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In 1969, a unique set of Late Period bronze casting moulds was discovered at the Qubbet el-Hawa necropolis illustrating the chaîne opératoire of the lost-wax technique. Usually only mould fragments, if anything at all, remain in the archaeological record, but this assemblage presents complete examples representative of different phases of the production of solid-cast bronze artefacts. µCT scans of the moulds have revealed the existence of two entirely different technological approaches. The first is for the regular production of small amulets and statuettes of deities. The second is for attempts at “re-membering” Osiris figures. Previously cast and broken bronze feet are turned into the full form of an Osiris statuette by adding a body modeled in wax, and then placing the combination in a mould to cast a new image of the deity. Technologically, this particular method does not make sense, since a fusion of the newly cast body with the extant metal feet is impossible. This paper proposes a new hypothesis that seeks to explain this casting method in the context of a local ritual use. En 1969, un ensemble unique de moules de l’époque tardive a été découvert dans la nécropole de Qubbet el-Hawa, illustrant la chaîne opératoire de la technique de la cire perdue. Habituellement, il reste au mieux des fragments de moules comme seuls vestiges archéologiques, difficilement identifiables, or ce lot de moules présente des exemplaires complets représentatifs des différentes phases de la production d’artefacts en cire perdue. Les µCT-scans ont révélé l’existence de deux approches technologiques totalement différentes. La première vise à produire de petites amulettes et des statuettes de divinités. La seconde permettrait de tenter des « remembrements » de figures d’Osiris. En effet, des pieds en bronze – préalablement coulés puis cassés – ont été complétés en ajoutant et en y modelant un corps en cire pour donner une forme complète de statuette d’Osiris. Ensuite, cette figure mi-métal, mi-cire, est entourée d’un nouveau moule afin de créer un nouveau corps. D’un point de vue technique, une telle méthode constitue un non-sens, puisqu’une fusion entre le corps nouvellement coulé et les pieds en métal déjà existants n’est pas possible. Dans cet article, une nouvelle hypothèse est proposée, qui pourrait expliquer une telle technique de coulée propre à une utilisation rituelle locale. في عام ١٩٦٩م، تمَّ الكشف في جبانة قبة الهواء عن مجموعة فريدة من قوالب الصبّ البرونزيّة الّتي تعود للعصر المتأخر توضح سلسلة عمليات تقنية الشمع المفقود. عادةً ما يتبقى لنا فقط في السجل الأثريّ أجزاء من قالب (إنْ وُجِدَت) من تقنية الشمع المفقود، لكنَّ هذه المجموعة تُقدِّم لنا أمثلة مُتكاملة عن المراحل المختلفة لعملية تصنيع القطع البرونزيَّة المُصْمَتة. يكشف لنا المسح الضوئي للقوالب باستخدام تقنية التصوير المقطعي المجهري المحوسب (μCT) عن وجود طريقتين تقنيتين مختلفتين تمامًا. كانت أولهما تخص الإنتاج المنتظم للتمائم الصغيرة والتماثيل الصغيرة للمعبودات، أما الطريقة الثانية كانت مُخصَّصة لمحاولات «إعادة تشكيل» تماثيل أوزير، حيث يتمَّ تحويل الأقدام المكسورة إلى الشكل الكامل من تمثال أوزير بإضافة هيكل الجسم المشكَّل من الشمع، ثم وضع هذا المزيج داخل قالب بهدف الوصول إلى الصورة الجديدة من المعبود. لم تعد هذه الطريقة معقولة من الناحية التقنيّة، إذ إنه من المستحيل دمج الجسم المشكَّل حديثًا مع الأقدام المعدنيّة الموجودة من قبل. يقدم لنا هذا البحث فرضية جديدة تسعى إلى تفسير طريقة الصب هذه في سياق استخدام الطقوس المحلية.

Andre Journel joined Stanford University in 1978, and his program grew quickly to include a dozen students from the USA, Canada, Europe, and South Africa. He was instrumental in organizing the Second International Geostatistical Conference (Tahoe ’83), during which 13 papers were presented that can be linked to his group. Out of these 13 papers, 9 were mining-related, with 7 on recoverable reserves, 2 on uncertainty, 2 on conditional simulation, and 3 on nonparametric geostatistics. A significant research effort at the time was therefore directed at change of support, global and local recoveries, and uncertainty, but future trends could also be identified, such as nonparametric geostatistics and conditional simulation. This paper is a practical review of conditional simulation as a tool to improve mineral resource estimation in the areas of uncertainty, classification, and mining selectivity or dilution, based on the authors’ experience. Some practical considerations for conditional simulation are briefly discussed. Four case studies from the early 1990s to the late 2010s are presented to illustrate some solutions and challenges encountered when dealing with real-world commercial projects.

