Radar Optimal Times Detection Allocation in Multitarget Environment

International audienceThis paper deals with the problem of the management of Electronically Steered Antenna (ESA) in multitarget environments. Radars are used to detect, locate and identify targets. In this paper we focus on the detection of several aerial targets in a fixed given time. The difficulty of such detection lies in the fact that targets may be located anywhere in the space, but radars can only observe a limited part of it at a time. As a result, it is necessary to change their axis position over time. This paper describes the main steps to derive an optimal radar management in this context: the modeling of the radar, the determination of a criterion based on the target detection probability and the temporal optimization process leading to sensor management strategy. An optimization solution is presented for several contexts and several hypotheses about prior knowledge concerning the targets' locations. First, we propose a method for the optimization of the radar detection probability in a single target environment. It consists in the decomposition of the detection step into an optimal number of independent elementary detections. Then, in a multitarget context with deterministic prior knowledge, we present an optimal time allocation method which is based on the results of non linear programming. Finally, in a multitarget context with probabilistic prior knowledge, results in Search Theory are used to determine an optimal temporal allocation

Time Allocation of a Set of Radars in a Multitarget Environment

International audienceThe question tackled here is the time allocation of radars in a multitarget environment. At a given time radars can only observe a limited part of the space; it is therefore necessary to move their axis with respect to time, in order to be able to explore the overall space facing them. Such sensors are used to detect, to locate and to identify targets which are in their surrounding aerial space. In this paper we focus on the detection schema when several targets need to be detected by a set of delocalized radars. This work is based on the modelling of the radar detection performances in terms of probability of detection and on the optimization of a criterion based on detection probabilities. This optimization leads to the derivation of allocation strategies and is made for several contexts and several hypotheses about the targets locations

Nécrologie. Philibert Guinier

Vilmorin Roger de. Nécrologie : Philibert Guinier . In: La Terre et La Vie, Revue d'Histoire naturelle, tome 17, n°3, 1963. pp. 388-389

Compte rendu administratif pour les années 1962 - 1963

Vilmorin Roger de. Compte rendu administratif pour les années 1962-1963 . In: La Terre et La Vie, Revue d'Histoire naturelle, tome 18, n°3, 1964. pp. 241-246

Determination of optimal dynamic management strategies for phased array radars

This work is a contribution to the optimal sensors management problem. The sensors considered in this paper are phased array radars. The authors aim at showing that the modelling of the detection probability of a target with respect to the observation time of that target and the determination of a criterion measuring the quality of the detection in a multitarget environment, allows to derive time managements of the sensor, the performances of which can be analytically or numerically determined. These strategies are derived in a monosensor – monotarget environment and in a monosensor – multitarget environment. The optimal management of the detection function of a sensor being not specific to the radar, this work is a part of a main study which takes aim at determining optimal sensors management for a multisensor system (radar and infrared) in a multitarget environment.Le problème abordé est celui de la gestion dynamique optimale d'un radar à balayage électronique. Notre but est de montrer que la modélisation de la probabilité de détection d'une cible en fonction du temps d'observation de celle-ci, ainsi que l'écriture de critères permettant de quantifier la qualité de détection d'un ensemble de cibles, permet de définir des stratégies de gestion temporelle du capteur. Ces stratégies sont déterminées en environnement monocapteur - monocible et monocapteur - multicible. Nous verrons que les performances de ces stratégies peuvent être déterminées de façon analytique ou numérique. Le problème de la gestion optimale de la fonction de détection d'un capteur n'étant pas spécifique au radar, ce travail s'intègre dans une étude plus large dont le but est de déterminer des stratégies de gestion optimales pour un système multicapteur (radar et infrarouge) en environnement multicible

Sur Les Formes Occidentales Du Pinus Lauicio Poir

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