Towards a comparison of spaceborne and ground-based spectrodirectional reflectance data

Almost all natural surfaces exhibit an individual anisotropic reflectance behaviour due to the contrast between the optical properties of surface elements and background and the geometric surface properties of the observed scene. The resulting bidirectional effects are present in all reflectance data and thus occur as well in various vegetation indices (VI’s) retrieved from multiangular data. No matter whether these effects are considered as noise or as a source of additional information, accurate knowledge about their magnitude is important. This preliminary study is based on data of the spaceborne ESA-mission CHRIS (Compact High Resolution Imaging Spectrometer) onboard PROBA-1 and on ground-based spectrodirectional measurements performed with the dual view field goniometer system FIGOS. The objectives of this study are focused on directional effects in CHRIS and FIGOS reflectance data of a Triticale field as well as on the variability of retrieved vegetation indices for selected view angles in both multiangular datasets

Building a Data Set over 12 Globally Distributed Sites to Support the Development of Agriculture Monitoring Applications with Sentinel-2

Developing better agricultural monitoring capabilities based on Earth Observation data is critical for strengthening food production information and market transparency. The Sentinel-2 mission has the optimal capacity for regional to global agriculture monitoring in terms of resolution (10–20 meter), revisit frequency (five days) and coverage (global). In this context, the European Space Agency launched in 2014 the “Sentinel­2 for Agriculture” project, which aims to prepare the exploitation of Sentinel-2 data for agriculture monitoring through the development of open source processing chains for relevant products. The project generated an unprecedented data set, made of “Sentinel-2 like” time series and in situ data acquired in 2013 over 12 globally distributed sites. Earth Observation time series were mostly built on the SPOT4 (Take 5) data set, which was specifically designed to simulate Sentinel-2. They also included Landsat 8 and RapidEye imagery as complementary data sources. Images were pre-processed to Level 2A and the quality of the resulting time series was assessed. In situ data about cropland, crop type and biophysical variables were shared by site managers, most of them belonging to the “Joint Experiment for Crop Assessment and Monitoring” network. This data set allowed testing and comparing across sites the methodologies that will be at the core of the future “Sentinel­2 for Agriculture” system.Instituto de Clima y AguaFil: Bontemps, Sophie. Université Catholique de Louvain. Earth and Life Institute; BélgicaFil: Arias, Marcela. Universite de Toulose - Le Mirail. Centre d’Etudes Spatiales de la BIOsphère; FranciaFil: Cara, Cosmin. CS Romania S.A.; RumaniaFil: Dedieu, Gérard. Universite de Toulose - Le Mirail. Centre d’Etudes Spatiales de la BIOsphère; FranciaFil: Guzzonato, Eric. CS Systèmes d’Information; FranciaFil: Hagolle, Olivier. Universite de Toulose - Le Mirail. Centre d’Etudes Spatiales de la BIOsphère; FranciaFil: Inglada, Jordi. Universite de Toulose - Le Mirail. Centre d’Etudes Spatiales de la BIOsphère; FranciaFil: Matton, Nicolas. Université Catholique de Louvain. Earth and Life Institute; BélgicaFil: Morin, David. Universite de Toulose - Le Mirail. Centre d’Etudes Spatiales de la BIOsphère; FranciaFil: Popescu, Ramona. CS Romania S.A.; RumaniaFil: Rabaute, Thierry. CS Systèmes d’Information; FranciaFil: Savinaud, Mickael. CS Systèmes d’Information; FranciaFil: Sepulcre, Guadalupe. Université Catholique de Louvain. Earth and Life Institute; BélgicaFil: Valero, Silvia. Universite de Toulose - Le Mirail. Centre d’Etudes Spatiales de la BIOsphère; FranciaFil: Ahmad, Ijaz. Pakistan Space and Upper Atmosphere Research Commission. Space Applications Research Complex. National Agriculture Information Center Directorate; PakistánFil: Bégué, Agnès. Centre de Coopération Internationale en Recherche Agronomique pour le Développerment; FranciaFil: Wu, Bingfang. Chinese Academy of Sciences. Institute of Remote Sensing and Digital Earth; República de ChinaFil: De Abelleyra, Diego. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; ArgentinaFil: Diarra, Alhousseine. Université Cadi Ayyad. Faculté des Sciences Semlalia; MarruecosFil: Dupuy, Stéphane. Centre de Coopération Internationale en Recherche Agronomique pour le Développerment; FranciaFil: French, Andrew. United States Department of Agriculture. Agricultural Research Service. Arid Land Agricultural Research Center; ArgentinaFil: Akhtar, Ibrar ul Hassan. Pakistan Space and Upper Atmosphere Research Commission. Space Applications Research Complex. National Agriculture Information Center Directorate; PakistánFil: Kussul, Nataliia. National Academy of Sciences of Ukraine. Space Research Institute and State Space Agency of Ukraine; UcraniaFil: Lebourgeois, Valentine. Centre de Coopération Internationale en Recherche Agronomique pour le Développerment; FranciaFil: Le Page, Michel. Université Cadi Ayyad. Faculté des Sciences Semlalia. Laboratoire Mixte International TREMA; Marruecos. Universite de Toulose - Le Mirail. Centre d’Etudes Spatiales de la BIOsphère; FranciaFil: Newby, Terrence. Agricultural Research Council; SudáfricaFil: Savin, Igor. V.V. Dokuchaev Soil Science Institute; RusiaFil: Verón, Santiago Ramón. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; ArgentinaFil: Koetz, Benjamin. European Space Agency. European Space Research Institute; ItaliaFil: Defourny, Pierre. Université Catholique de Louvain. Earth and Life Institute; Bélgic

