Embedded Ready To Use Hybrid Mesh Network For IoT Applications

Gathering data from IoT (Internet of Things) sensors requires a communication infrastructure. This infrastructure could rely on WiFi, LAN or other proprietary networks as well as on mesh networks using any kind of radio technology. Thus, these networks are a prerequisite to conveys this data. In addition, some IoT applications such as asset or human tracking requires a dedicated network of sensors as well. That means that the overall solution requires device provisioning, configuration, installation and maintenance, as well as devices and network planning, leading to huge cost due to manual installation, ad-hoc configuration and maintenance operations. This solution aims at removing all the drawbacks of the current solutions by limiting as much as possible the manual operations

Estimation et modélisation de la distribution spatiale de l'eau au sein d'un couvert végétal (mise en oeuvre d'un dispositif multipôle fonctionnant en régime quasi-statique)

VERSAILLES-BU Sciences et IUT (786462101) / SudocSudocFranceF

HYEMALIS: Un Simulateur d'Images de Paysages Tridimensionnels Complexes

National audienceThis paper deals with HYEMALIS, a software developed by NOVELTIS in collaboration with INRIA to simulate complex three-dimensional landscapes and remote sensing images in the solar spectrum. HYEMALIS is composed of several modules : radiative transfer computation with a radiosity algorithm, atmospheric interaction model coupling, airborne or space borne sensor simulation. This software can be used to lead various applications relating to urban landscape observation like helping in mission design, testing image processing algorithms, simulating directional reflectance databases.Cet article présente HYEMALIS, un atelier logiciel développé par NOVELTIS en collaboration avec l'INRIA permettant de simuler des paysages tridimensionnels complexes et des images de télédétection dans le domaine spectral solaire. HYEMALIS est composé de plusieurs modules : calcul du transfert radiatif par un algorithme de radiosité, couplage avec un modèle d'interaction atmosphérique, simulation du capteur aéroporté ou orbital. Cet outil permet de conduire de nombreuses applications en relation avec l'observation des milieux urbains : aide à la définition de missions, test d'algorithmes de traitement d'images, simulation de bases de données de réflectances directionnelles

Estimation of the vertical profile of the wheat crop water content with an electrostatic multipole. An experimental study

A new instrument, an electrostatic multipole, has been developed to assess in situ and non-destructive estimations of water content of horizontal layers of crops by dielectric measurements. A winter wheat crop was measured by using the multipole during the last month before harvesting. Results show that it is possible to detect the plant development stages, typically the end of the water plateau revealing the grain maturity. The electrostatic multipole was also used to estimate the total water content of the canopy aerial part. The average error on the water content is about 320 g$\cdot$m$^{-2}$. Simultaneous estimations of spike and stem water contents can also be achieved; the root mean square errors (RMSE) are about 120 g$\cdot$m$^{-2}$ and 230 g$\cdot$m$^{-2}$ respectively. However the accuracy of these estimations decreases as the plant water content becomes spatially heterogeneous. On relatively homogeneous plots the RMSE of the spike and stem water contents are respectively 100 g$\cdot$m$^{-2}$ and 195 g$\cdot$m$^{-2}$. These values correspond to a relative error of about 15% which is very close to the accuracy of the gravimetric technique considered as the reference method.Estimation in situ du profil vertical du contenu en eau d'une culture de blé à l'aide d'un multipôle électrostatique. Étude expérimentale. Un nouvel instrument de mesure, un multipôle électrostatique, a été développé pour permettre l'estimation in situ et non destructive du contenu en eau des strates horizontales d'un couvert végétal grâce à la mesure de leur permittivité diélectrique. Une culture de blé d'hiver a été suivie à l'aide de ce multipôle électrostatique pendant un mois jusqu'à la récolte. Les résultats montrent qu'il est possible de détecter les stades de développement des plantes, notamment la fin du palier hydrique révélatrice de la maturité des grains. Le multipôle électrostatique a également été utilisé pour estimer le contenu en eau des plantes. L'erreur moyenne commise sur le contenu en eau est de l'ordre de 320 g$\cdot$m$^{-2}$. Les contenus en eau des épis et des tiges de blé peuvent par ailleurs être estimés simultanément avec une précision d'environ 120 g$\cdot$m$^{-2}$ pour les épis et 230 g$\cdot$m$^{-2}$ pour les tiges. Cependant, cette précision est limitée en présence de fortes hétérogénéités de contenu en eau. En évitant ces fortes hétérogénéités, les contenus en eau des épis et des tiges peuvent être estimés avec une meilleure précision, respectivement de l'ordre de 100 g$\cdot$m$^{-2}$ et de 195 g$\cdot$m$^{-2}$. Ces valeurs correspondent respectivement à des précisions relatives de l'ordre de 15 % , précisions comparables à celle de la méthode pondérale de référence

ALANIS: a joint ESA–iLEAPS atmosphere–land interaction study over boreal Eurasia

Determining the role of the Eurasian boreal region is essential in understanding the global Earth system as it represents the largest terrestrial ecosystem on the planet. The size and remoteness of boreal Eurasia, however, pose a challenge to quantification of both terrestrial ecosystem processes and their feedbacks to regional and global climate. In the last few years, Earth Observation (EO) data have demonstrated the potential to become a major tool for estimating key variables and characterizing main processes governing the land-atmosphere interface over the extremely wide and often unreachable northern areas of boreal Eurasia. The European space Agency (ESA) in collaboration with iLEAPS has launched the ALANIS project (Atmosphere-LANd Interaction Study) to advance towards the development and validation of novel EO-based multi-mission products and their integration into suitable land-atmosphere coupled models. One of the three ALANIS projects (ALANIS – methane), led by the Centre for Ecology and Hydrology, aims to reduce current uncertainties in methane emissions from boreal wetlands through the synergic use of land and atmosphere EO-based products characterising boreal lake and wetland dynamics as well as atmospheric methane concentrations in coupled land-atmosphere models. This article presents an overview of the ALANIS initiative and the three projects