Cremation is a complex mortuary practice, involving a number of activities of the living towards the dead before, during, and after the destruction of the bodily soft tissues by fire. The limiting information concerning these behavioral patterns obtained from the pyre remains and/or cremation deposits prevents the reconstruction of the handling of the corpse during the burning process. This pioneering study tries to determine the initial positioning of the corpse in the pyre and assess whether the deceased was wearing closed leather shoes during cremation through isotopic (δ13C, δ18O) and infrared (ATR-FTIR) analyses of experimentally burnt pig remains, used as a proxy for humans. The results obtained show that both the position of feet on or within the pyre and the presence of footwears may moderately-to-highly influence the oxygen isotope ratios of bone apatite carbonates and the cyanamide content of calcined bone in certain situations. By forming a protective layer, shoes appear to temporarily delay the burning of the underlying pig tissues and to increase the heat-shielding effect of the soft tissues protecting the bone mineral fraction. In such case, bioapatite bone carbonates exchange oxygen with a relatively more 18O-depleted atmosphere (due to the influence of lignin-derived oxygen rather than cellulose-derived oxygen), resulting in more pronounced decrease in the δ18Ocarb values during burning of the shoed feet vs. unshoed feet. The shift observed here was as high as 2.5. A concomitant isotopic effect of the initial location of the feet in the pyres was also observed, resulting in a top-to-bottom decrease difference in the δ18Ocarb values of shoed feet of about 1.4 between each deposition level tested. Finally, the presence of cyanamide (CN/P 0.02) seems to be indicative of closed footwear since the latter creates favorable conditions for its incorporation into bone apatite., SCOPUS: ar.j, info:eu-repo/semantics/published

International audience; This Journal of Archaeological Science: Reports Special Issue was prompted by the organisers of the Second International Conference on Archaeometallurgy (ICA II), which was held at the Lettres Sorbonne Université and École Normale Supérieure de Cachan in Paris, and the Plateforme expérimentale de Melle (CNRS, Institut de Recherche sur les Archéomatériaux) in the Poitou region, France, from the 25th of September to the 1st of October 2019. The conference was made possible thanks to the support of the Lettres Sorbonne Université (ED 1, FIR), CNRS UMR 8167 Orient & Méditerranée (team Mondes pharaoniques) and the MSH Paris-Saclay, and took place within the framework of the Collective Research Program: “L’expérimentation paléométallurgique: de l’analogie à la modélisation” (SRA Nouvelle-Aquitaine, French Ministry of Culture). The conference was organised by Georges Verly, Florian Téreygeol, Claire Somaglino and Frederik Rademakers, further assisted by Johannes Auenmüller, Adeline Bats, Roeland Paardekooper, Jean-Philippe Marnais and Jean-Charles Méaudre.

In this paper, a solution is proposed to answer the problematic issue of the type of fuel used in the early Middle Kingdom smelting furnaces at Ayn Soukhna based on a strict experimental protocol. The protocol was repeated 17 times, for a total of approx. 1500 h of experimental work. In correspondence with the archaeological data obtained at Ayn Soukhna, the combined use of fresh acacia and donkey dung as fuel for smelting is proposed; the use of charcoal for smelting can be excluded. A holistic evaluation of experimental and archaeological evidence has shown that a combination of fresh wood and donkey dung was most likely the standard fuel choice at Middle Kingdom Ayn Soukhna. This is evidenced by the compatibility of results from experimental smelting using wood and donkey dung in terms of furnace lining impact and colorimetry, slag typology and deposition, ash and charcoal distribution, and raw copper shape and size. The use of charcoal systematically results in incompatible smelting results, as does smelting without donkey dung. In addition to green wood, donkey dung is required to regulate the temperature distribution inside the furnaces and to increase the production of copper prills. Green wood creates a favourable atmosphere for the smelting of copper carbonate ore. It heats the lining of the column less, allowing the furnaces to be reused over several campaigns. The dual fuel use of green wood and donkey dung, however, has resulted in the best agreement between experimental smelting results and corresponding archaeological evidence. This archaeometallurgical research in the Nile Valley is carried out by a team composed of Georges Verly, in charge of archaeology and experimental archaeology, and Frederik Rademakers, in charge of archaeometry, as well as numerous master students and a Maitre d’art, Hugues Paridans. Dialogue and interdisciplinarity are the assets of this project, dictating equality between its members, representing the sum of ideas and debates, building all research protocols and publications.

