Learning Speckle Suppression in Sar Images Without Ground Truth: Application to Sentinel-1 Time-Series

International audienceThis paper proposes a method of denoising SAR images, using a deep learning method, which takes advantage of the abundance of data to learn on large stacks of images of the same scene. The approach is based on the use of convolu-tional networks, used as auto-encoders. Learning is led on a large pile of images acquired on the same area, and assumes that the images of this stack differ only by the speckle noise. Several pairs of images are chosen randomly in the stack, and the network tries to predict the slave image from the master image. In this prediction, the network can not predict the noise because of its random nature. Also the application of this network to a new image fulfills the speckle filtering function. Results are given on Sentinel 1 images. They show that this approach is qualitatively competitive with literature

Interdisciplinary assessment of sea-level rise and climate change impacts on the lower Nile delta, Egypt

Copyright © 2015 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Science of the Total Environment. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Science of the Total Environment Vol. 503-504 (2015), DOI: 10.1016/j.scitotenv.2014.06.111CLImate-induced changes on WAter and SECurity (CLIWASEC) was a cluster of three complementary EC-FP7 projects assessing climate-change impacts throughout the Mediterranean on: hydrological cycles (CLIMB - CLimate-Induced changes on the hydrology of Mediterranean Basins); water security (WASSERMed - Water Availability and Security in Southern EuRope and the Mediterranean) and human security connected with possible hydro-climatic conflicts (CLICO - CLImate change hydro-COnflicts and human security). The Nile delta case study was common between the projects. CLIWASEC created an integrated forum for modelling and monitoring to understand potential impacts across sectors. This paper summarises key results from an integrated assessment of potential challenges to water-related security issues, focusing on expected sea-level rise impacts by the middle of the century. We use this common focus to illustrate the added value of project clustering. CLIWASEC pursued multidisciplinary research by adopting a single research objective: sea-level rise related water security threats, resulting in a more holistic view of problems and potential solutions. In fragmenting research, policy-makers can fail to understand how multiple issues can materialize from one driver. By combining efforts, an integrated assessment of water security threats in the lower Nile is formulated, offering policy-makers a clearer picture of inter-related issues to society and environment. The main issues identified by each project (land subsidence, saline intrusion - CLIMB; water supply overexploitation, land loss - WASSERMed; employment and housing security - CLICO), are in fact related. Water overexploitation is exacerbating land subsidence and saline intrusion, impacting on employment and placing additional pressure on remaining agricultural land and the underdeveloped housing market. All these have wider implications for regional development. This richer understanding could be critical in making better policy decisions when attempting to mitigate climate and social change impacts. The CLIWASEC clustering offers an encouraging path for the new European Commission Horizon 2020 programme to follow.European Commission Seventh Framework Program CLICOEuropean Commission Seventh Framework Program CLIMBEuropean Commission Seventh Framework Program WASSERMe

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Change detection in SAR time-series based on the coefficient of variation

This paper discusses of change detection in SAR time-series. Several criteria based on the temporal coefficient of variation are proposed, dedicated to different kind of changes. Firstly, the coefficient of variation is used alone to detect any changes; some statistical properties highlights its pertinence. Secondly, two other criteria based on ratios of coefficients of variations are proposed to detect long events such as construction test sites or point-event such as vehicles. These detection methods are evaluated both on theoretical statistical simulation and on real data for different types of scenes and sensors (Sentinel-1, TerraSAR-X, UAVSAR). In particular, a quantitative evaluation is performed with a comparison of our solutions with a reference one

Urban change detection by comparing SAR images at different resolution and polarimetric modes

International audience<p>Today, the variety of remote sensing satellites increases the interest of combining images of different types to satisfy the needs of earth monitoring with a better reactivity. In this context, this article aims to demonstrate the feasibility of change detection between a high resolution SAR image and a polarimetric SAR image. It highlights the interest of this configuration for change detection but also the analysis of these change areas through to the polarimetric information. The approach is applied to the case of urban areas.</p

Theory of evidence and non-exhaustive frames of discernment

SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1996 n.200 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc