Pour des systèmes électromagnétiques, comme le radar, il est important de modéliser précisément la propagation sur de longues distances en tenant compte des effets de l'environnement. Une méthode répandue dans ce contexte est basée sur la résolution de l'équation parabolique par split-step Fourier (SSF). Cependant, pour des scénarios 3D elle est limitée par son temps de calcul et sa taille mémoire. Récemment, une méthode efficace en temps et mémoire en ondelettes a été proposée en 2D. Dans cet article, nous généralisons la méthode à des scénarios 3D. Nous montrons également qu'elle est de complexité plus faible que SSF. Des tests numériques sont également proposés pour...

Over the past few years, Mobility-as-a-Service (MaaS) has become an alternative to owning a private car, integrating various public and shared travel modes in a single platform. Despite its attractiveness in meeting everyday travel needs, it has not seen high penetration rates within the urban population. A solution to increase its acceptability is to improve its personalisation so that it can better cater to the needs of each user. In this paper, we propose the global architecture of a MaaS tool under development for the city of Toulouse and its surroundings. The proposed architecture combines the information about users' mobility patterns and their individual...

According to the long term air traffic forecasts done by International Civil Aviation Organization (ICAO) in 2018, global passenger traffic is expected to grow by 4.2% annually from 2018 to 2038 using the traffic data of 2018 as a baseline. Even though the outbreak of COVID-19 has caused a huge impact on the air transportation, it is gradually restoring. Considering the potential demand in future, air traffic efficiency and safety will remain critical issues to be considered. In the airspace system, the runway is the main bottleneck in the aviation chain. Moreover, in the domain of air traffic management, the Terminal Maneuvering Area (TMA) is one of the most complex...

Disruptions on airport access mode impact the passenger journey. This paper shows that the impact can be mitigated with a modest tactical rescheduling of flights. Operational constraints related to connecting flights, minimum turnaround time, runway throughput limitations, terminal and taxi network capacities are considered. In order to solve this optimization problem, we implement a simulated annealing coupled with a simulation-based evaluation and a sliding time window. We propose a data-driven approach to simulate the passenger arrival process at the airport. The coordination mechanism has been evaluated on several scenarios with different levels of disruption. New...

With the growing number of flights, more and more conflicts have to be solved in Terminal Manoeuvring Areas (TMAs). In order to keep a fluid flow of aircraft arriving on an airport, air traffic controllers use softwares to help them to solve conflicts and sequence aircraft on runways. This paper faces the sequencing and merging problem using a reinforcement learning algorithm (Q-Learning) in order to measure its performance. This algorithm has been run on a scenario representing a regular day at Paris Charles de Gaulle airport (CDG), and gives satisfying results. Then, it has been benchmarked on heavilyloaded scenarios, with more aircraft than the previous ones in order...

Improving short-term air traffic flow prediction can help forecast demand and maximize existing capacity by tactical air traffic flow management. Most existing studies in flow prediction lacks consideration of the dynamic, structural, and interrelated nature of air traffic flows in the airspace. Therefore, this paper proposes to predict sector entry flows based on graph convolutional networks, which consider the dynamic spatial-temporal features of air traffic from a graph perspective. First, we specify a sector entry flow based on its upstream and downstream sectors. Then, each entry flow is denoted as a node in a graph. The weighted edges between the nodes are learned...

The rapid growth of the metropolis leads to the proposal of alternative solutions, including the concept of Urban Air Mobility (UAM). Automated and highly-integrated UAM networks have been proved to have great advantages to handle UAM traffic flow with intense density and complexity in the near future. This research addresses designing UAM route networks in low-altitude airspace to minimize noise impact and maximize the efficiency and safety of UAM operations. Singapore's urban airspace is selected for the case study. On the basis of the open-source data of Singapore, the UAM network is designed as a grid-based multi-layer route network that supports twoway traffic. The...

Airspace capacity has become a critical resource for air transportation. Complexity in traffic patterns is a structural problem, whereby airspace capacity is sometimes saturated before the number of aircraft has reached the capacity threshold. This paper addresses a strategic planning problem with an efficient optimization approach that minimizes traffic complexity based on linear dynamical systems in order to improve the traffic structure. Traffic structuring techniques comprise departure time adjustment, en route trajectory deviation, and flight-level allocation. The resolution approach relies on the hyperheuristic framework based on reinforcement learning to improve...

Aircrafts are increasingly equipped with in-flight connectivity systems, giving access to broadband communications for passengers. This paper studies whether it may be possible to use these public air-ground networks to also support aircraft safety-related aeronautical communications in the future. The benefits and other justifications are also examined, including the challenges and potential 'showstoppers'. It provides a risk and a SWOT analysis and introduces potentially suitable technical mechanisms.