This paper presents the first combined elemental composition and lead isotope (LI) ratio data for Middle Kingdom Egyptian copper alloy artefacts and significantly extends our knowledge on copper smelting remains from the Sinai Peninsula. It further provides the first precise LI ratio and trace element data for two Classic Kerma daggers. Forty-one samples have been analysed from artefacts housed at the Royal Museums of Art and History, Brussels. An important part of this assemblage consists of ore, “slag” and raw metal from workshops associated with 12th Dynasty mining expeditions in the southern Sinai Peninsula. These offer a unique insight into Middle Kingdom copper production chains and the associated waste materials, and form an essential reference group for provenance studies. The other part of the assemblage encompasses finished artefacts from different sites in Egypt—the first ever to be characterised for LI ratios for this period—as well as two daggers from Kerma, Nubia. This study illustrates the need for a careful approach to provenance research of early Egyptian metals, tailored to the particular technologies attested there. Based on the wide range of artefact LI ratios overlapping with those of arsenic-poor Sinai ores on the one hand, and the discrepancy in arsenic content between these ores and artefacts on the other hand, a two-step process for the production of arsenical copper alloys is identified. This suggests some technological continuity with respect to earlier pharaonic periods. The sources for primary copper production, however, likely changed over time: a narrower range of Sinai mines appears to have been exploited compared to preceding periods, and the recycling of circulating metal gained importance in the overall provisioning system.

For a mining operation, minimizing misclassification of ore and waste during grade control is of critical importance. This paper reviews grade control procedures for classifying ore and waste that are based on estimation and conditional simulation approaches. The similarities and differences of the procedures are first discussed in the light of an example. Subsequently, several case studies, including actual operating mines, are presented. The theoretical review shows that conditional simulation is generally better than estimation for ore and waste classification, especially when the profit value of a block is a nonlinear function of the grade of the block. The case studies, however, indicate that, in the context of daily grade control, the value of conditional simulation over good estimation is relatively low compared to the value of improving general practices at mine sites.

Simulation results depend on many parameters such as: modeling assumptions (e.g. Gaussian or Indicator simulation); implementation (e.g. point or block simulation); and case-specific parameters (e.g. top-cut values). The user is often in the dark when it comes to the impact on the results of modeling assumptions and software implementation. Not much literature is available and checks are difficult to complete. This paper is a comparative study of two point and block Gaussian related simulations. The study shows that careful calibration/validation is necessary in both cases to avoid significant biases. Point simulation is easy to validate against primary data because the support does not change; block simulation is more difficult to validate. Both software/algorithms were able to provide what they have been designed for, i.e. conditional simulated values that reproduce the required grade point or block distribution and variogram. Differences, however, were noted between the re-blocked point simulation and direct block simulation results. Differences in application and results of the methods together with advantages and disadvantages are discussed.

The theory of simulation is relatively well documented but not its practice, which is a problem since simulation is not as robust as linear estimation. As a result, many costly mistakes probably go undetected. In this paper, a process for simulation is introduced with the objective of reducing the likelihood of such mistakes. The context is sequential Gaussian simulation within the mining industry. However, a significant part of the process can be applied in other simulation framework. Four of the most important aspects of the process are discussed in detail. A gradual trend adjustment is suggested as a post-simulation step. A modified bootstrap approach is presented to deal with the grade uncertainty that accounts for spatial dependence between the samples. A number of pre- and post-simulation checks are also discussed. Some post-simulation adjustments of the simulated values are suggested to improve on the quality of the simulation. All of the approaches, solutions and checks presented in this paper are simple, flexible, and can be easily implemented by a practitioner.

The linear properties of the multivariate normal distribution make it the most straighforward model for obtaining conditional distributions. Problems of multiple integration have been solved through a Monte-Carlo type approach, thus rendering the multigaussian approach fully operational for the estimation of local reserves and associated spatial distributions.

