Juan Alberto Besada Portas

Opportunity Trajectory Reconstruction Techniques for Evaluation of ATC Systems

This paper describes some key points of a new tool being currently developed by Eurocontrol for the assessment of air traffic control (ATC) multisensor trackers performance. It summarizes the algorithmic foundations of the high-accuracy trajectory reconstruction process used to obtain reference trajectories from recorded measures. These trajectories will serve as a reference for the evaluation of the accuracy of ATC data processing centers. The performance of the system is illustrated with some reconstruction experiments on synthetic and real data.

Application of evolution strategies to the design of tracking filters with a large number of specifications

This paper describes the application of evolution strategies to the design of interacting multiple model (IMM) tracking filters in order to fulfill a large table of performance specifications. These specifications define the desired filter performance in a thorough set of selected test scenarios, for different figures of merit and input conditions, imposing hundreds of performance goals. The design problem is stated as a numeric search in the filter parameters space to attain all specifications or at least minimize, in a compromise, the excess over some specifications as much as possible, applying global optimization techniques coming from evolutionary computation field. Besides, a new methodology is proposed to integrate specifications in a fitness function able to effectively guide the search to suitable solutions. The method has been applied to the design of an IMM tracker for a real-world civil air traffic control application: the accomplishment of specifications defined for the future European ARTAS system.

A model to 4D descent trajectory guidance

Current standard arrival routes or STARs will require in next years more flexibility to handle the increase of aircraft arrivals and to minimize the related environmental impact applying continuous descent trajectories at idle thrust. To do that, a global optimized 4D trajectory must be followed from the given aircraft position to the terminal gate and tracked in real time. 4D trajectory guidance is not an easy task (mainly at arrivals trajectories) due to the variability of the atmospheric and meteorological conditions with the altitude, which introduces discrepancies from the given reference trajectory and the real one. In this paper we present a new 4D trajectory guidance model focussed on the descent and arrival flight phase. This model has been designed as a 4D FMS which is part of an entire dynamic control system using the well established point mass model for the aircraft aerodynamic behaviour. The proposed 4D FMS compares the aircraft state vector with the reference trajectory and calculates the necessary control entrances to fit the actual response to the previously estimated one.

A Multi-Agent Approach for Designing Next Generation of Air Traffic Systems

Current implementation of new technologies for Communication, Navigation, Surveillance and Air Traffic Management (CNS/ATM systems) along with computational improvements on airborne and ground systems developed in the last two decades, point out the need for more strategic navigation and air-traffic control procedures based on four-dimensional (position plus time) trajectories. Moreover, the CNS/ATM infrastructure will help to achieve more shared real-time information among aircraft, airlines and air-traffic services providers (i.e. Air Traffic Control –ATCproviders, meteorological information providers and air space resources information providers). Then, general requirements for a next-generation of Air Traffic Management (ATM) system is that entities must share real-time information about aircraft state and intentions, air-space state and resources, meteorological conditions and forecast, etc. From this information coordinated and strategic actions should be carried out by them in order to achieve efficient and free of conflict 4D trajectories.

A 4D trajectory negotiation protocol for Arrival and Approach sequencing

Future 4D TBO will require effective air- ground data link communication and negotiation protocols. This issue is especially critical in Arrival and Approach flight phase due to the variability of conditions into a short space-time environment where multiple aircraft simultaneously converge. Besides, several subtasks are closely related with effective air-ground negotiation protocols for 4D TBO in Terminal Areas: predicting accurate arrivals 4D trajectories, performing well established 4D trajectory formats for an effective interoperability between airborne and ground systems, designing efficient real-time aircraft arrival sequencer and scheduler algorithms, etc. In this paper we propose a 4D Trajectory Air- Ground Negotiation Protocol for Arrival and Approach Sequencing. The Negotiation Protocol has been implemented in an ad hoc multi-agent platform. Based on this proposal we summarize other relevant information that should be incorporated into the 4D trajectory information.

Airport based bias estimation of surface movement radars

In this proposal, a real time bias estimation system for an airport surveillance data fusion system is presented. This bias estimation system is divided in two main parts. The first part estimates SMR bias terms, taking advantage of the knowledge of the airport map, which is useful because aircraft usually follow the axis of airport taxiways. The other part makes use of SMR corrected measures, which can be assumed to be unbiased. Using them, bias estimators for other important surface surveillance sensors are defined. These estimators are based on processing differences of measurement taken from each sensor and from the SMR. As simulation results show, if the sensor error models are precise enough, both estimations converge to the real bias values, and therefore unbiased measures may be obtained. These unbiased measurements should be provided to the fusion system, in order to enhance tracking performance. These estimation processes do not represent an important computer load increase for the data fusion system. The performance improvement in tracking is also presented.

Design of interacting multiple model filters based on evolution strategies

We present a design procedure, based on ES optimisation, to parametrize IMM tracking structures for air traffic control applications. The objective, not addressed in the available bibliography on IMM filters, is to find the most suitable parameters for a selected IMM structure, accordingly to a determined a set of performance specifications. Two alternative structures are analysed following this procedure, showing the best performance achievable by each one, in terms of the proximity of the performance metrics to the specified values.