The fourth phase of the radiative transfer model intercomparison (RAMI) exercise : Actual canopy scenarios and conformity testing

The RAdiative transfer Model Intercomparison (RAMI) activity focuses on the benchmarking of canopy radiative transfer (RT) models. For the current fourth phase of RAMI, six highly realistic virtual plant environments were constructed on the basis of intensive field data collected from (both deciduous and coniferous) forest stands as well as test sites in Europe and South Africa. Twelve RT modelling groups provided simulations of canopy scale (directional and hemispherically integrated) radiative quantities, as well as a series of binary hemispherical photographs acquired from different locations within the virtual canopies. The simulation results showed much greater variance than those recently analysed for the abstract canopy scenarios of RAMI-IV. Canopy complexity is among the most likely drivers behind operator induced errors that gave rise to the discrepancies. Conformity testing was introduced to separate the simulation results into acceptable and non-acceptable contributions. More specifically, a shared risk approach is used to evaluate the compliance of RI model simulations on the basis of reference data generated with the weighted ensemble averaging technique from ISO-13528. However, using concepts from legal metrology, the uncertainty of this reference solution will be shown to prevent a confident assessment of model performance with respect to the selected tolerance intervals. As an alternative, guarded risk decision rules will be presented to account explicitly for the uncertainty associated with the reference and candidate methods. Both guarded acceptance and guarded rejection approaches are used to make confident statements about the acceptance and/or rejection of RT model simulations with respect to the predefined tolerance intervals. (C) 2015 The Authors. Published by Elsevier Inc.Peer reviewe

Comprehensive overview of the structure and regulation of the glucocorticoid receptor

Glucocorticoids are among the most prescribed drugs worldwide for the treatment of numerous immune and inflammatory disorders. They exert their actions by binding to the glucocorticoid receptor (GR), a member of the nuclear receptor superfamily. There are several GR isoforms resulting from alternative RNA splicing and translation initiation of the GR transcript. Additionally, these isoforms are all subject to several transcriptional, post-transcriptional, and post-translational modifications, all of which affect the protein's stability and/or function. In this review, we summarize recent knowledge on the distinct GR isoforms and the processes that generate them. We also review the importance of all known transcriptional, post-transcriptional, and post-translational modifications, including the regulation of GR by microRNAs. Moreover, we discuss the crucial role of the putative GR-bound DNA sequence as an allosteric ligand influencing GR structure and activity. Finally, we describe how the differential composition and distinct regulation at multiple levels of different GR species could account for the wide and diverse effects of glucocorticoids