Variogram.- Improving the Estimation and Modelling of the Variogram.- Towards Resistant Geostatistics.- Statistical Inference of the Semivariogram and the Quadratic Model.- Use of the Jackknife Method to Estimate Autocorrelation Functions (or Variograms).- Computing Variograms in Folded Strata-Controlled Deposits.- The Variogram and Kriging: Robust and Resistant Estimators.- The Variogram and its Estimation.- Inference for Spatial Autocorrelation Functions.- Precision of Global Estimation.- Precision of Estimation of Recoverable Reserves: The Notion of Conditional Estimation Variance.- Estimation Variance of Global Recoverable Reserve Estimates.- Combining Local Kriging Variances for Short-Term Mine Planning.- Application of a Geostatistical Method to Quantitatively Define Various Categories of Resources.- Kriging.- Conditional Bias in Kriging and a Suggested Correction.- Positive Kriging.- Correcting Conditional Bias.- mAD and Conditional Quantile Estimators.- Kriging Seismic Data in Presence of Faults.- Co-Kriging - New Developments.- Indicator Kriging.- The Place of Non-Parametric Geostatistics.- Indicator Kriging as Applied to an Alluvial Gold Deposit.- Estimating Local Recoverable Reserves Via Indicator Kriging.- Conditional Recovery Estimation Through Probability Kriging - Theory and Practice.- Recoverable Reserves.- Recovery Estimation: A Review of Models and Methods.- The Selectivity of the Distributions and "The Second Principle of Geostatistics".- Local Estimation of the Recoverable Reserves: Comparing Various Methods with the Reality on a Porphyry Copper Deposit.- Isofactorial Models and Change of Support.- Geostatistical Application in Tabular Style Lead-Zinc Ore at Pine Point Canada.- Local Estimation of the Block Recovery Functions.- The Block Distribution Given a Point Multivariate Normal Distribution.- Spectral Analysis and Data Analysis.- Three-Dimensional, Frequency-Domain Simulations of Geological Variables.- Factorial Kriging Analysis: A Substitute to Spectral Analysis of Magnetic Data.- The Factorial Kriging Analysis of Regionalized Data. Its Application to Geochemical Prospecting.- The Analysis of Second-Order Stationary Processes: Time Series Analysis, Spectral Analysis, Harmonic Analysis, and Geostatistics.