Complémentarité des images Pléiades et drone pour la viticulture de précision dans le cadre du programme EarthLab

National audienceThe potentiality of the Pléiades product has been assessed in the framework of the EarthLab programme set up by Telespazio France. « EarthLab Vine » aims at providing vineyard owners and wine sector with various products and services dedicated to accurate and regular monitoring of vineyards in order to improve the technical management and increase the value of the production. Telespazio France has based the EarthLab products on the different very high resolution acquisition techniques available nowadays: satellite, aerial and UAV (Unmanned Aerial Vehicle). Thanks to its resolution in the panchromatic mode, the Pléiades sensor provides images at a resolution that is compatible with the resolution required for precision agriculture activity especially viticulture where the order of magnitude of the vine elements (rows) is about 1 metre. The multispectral information is brought through a pans harpening method so as to get the information at the highest possible resolution. This step is necessary to highlight the various elements of the target scene especially the rows and inter-rows that are not distinguishable on the native resolution images (2 metres). Then the pansharpened images are processed in order to generate various products especially a vegetation index map, vegetation index maps for the rows and for the inter-rows, as well as a map showing missing or dead vine stocks. This study has shown on some vineyard plots that results obtained from the Pléiades images are spatially consistent with the results obtained from very high resolution images acquired by an UAV. Consequently, the same products can be derived from both image sets: vigour maps, row detection, missing or dead stocks. However, small detail detection such as missing or dead stocks is more difficult on the Pléiades images than on the UAV images. On vineyards with narrow rows, Pléiades pixels are very often mixed pixels composed of inter-row vegetation (grass) and vine components, which highlights the limit of the sensor resolution compared to the UAV image resolution. Consequently, UAV imagery is still more adapted in some spatial configurations. This study has shown the potentiality of Pléiades for precision viticulture applications thanks to their high resolution compared to SPOT satellite family, as well as the synergy with very high resolution imagery (UAV or aerial acquisitions). Beyond the very high resolution capabilities of Pléiades, the spatial coverage as well as the short revisit time are of high interest compared to the constraints of the aerial techniques

Ground-based GPS imaging of ionospheric post-seismic signal

International audienceDuring the Demeter mission, a continuous global positioning system (GPS) ionospheric tomography above Europe, Japan and California will be performed with the Service and Products of ionosphere Electronic Content and Tropospheric Refractive index over Europe (SPECTRE) experiment. The main goal of the conducted observations is to detect and characterize post-seimic ionospheric perturbations associated to seismic generated waves, more precisely near field seismic waves, far field Rayleigh waves and tsunamis. We first review the theory describing post-seismic ionospheric signals as well as the most recent observations of these signals. We then present the description of the tomographic procedure used for the SPECTRE experiment, as well as the obtained tomographic models. We finally draw the perspective of such observations

High Risk of Anal and Rectal Cancer in Patients With Anal and/or Perianal Crohn’s Disease

International audienceBackground & AimsLittle is known about the magnitude of the risk of anal and rectal cancer in patients with anal and/or perineal Crohn’s disease. We aimed to assess the risk of anal and rectal cancer in patients with Crohn’s perianal disease followed up in the Cancers Et Surrisque Associé aux Maladies Inflammatoires Intestinales En France (CESAME) cohort.MethodsWe collected data from 19,486 patients with inflammatory bowel disease (IBD) enrolled in the observational CESAME study in France, from May 2004 through June 2005; 14.9% of participants had past or current anal and/or perianal Crohn’s disease. Subjects were followed up for a median time of 35 months (interquartile range, 29–40 mo). To identify risk factors for anal cancer in the total CESAME population, we performed a case-control study in which participants were matched for age and sex.ResultsAmong the total IBD population, 8 patients developed anal cancer and 14 patients developed rectal cancer. In the subgroup of 2911 patients with past or current anal and/or perianal Crohn’s lesions at cohort entry, 2 developed anal squamous-cell carcinoma, 3 developed perianal fistula–related adenocarcinoma, and 6 developed rectal cancer. The corresponding incidence rates were 0.26 per 1000 patient-years for anal squamous-cell carcinoma, 0.38 per 1000 patient-years for perianal fistula–related adenocarcinoma, and 0.77 per 1000 patient-years for rectal cancer. Among the 16,575 patients with ulcerative colitis or Crohn’s disease without anal or perianal lesions, the incidence rate of anal cancer was 0.08 per 1000 patient-years and of rectal cancer was 0.21 per 1000 patient-years. Among factors tested by univariate conditional regression (IBD subtype, disease duration, exposure to immune-suppressive therapy, presence of past or current anal and/or perianal lesions), the presence of past or current anal and/or perianal lesions at cohort entry was the only factor significantly associated with development of anal cancer (odds ratio, 11.2; 95% CI, 1.18-551.51; P = .03).ConclusionsIn an analysis of data from the CESAME cohort in France, patients with anal and/or perianal Crohn’s disease have a high risk of anal cancer, including perianal fistula–related cancer, and a high risk of rectal cancer