Directorate of Air Navigation Services

This paper reviews the integrity test methodology for the Global Positioning System (GPS) and the Global Orbiting Navigation Satellite System (GLONASS) receiver autonomous integrity monitoring (RAIM) that has been discussed during GPS/GLONASS MOPS [1] elaboration. For this purpose, we present a multiple hypothesis-based approach to test the integrity performance of the GPS/GLONASS RAIM and the corresponding integrity bound against multiple failures. We compute the prob ability of missed detection (PMD) under each failure, and we compare this PMD to the requirement for single failure (i.e., 10−4), as in lines with the proposed MOPS test method. We also compute total probability of hazardous misleading information (PHMI) by accounting for all possible fault hypothesis and compare it with the integrity risk requirement of 10−7. In a preliminary assessment, it is shown that the maximum PMD for a pair of faults is approximately 10−7 and the maximum PHMI for multiple satellite failures goes up to approximately 210−8 when the proposed method is applied. Also, this paper evaluates the integrity monitoring test procedures outlined by GPS/GLONASS MOPS based on those performance analyses.

In the past, we presented the design process of a visual tool aiming at enhancing the integration of an advanced AMAN (Arrival MANager) in an innovative working environment. This work was indeed the subject of a previous paper. In the context of ATC (Air Traffic Control) working position conception, several options of design have already been explored. Meeting different types of needs, such as providing means to input data efficiently in the system, or means to get relevant information at the right time for a given context at an acceptable cognitive cost may be considered as limitations regarding the type of design. On the other hand, considering solutions that have been retained in other fields may be a source of inspiration for improvements. Sometimes, options that are familiar in a given context may require some efforts to be translated into another. This can be the case for example when considering metro maps style of design. Metro maps can rely on different principles (isometric grid or orthogonal method) but when they are well-designed; they are easy to understand and they enable to navigate with ease (which is their main purpose). Furthermore, their aesthetics play a good part in their comfort of use. Moreover, they are metaphors of a geographical reality that allows to display, with some level of abstraction, but in a quite accurate way, route topography in a constrained space. When considering the design of a new ATC tool that will regroup some information and functionalities that are currently dispatched between several devices, there are some analogies with the above concerns, notably when it comes to the representation of arrival routes and their relations with additional data such as the one linked to Aircraft position and their corresponding AMAN information. The idea is to present a way to apply some of the above principles to the conception of a working position dedicated to the sequencing and coordination task. The point that this paper wants to highlight is that the quality of the design has a direct influence on the way operators use the tools. This can be especially true in the case of critical systems. Furthermore, this is also true when considering the acceptance and the successful operational deployment of innovative functions for which incentive plays an important role. In the first part, the paper will present the sequencing task from an ATCO's (Air Traffic Controller) perspective and present the main features of the supporting tools, notably the AMAN, which is currently in use. It will then highlight some of the current limitations and blocking points. In the second part, the paper will present the user centred design process methodology and the design principles that were applied to produce different design options, some of them having been developed in the form of prototypes, that will be described. In the last part, the paper will describe the definitive design option that lead to the development of a prototype called IODA (Innovative Operations for Departures and Arrivals) and will conclude with some early qualitative assessment results.

This article focuses on branching particle interpretations of rare events. We connect importance sampling techniques with interacting particle algorithms, and multi-splitting branching models. These Monte Carlo methods are illustrated with a variety of examples arising in particle trapping analysis, as well as in ruin type estimation problems. We also provide a rather detailed presentation of the asymptotic theory of these particle algorithms, including exponential extinction probabilities, Lp-mean error bounds, central limit theorem, and fluctuation variance comparaisons.

The delegation to the flight crew of some tasks currently performed by air traffic controllers provides new perspectives to potentially increase air traffic control capacity. The objective of this communication is to provide technical insight into the airborne devices and algorithms which may be used to automatically perform merging and station keeping operations. Indeed, these maneuvers in the field of civil aviation seem difficult to be performed manually and may result in this case in an increase of the flight crew workload. Nevertheless new automated functions onboard aircraft could help to overcome this limitation. This paper investigates the design of a new autopilot mode dedicated to merging and station keeping maneuvers behind a leading aircraft. The proposed relative guidance law considers a 3 -D relative motion, including constant wind and lateral, longitudinal and vertical control. It is based on vectorial backstepping and takes advantage of the skewsymmetric matrix which appears in the relative motion equations. An alternative ‘simplified’ design based on a matrix form of the Young’s inequality is also presented in order to simplify the computation of the guidance law. Then, an illustrative example is discussed and conclusions are raised.