International audience

International audience

International audience

We present the design, development, and test of three novel, distinct automatic target recognition (ATR) systems for the recognition of airplanes and, more specifically, non-cooperative airplanes, i.e. airplanes that do not provide information when interrogated, in the framework of passive bistatic radar systems. Passive bistatic radar systems use one or more illuminators of opportunity (already present in the field), with frequencies up to 1 GHz for the transmitter part of the systems considered here, and one or more receivers, deployed by the persons managing the system, and not co-located with the transmitters. The sole source of information are the signal scattered on the airplane and the direct-path signal that are collected by the receiver, some basic knowledge about the transmitter, and the geometrical bistatic radar configuration. The three distinct ATR systems that we built respectively use the radar images, the bistatic complex radar cross-section (BS-RCS), and the bistatic radar cross-section (BS-RCS) of the targets. We use data acquired either on scale models of airplanes placed in an anechoic, electromagnetic chamber or on real-size airplanes using a bistatic testbed consisting of a VOR transmitter and a software-defined radio (SDR) receiver, located near Orly airport, France. We describe the radar phenomenology pertinent for the problem at hand, as well as the mathematical underpinnings of the derivation of the bistatic RCS values and of the construction of the radar images.For the classification of the observed targets into pre-defined classes, we use either extremely randomized trees or subspace methods. A key feature of our approach is that we break the recognition problem into a set of sub-problems by decomposing the parameter space, which consists of the frequency, the polarization, the aspect angle, and the bistatic angle, into regions. We build one recognizer for each region. We first validate the extra-trees method on the radar images of the MSTAR dataset, featuring ground vehicles. We then test the method on the images of the airplanes constructed from data acquired in the anechoic chamber, achieving a probability of correct recognition up to 0.99.We test the subspace methods on the BS-CRCS and on the BS-RCS of the airplanes extracted from the data acquired in the anechoic chamber, achieving a probability of correct recognition up to 0.98, with variations according to the frequency band, the polarization, the sector of aspect angle, the sector of bistatic angle, and the number of (Tx,Rx) pairs used. The ATR system deployed in the field gives a probability of correct recognition of 0.82, with variations according to the sector of aspect angle and the sector of bistatic angle.; Dans cette thèse, nous présentons la conception, le développement et le test de trois systèmes de reconnaissance automatique de cibles (ATR) visant à reconnaître des avions non-coopératifs, c’est-à-dire des avions ne fournissant par leur identité, en utilisant des signaux de radars passifs bistatiques. Les radars passifs bistatiques utilisent un ou plusieurs émetteurs d’opportunité (déjà présents sur le terrain), avec des fréquences allant jusqu’à 1 GHz pour les émetteurs considérés ici, et un ou plusieurs récepteurs déployés par le gestionnaire du système et non-colocalisés avec les émetteurs. Les seules informations utilisées sont les signaux réfléchis sur les avions et les signaux directement reçus qui sont tous les deux collectés par le récepteur, quelques informations concernant l’émetteur, et la configuration géométrique du radar bistatique.Les trois systèmes ATR que nous avons construits utilisent respectivement les images radar, les surfaces équivalentes radar (SER) complexes bistatiques et les SER réelles bistatiques. Nous utilisons des données acquises soit sur des modèles d’avions placés en chambre anéchoique à l’ONERA, soit sur des avions réels en utilisant un banc d’essai bistatique consistant en un émetteur VOR et un récepteur basé sur la radio-logicielle (SDR), et que nous avons déployé aux alentours de l’aéroport d’Orly. Nous décrivons d’abord la phénoménologie radar pertinente pour notre problème ainsi que les fondements mathématiques pour la dérivation de la SER bistatique d’un objet, et pour la construction d’images radar d’un objet. Nous utilisons deux méthodes pour la classification de cibles en classes prédéfinies : les arbres extrêmement aléatoires (extra-trees) et les méthodes de sous-espaces. Une caractéristique-clé de notre approche est que nous divisons le problème de reconnaissance global en un ensemble de sous-problèmes par décomposition de l’espace des paramètres (fréquence, polarisation, angle d’aspect et angle bistatique) en régions. Nous construisons un classificateur par région.Nous validons en premier lieu la méthode des extra-trees sur la base de données MSTAR, composée d’images radar de véhicules terrestres. Ensuite, nous testons cette méthode sur des images radar d’avions que nous avons construites à partir des données acquises en chambre anéchoique. Nous obtenons un pourcentage de classification allant jusqu’à 99%. Nous testons ensuite la méthode de sous-espaces sur les SER bistatiques (complexes et réelles) des avions que nous avons extraits des données de chambre anéchoique. Nous obtenons un pourcentage de classification allant jusqu’à 98%, avec des variations suivant la fréquence, la polarisation, l’angle d’aspect, l’angle bistatique et le nombre de paires émetteur-récepteur utilisées. Nous testons enfin la méthode de sous-espaces sur les SER bistatiques (réelles) extraites des signaux acquis par le banc d’essai déployé à Orly. Nous obtenons une probabilité de classification de 82%, avec des variations suivant l’angle d’aspect et l’angle bistatique. On a donc démontré dans cette thèse que l’on peut reconnaitre des cibles aériennes à partir de leur SER acquise en utilisant des signaux de radars passifs bistatiques.

