Fusion for Vehicle-to-Vehicle Collision Avoidance Application

Abstract: The increasing number of vehicles in modern cities brings the problem of increasing crashes. One of the applications or services of Intelligent Transportation Systems (ITS) conceived to improve safety and reduce congestion is collision avoidance. This safety critical application requires sub-meter level vehicle state estimation accuracy with very high integrity, continuity and availability, to detect an impending collision and issue a warning or intervene in the case that the warning is not heeded. Because of the challenging city environment, to date there is no approved method capable of delivering this high level of performance in vehicle state estimation. In particular, the current Global Navigation Satellite System (GNSS) based collision avoidance systems have the major limitation that the real-time accuracy of dynamic state estimation deteriorates during abrupt acceleration and deceleration situations, compromising the integrity of collision avoidance. Therefore, to provide the Required Navigation Performance (RNP) for collision avoidance, this paper proposes a novel Particle Filter (PF) based model for the integration or fusion of real-time kinematic (RTK) GNSS position solutions with electronic compass and road segment data used in conjunction with an Autoregressive (AR) motion model. The real-time vehicle state estimates are used together with distance based collision avoidance algorithms to predict potential collisions. The algorithms are tested by simulation and in the field representing a low density urban environment. The results show that the proposed algorithm meets the horizontal positioning accuracy requirement for collision avoidance and is superior to positioning accuracy of GNSS only, traditional Constant Velocity (CV) and Constant Acceleration (CA) based motion models, with a significant improvement in the prediction accuracy of potential collision.

Integrated GNSS/DR/road segment information system for variable road user charging

Abstract: Road User Charging (RUC) is designed to reduce congestion and collect revenue for the maintenance of transportation infrastructure. In order to determine the charges, it is important that appropriate Road User Charging Indicators (RUCI) are defined. This paper focusses on Variable Road User Charging (VRUC) as the more dynamic and flexible compared to Fixed Road User Charging (FRUC), and thus is a better reflection of the utility of the road space. The main issues associated with VRUC are the definition of appropriate charging indicators and their measurement. This paper addresses the former by proposing a number of new charging indicators, considering the equalization of the charges and marginal social cost imposed on others. The measurement of the indicators is addressed by a novel data fusion algorithm for the determination of the vehicle state based on the integration of Global Navigation Satellite Systems (GNSS) with Dead Reckoning (DR) and road segment information. Statistical analyses are presented in terms of the Required Navigation Performance (RNP) parameters of accuracy, integrity, continuity and availability, based on simulation and field tests. It is shown that the proposed fusion model is superior to positioning with GPS only, and GPS plus GLONASS, in terms of all the RNP parameters with a significant improvement in availability.

Measuring the effects of RNAV departure procedures on airport efficiency

Abstract: To analyze the impact of area navigation-standard instrument departure (RNAV SID) on operations at Atlanta terminal radar approach control (ATL TRACON). The MITRE Corporation's Center for Advanced Aviation System Development (CAASD) collected radar track data prior to implementation of the RNAV procedures, as well as post-implementation data. Through analysis of this radar track data, we measure the effects of RNAV SID procedures on departure throughput, and the resulting effects on taxi-out time and departure delay. In addition, distance flown inside the terminal area is a key metric. Vertical performance inside the terminal area was analyzed for reductions in level-offs. Results are coordinated and validated with anecdotal data from the airlines regarding these benefits and others, and statistical analyses combined with operational feedback provides insight towards the benefits of these procedures.