Papers by Philippe Déliot
HAL (Le Centre pour la Communication Scientifique Directe), May 17, 2018
Impact de la résolution spatiale pour l’identification d’essences forestières en milieu tempéré à... more Impact de la résolution spatiale pour l’identification d’essences forestières en milieu tempéré à partir d’une image hyperspectrale du domaine réflectif. 6. Colloque de la Société Française de Photogrammétrie et Télédétection - Groupe Hyperspectrale (SFPT-GH
In crime scene involving gunshot wound, the experts of forensic science analyze the gunshot resid... more In crime scene involving gunshot wound, the experts of forensic science analyze the gunshot residues to determine the kind of gun used or muzzle-to-target distance. Sometimes these signs are invisible to the naked eye, for example on dark or coloured fabrics. In this perspective, the SYLLABES project has been proposed to design a multispectral laser imaging device that can be set up on crime scene or in laboratory. The first stage before developing this device is to acquire and analyze hyperspectral images. In order to reveal the gunshot residue on fabrics, endmembers extraction methods have been tested. In this paper, two geometrical methods (OSP and N-FINDR) and a statistical one (ICE) are used and compared on fabric samples provided by forensic experts. The potential of endmembers extraction and unmixing methods to enhance residues, either because they can appear as pure components or because they are revealed by the image of reconstruction error, is assessed.
CRC Press eBooks, Jul 15, 2004
Post-Launch Calibration of Satellite Sensors-Morain & Budge (eds) © 2004 Taylor & Francis... more Post-Launch Calibration of Satellite Sensors-Morain & Budge (eds) © 2004 Taylor & Francis Group, London ... 9 £ £ 0.8 Defocus M odei • M easurement O Vertex -28-24-20-16-12-8-4 0 4 8 12 Focusing mechanism position Figure 2. SPOT 5 HRG 1 refocusing (field center-columns ...
ABSTRACT In incidents involving gunshot wounds, for short range target shooting only, gunshot res... more ABSTRACT In incidents involving gunshot wounds, for short range target shooting only, gunshot residues (GSR) are projected on the target and a distinct pattern around the bullet entrance hole may be observed by the forensic experts. A careful analysis of this pattern is often carried out in order to determine the muzzle-to-target distance and angle, and draw some conclusions about the nature of the firearm. However, seeing and recording gunshot residue patterns can be difficult especially if the victim's clothing is dark. The main goal of our study is to develop a multispectral laser imaging device able to reveal gunshot residue patterns on many kinds of clothes, which provide a fast result. The first stage before developing this device is to acquire and analyze hyperspectral images taken on samples in order to select the best spectral bands to use and to develop the appropriate processing to enhance the pattern.
HAL (Le Centre pour la Communication Scientifique Directe), 2013
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Revue Française de Photogrammétrie et de Télédétection
Durant ces dernières décennies, l'imagerie par télédétection aéroportée des milieux urbains r... more Durant ces dernières décennies, l'imagerie par télédétection aéroportée des milieux urbains reste un enjeu scientifique majeur. L'arrivée d'une nouvelle génération de caméras aéroportées permettant d'effectuer des acquisitions à très haute résolution spatiale et possédant un meilleur rapport signal sur bruit ouvre de nouvelles perspectives pour extraire l'information de ces environnements. En effet, la principale limitation de la plupart des méthodes de traitement des images dans ces milieux est due à la grande variété des matériaux qui les compose et à la géométrie dense et complexe qui les caractérise et peut induire de larges zones d'ombre. La campagne (UMBRA) a pour but d'acquérir un nouveau jeu de données de référence représentatif de deux villes françaises distinctes en vue de développer de nouvelles méthodes de correction atmosphérique au soleil et à l'ombre, de concevoir de futures caméras superspectrales dédiées à des applications de télédéte...
HAL (Le Centre pour la Communication Scientifique Directe), Mar 22, 2022
ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2020
In this work, we present the complete workflow used to acquire a large hyperspectral dataset on a... more In this work, we present the complete workflow used to acquire a large hyperspectral dataset on a western Africa historical hydrocarbon production site, and its processing. Our goal is to study how state-of-the-art hyperspectral processing techniques can help detect hydrocarbon bearing soil either of natural origin or accidental by monitoring the health of the vegetation for exploration or environmental monitoring purposes. We present our complete workflow, from acquisition, atmospheric correction, image annotation and classification using modern machine learning techniques, and show how state-of-the-art research can be applied to real-world use cases.