We present the design, development, and test of three novel, distinct automatic target recognition (ATR) systems for the recognition of airplanes and, more specifically, non-cooperative airplanes, i.e. airplanes that do not provide information when interrogated, in the framework of passive bistatic radar systems. Passive bistatic radar systems use one or more illuminators of opportunity (already present in the field), with frequencies up to 1 GHz for the transmitter part of the systems considered here, and one or more receivers, deployed by the persons managing the system, and not co-located with the transmitters. The sole source of information are the signal scattered on the airplane and the direct-path signal that are collected by the receiver, some basic knowledge about the transmitter, and the geometrical bistatic radar configuration. The three distinct ATR systems that we built respectively use the radar images, the bistatic complex radar cross-section (BS-RCS), and the bistatic radar cross-section (BS-RCS) of the targets. We use data acquired either on scale models of airplanes placed in an anechoic, electromagnetic chamber or on real-size airplanes using a bistatic testbed consisting of a VOR transmitter and a software-defined radio (SDR) receiver, located near Orly airport, France. We describe the radar phenomenology pertinent for the problem at hand, as well as the mathematical underpinnings of the derivation of the bistatic RCS values and of the construction of the radar images.For the classification of the observed targets into pre-defined classes, we use either extremely randomized trees or subspace methods. A key feature of our approach is that we break the recognition problem into a set of sub-problems by decomposing the parameter space, which consists of the frequency, the polarization, the aspect angle, and the bistatic angle, into regions. We build one recognizer for each region. We first validate the extra-trees method on the radar images of the MSTAR dataset, featuring ground vehicles. We then test the method on the images of the airplanes constructed from data acquired in the anechoic chamber, achieving a probability of correct recognition up to 0.99.We test the subspace methods on the BS-CRCS and on the BS-RCS of the airplanes extracted from the data acquired in the anechoic chamber, achieving a probability of correct recognition up to 0.98, with variations according to the frequency band, the polarization, the sector of aspect angle, the sector of bistatic angle, and the number of (Tx,Rx) pairs used. The ATR system deployed in the field gives a probability of correct recognition of 0.82, with variations according to the sector of aspect angle and the sector of bistatic angle., Dans cette thèse, nous présentons la conception, le développement et le test de trois systèmes de reconnaissance automatique de cibles (ATR) visant à reconnaître des avions non-coopératifs, c’est-à-dire des avions ne fournissant par leur identité, en utilisant des signaux de radars passifs bistatiques. Les radars passifs bistatiques utilisent un ou plusieurs émetteurs d’opportunité (déjà présents sur le terrain), avec des fréquences allant jusqu’à 1 GHz pour les émetteurs considérés ici, et un ou plusieurs récepteurs déployés par le gestionnaire du système et non-colocalisés avec les émetteurs. Les seules informations utilisées sont les signaux réfléchis sur les avions et les signaux directement reçus qui sont tous les deux collectés par le récepteur, quelques informations concernant l’émetteur, et la configuration géométrique du radar bistatique.Les trois systèmes ATR que nous avons construits utilisent respectivement les images radar, les surfaces équivalentes radar (SER) complexes bistatiques et les SER réelles bistatiques. Nous utilisons des données acquises soit sur des modèles d’avions placés en chambre anéchoique à l’ONERA, soit sur des avions réels en utilisant un banc d’essai bistatique consistant en un émetteur VOR et un récepteur basé sur la radio-logicielle (SDR), et que nous avons déployé aux alentours de l’aéroport d’Orly. Nous décrivons d’abord la phénoménologie radar pertinente pour notre problème ainsi que les fondements mathématiques pour la dérivation de la SER bistatique d’un objet, et pour la construction d’images radar d’un objet. Nous utilisons deux méthodes pour la classification de cibles en classes prédéfinies : les arbres extrêmement aléatoires (extra-trees) et les méthodes de sous-espaces. Une caractéristique-clé de notre approche est que nous divisons le problème de reconnaissance global en un ensemble de sous-problèmes par décomposition de l’espace des paramètres (fréquence, polarisation, angle d’aspect et angle bistatique) en régions. Nous construisons un classificateur par région.Nous validons en premier lieu la méthode des extra-trees sur la base de données MSTAR, composée d’images radar de véhicules terrestres. Ensuite, nous testons cette méthode sur des images radar d’avions que nous avons construites à partir des données acquises en chambre anéchoique. Nous obtenons un pourcentage de classification allant jusqu’à 99%. Nous testons ensuite la méthode de sous-espaces sur les SER bistatiques (complexes et réelles) des avions que nous avons extraits des données de chambre anéchoique. Nous obtenons un pourcentage de classification allant jusqu’à 98%, avec des variations suivant la fréquence, la polarisation, l’angle d’aspect, l’angle bistatique et le nombre de paires émetteur-récepteur utilisées. Nous testons enfin la méthode de sous-espaces sur les SER bistatiques (réelles) extraites des signaux acquis par le banc d’essai déployé à Orly. Nous obtenons une probabilité de classification de 82%, avec des variations suivant l’angle d’aspect et l’angle bistatique. On a donc démontré dans cette thèse que l’on peut reconnaitre des cibles aériennes à partir de leur SER acquise en utilisant des signaux de radars passifs bistatiques.