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Environmental changes. Monitoring land cover changes in the Siberian region of Komi. Estimate of the vegetation trend using remote sensing

This report is focused on the individuation of the land cover changes and on the vegetation trend estimation of the Siberian Republic of Komi and supported by the following objectives: understanding which kind of help the remote sensing is able to provide, which social and economics causes drive the degradation and deforestation processes and which would be the consequences of the ecosystems degradation. Using the software ENVI 4.8 and ArcGIS 10, as principal instruments, the images provided by Globe Cover - land cover and Landsat mosaics have been processed to obtain the extent of the unsupervised classifications and the consequent land cover and change detections products, supported by the estimation of errors. The final products showed an high level of deforestation, also on virgin forest, related to the local pulp and paper companies

Ray tracing for modeling of small footprint airborne laser scanning returns

Airborne Laser Scanning (ALS) has been established as a valuable tool for the estimation of biophysical canopy variables, such as tree height and vegetation density. However, up to now most approaches are built upon empirical stand based methods for linking ALS data with the relevant canopy properties estimated by field work. These empirical methods mostly comprise regression models, where effects of site conditions and sensor configurations are contained in the models. Thus, these models are only valid for a specific study, which renders inter-comparison of different approaches difficult. Physically based approaches exist e.g. for the estimation of tree height and tree location, however systematic underestimation depending upon sampling and vegetation type remains an issue. Using a radiative transfer model that builds on the foundation of the Open-Source ray tracer povray we are simulating return signals for two ALS system settings (footprint size and laser wavelength). The tree crowns are represented by fractal models (L-systems), which explicitly resolve the position and orientation of single leafs. The model is validated using ALS data from an experiment with geometric reference targets. We were able to reproduce the effects of target size and target reflectance that were found in the real data with our modeling approach. A sensitivity study was carried out in order to determine the effect of properties such as beam divergence (0.5, 1, and 2 mrad), canopy reflectance (laser wavelength, 1064 and 1560 nm) on the ALS return statistics. Using the two laser wavelengths above, we were able to show that the laser wavelength will not significantly influence discrete return statistics in our model. It was found that first echo return statistics only differ significantly if the footprint size was altered by a factor of 4. Last return distributions were significantly different for all three modelled footprint sizes, and we were able to reproduce the effect of an increased number of ground returns for large footprint sizes. These forward simulations are a first step in the direction of physically based derivation of biophysical ALS data products and could improve the accuracy of the derived parameters by establishing correction terms

Capability of the Sentinel 2 mission for tropical coral reef mapping and coral bleaching detection

The Sentinel 2 mission offers continuity of service for the moderate resolution multispectral SPOT XS and Landsat Thematic Mapper series sensors, but also offers several design improvements that may lead to enhanced capability in coral reef mapping applications. In this study modeling and simulated image analyses were conducted to evaluate the relative capability of the Sentinel 2 instrument design compared to SPOT-4 and Landsat ETM+, for mapping bathymetry and benthic composition, and for coral bleaching detection. The analyses involved propagating noise and environmental uncertainties through a radiative transfer model inversion to quantify uncertainty in retrievable parameters from each sensor. The experiment structure included factors for sensor-environmental noise, band choice, and complexity of benthic reflectance model. Results indicate that while variables related to reef 'health' such as coral mortality and algal cover cannot be mapped accurately by this class of instrument; Sentinel 2 does have improved ability for discrimination of reef benthic composition over SPOT-4 and Landsat ETM+. The key enabling design factors are the narrowness of bands, increased spatial resolution and additional band at 443. nm; instrument noise was a less significant factor. Rapid revisit times, global coverage, and freely available data suggest the potential for time series analyses. Sentinel 2 may also be capable of bleaching detection by change analysis given effective methods for precise cross-image image radiometric and spatial alignment