Earth Resources and Environmental Remote Sensing/GIS Applications IX, Oct 9, 2018
Detecting onshore hydrocarbon is a major topic for both environmental monitoring and exploration.... more Detecting onshore hydrocarbon is a major topic for both environmental monitoring and exploration. In this work, a hyperspectral image acquired nearby an old oil extraction site in tropical area is analyzed. The area of interest includes a pit filled with bio-degraded heavy oil, surrounded by herbaceous vegetation and many lagoons. First, we focused on methodologies that can detect oil pollution in an unsupervised manner. Based on the assumption that such oil pits are rare events in the image, statistical approach for anomalies detection, derived from the Reed-Xiaoli detector, is used. In order to decrease the number false alarms, some a priori knowledge about the spectral signature of the pits and about the background is introduced. This approach succeeds in detecting the pit with very few false alarms. Hydrocarbon pollution can have an impact on vegetation and leads to change in vegetation (bio)physical parameters (pigments, water content, …), according to species, pollutant type and exposition time. In order to map the polluted area without any a priori knowledge, several un-supervised classification, including an original method of automatic classification combining unmixing approach and SVM (support Vector Machine) are applied and compared. The results are compared with a partial "ground truth map" that has been derived from visual observations on the field, and with areas of stressed vegetation that have been mapped using combination of specific spectral indices. The classification results are consistent with the ground truth map and the retrieved stressed vegetation areas.
Proceedings of the 2012 International Conference on Quantitative InfraRed Thermography, 2012
We first present a review of the so-called triangle/trapezoid method for soil moisture evaluation... more We first present a review of the so-called triangle/trapezoid method for soil moisture evaluation from optical remote sensing data obtained in the red, near infrared and thermal infrared bands. Recent improvements based on additional vegetation indexes obtained for example from multiwavelength signals in SWIR band will also be presented. In a second part we describe the results we obtained for this purpose by using a microbolometer camera onboard of a motorglider. Signal processing for atmosphere correction and orthorectification was specifically developed for this application. First results on the path for identification of soil water content with this approach will be presented.
For optimal data acquisition and the ability to choose the optical config-uration that closely fi... more For optimal data acquisition and the ability to choose the optical config-uration that closely fits the user's needs, good knowledge of the versatile multi-spectral airborne system being used is required. Airborne remote sensing is a very flexible way to map and moni-tor the land surface. It provides digital image data with very fine spatial resolutions on a precise target area. However, to extract the best information, providers must achieve an optimal opti-cal configuration and a suitable geometric and radiometric cor-rection of the raw data acquired. With the recent development of large visible-spectrum CCDs, snapshot images become feasi-ble with either narrow or large spectral bandwidth. This makes possible many optical configurations to suit a large panel of ex-periments. However, snapshot images need some calibration. To keep the versatility that is the main advantage of airborne sys-tems, rigorous but light calibration is necessary. A technical agreement between Office Na...
2016 8th Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing (WHISPERS)
Soil-hydrocarbon mixtures give complex spectral responses. This has prohibited any physical model... more Soil-hydrocarbon mixtures give complex spectral responses. This has prohibited any physical modelling until now. Spectral analysis and quantification of contamination rate has been performed by regression models, calibrated on spectral databases. Only lab or field databases have been used. This study proposes an innovative joint lab-field-airborne spectral database in the reflective domain (0.4–2.5/xm) to assess the performance of regression models on airborne images of soil-hydrocarbon mixtures. Sample preparation and spectral measurements are described. Implied instruments are an ASD FieldSpec Pro 2 spectrometer and the HySpex hyperspectral camera. Accordance between ground truth and airborne data is shown. Several raw outdoor spectra are displayed.
HAL (Le Centre pour la Communication Scientifique Directe), Sep 19, 2022
Revue Française de Photogrammétrie et de Télédétection
L'ONERA, le laboratoire français en aérospatial, construit des systèmes radar aéroporté depui... more L'ONERA, le laboratoire français en aérospatial, construit des systèmes radar aéroporté depuis plus de deux décennies pour des applications de défense mais aussi scientifiques. Au cours des six dernières années, l'instrument SETHI, embarqué à bord d'un avion Falcon 20, a été développé principalement pour des applications scientifiques. Dans cet article, la philosophie de son développement est mise en exergue et les instruments sont décrits en détails. L'instrument SETHI comprend trois systèmes radar en bandes P, L et X, une caméra dans le domaine visible, en visée oblique afin de suivre le champ de vue des radar, et une caméra hyperspectrale à visée au nadir. Cet article résume alors les dernières campagnes SETHI dans le cas de préparation de deux missions spatiales. Il s'agit tout d'abord de la mission de l'ESA, BIOMASS, comprenant un radar bande P pour la cartographie de la biomasse à grande échelle. La deuxième mission traite de surveillance maritime e...
Sensors, 2022
Water losses from water distribution means have a high environmental impact in terms of natural r... more Water losses from water distribution means have a high environmental impact in terms of natural resource depletion (water, energy, ecosystems). This work aims to develop an optical airborne surveillance service for the detection of water leaks (WADI—Water-tightness Airborne Detection Implementation) to provide water utilities with adequate and timely information on leaks in water transportation mains outside urban areas. Firstly, a series of measurement campaigns were performed with two hyperspectral cameras and a thermal infrared camera in order to select the most appropriate wavelengths and combinations thereof for best revealing high moisture areas, which are taken as a proxy for water leakage. The Temperature-Vegetation-Index method (T-VI, also known as Triangle/Trapezoid method) was found to provide the highest contrast-to-noise ratio. This preliminary work helped select the most appropriate onboard instrumentation for two types of aerial platforms, manned (MAV) and unmanned (U...
Remote Sensing, 2021
With an increase in the overseas maritime transport of hazardous and noxious substances (HNSs), H... more With an increase in the overseas maritime transport of hazardous and noxious substances (HNSs), HNS-related spill accidents are on the rise. Thus, there is a need to completely understand the physical and chemical properties of HNSs. This can be achieved through establishing a library of spectral characteristics with respect to wavelengths from visible and near-infrared (VNIR) bands to shortwave infrared (SWIR) wavelengths. In this study, a ground HNS measurement experiment was conducted for artificially spilled HNS by using two hyperspectral cameras at VNIR and SWIR wavelengths. Representative HNSs such as styrene and toluene were spilled into an outdoor pool and their spectral characteristics were obtained. The relative ratio of HNS to seawater decreased and increased at 550 nm and showed different constant ratios at the SWIR wavelength. Noise removal and dimensional compression procedures were conducted by applying principal component analysis on HNS hyperspectral images. Pure HN...
IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium, 2018
In this paper we focus on airborne hyperspectral imaging methodology to characterize PM (Particul... more In this paper we focus on airborne hyperspectral imaging methodology to characterize PM (Particulate Matter) size near industrial plume emission source. Two intensive campaigns were conducted in the vicinity of a refinery in the south of France, in September 2015 and February 2016. During the campaigns different observation protocols of PM were deployed. A multi temporal methodology to retrieve aerosol type, to map the aerosol concentration and to quantify mass flow rate from airborne hyperspectral data is described in this paper. This method applied to the refinery main stack give a black carbon ratio around 10% and aerosol size mode less than 100 nm with a metric spatial resolution. These results show a good agreement with in-situ measurements and flow rate modelling.
IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium, 2018
Mineralogical clays are intimately mixed in soils. Until now, there is not a clear view on which ... more Mineralogical clays are intimately mixed in soils. Until now, there is not a clear view on which unmixing methods are the most effective in case of intimate mixtures with both clays and with other mineral. A laboratory approach is proposed in order to compare existing linear and nonlinear unmixing approaches in terms of performances. Laboratory images of pure clays of Montmorillonite, Illite and Kaolinite were preprocessed using 6 transformations commonly used in literature (SNV, CR, CWT, Hapke, 1st SGD, Log(l/R)). Prediction of abundances has been performed on non-preprocessed and preprocessed data with 2 linear unmixing methods (FCLS and MESMA) and 2 nonlinear unmixing methods (GBM and MLM). Results show a decrease of unmixing performance due to sample variability, which can be reduced using the appropriate preprocessing. However, no particular advantage has been found on using nonlinear over linear unmixing approaches for clay minerals.
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Papers by Philippe Déliot