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oe1(光电查) - 科学论文

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  • [IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Combination of Optical and SAR Sensors for Monitoring Biomass Over Corn Fields

    摘要: In this study, a cross-calibration approach was applied to combine RADARSAT-2 and RapidEye sensors for biomass monitoring over corn fields. First, RapidEye and RADARSAT-2 sensors were compared in terms of biomass estimation. Then the estimated biomass from RADARSAT-2 was cross-calibrated with respect to the biomass estimated from RapidEye. Combination of the optical and cross-calibrated Synthetic Aperture Radar (SAR) derived biomass was proposed to have higher temporal resolution biomass maps. Vegetation indices including normalized difference vegetation index (NDVI), red-edge triangular vegetation index (RTVI), simple ratio (SR) and red-edge simple ratio (SRre) were used for modeling of biomass estimation from RapidEye. Water Cloud Model (WCM) was also used for biomass estimation from RADARSAT-2. Data collected during SMAP Validation Experiment 2012 (SMAPVEX12) field campaign was used for validation. The results demonstrate that the accuracies of biomass estimations from RapidEye and RADARSAT-2 are close. For RapidEye, the highest accuracies derived from RTVI index with correlation coefficient (R) of 0.92 and Root Mean Square of (RMSE) of 118.18 ????/??2. The R values derived from RADARSAT-2 is 0.83 and its RMSE is 171.93 ????/??2. After cross-calibration of the biomass derived from RADARSAT-2 versus those derived from RapidEye, the RMSE of estimates dropped by 18.86 ????/??2.

    关键词: Biomass,Corn,RADARSAT-2,RapidEye

    更新于2025-09-09 09:28:46

  • [IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - The Biomass SAR Instrument: Development Status and Performance Overview

    摘要: Biomass, ESA’s 7th Earth Explorer mission, will provide the first global scale, systematic measurements of the global distribution of biomass. This paper describes the Biomass instrument, an imaging synthetic aperture radar (SAR) at P-band. It provides an overview of the mission application and architecture, the instrument requirements and technical concept, and the predicted instrument performance.

    关键词: SAR,Instrument,Biomass,P-band,Reflector Antenna

    更新于2025-09-09 09:28:46

  • A Remote Sensing Algorithm of Column-Integrated Algal Biomass Covering Algal Bloom Conditions in a Shallow Eutrophic Lake

    摘要: Column integrated algal biomass provides a robust indicator for eutrophication evaluation because it considers the vertical variability of phytoplankton. However, most remote sensing-based inversion algorithms of column algal biomass assume a homogenous distribution of phytoplankton within the water column. This study proposes a new remote sensing-based algorithm to estimate column integrated algal biomass incorporating different possible vertical profiles. The field sampling was based on five surveys in Lake Chaohu, a large eutrophic shallow lake in China. Field measurements revealed a significant variation in phytoplankton profiles in the water column during algal bloom conditions. The column integrated algal biomass retrieval algorithm developed in the present study is shown to effectively describe the vertical variation of algal biomass in shallow eutrophic water. The Baseline Normalized Difference Bloom Index (BNDBI) was adopted to estimate algal biomass integrated from the water surface to 40 cm. Then the relationship between 40 cm integrated algal biomass and the whole column algal biomass at various depths was built taking into consideration the hydrological and bathymetry data of each site. The algorithm was able to accurately estimate integrated algal biomass with R2 = 0.89, RMSE = 45.94 and URMSE = 28.58%. High accuracy was observed in the temporal consistency of satellite images (with the maximum MAPE = 7.41%). Sensitivity analysis demonstrated that the estimated algal biomass integrated from the water surface to 40 cm has the greatest influence on the estimated column integrated algal biomass. This algorithm can be used to explore the long-term variation of algal biomass to improve long-term analysis and management of eutrophic lakes.

    关键词: algal bloom,remote sensing,Lake Chaohu,column integrated algal biomass

    更新于2025-09-09 09:28:46

  • LiDAR and Orthophoto Synergy to optimize Object-Based Landscape Change: Analysis of an Active Landslide

    摘要: Active landslides have three major effects on landscapes: (1) land cover change, (2) topographical change, and (3) above ground biomass change. Data derived from multi-temporal Light Detection and Ranging technology (LiDAR) are used in combination with multi-temporal orthophotos to quantify these changes between 2006 and 2012, caused by an active deep-seated landslide near the village of Doren in Austria. Land-cover is classified by applying membership-based classification and contextual improvements based on the synergy of orthophotos and LiDAR-based elevation data. Topographical change is calculated by differencing of LiDAR derived digital terrain models. The above ground biomass is quantified by applying a local-maximum algorithm for tree top detection, in combination with allometric equations. The land cover classification accuracies were improved from 65% (using only LiDAR) and 76% (using only orthophotos) to 90% (using data synergy) for 2006. A similar increase from respectively 64% and 75% to 91% was established for 2012. The increased accuracies demonstrate the effectiveness of using data synergy of LiDAR and orthophotos using object-based image analysis to quantify landscape changes, caused by an active landslide. The method has great potential to be transferred to larger areas for use in landscape change analyses.

    关键词: data synergy,above ground biomass,LiDAR,Vorarlberg,Landslide,orthophotos,OBIA,land cover change

    更新于2025-09-09 09:28:46

  • Green Energy based Thermochemical and Photochemical Hydrogen Production

    摘要: A significant amount of hydrogen is required to satisfy the hydroprocessing needs of petroleum refinery, natural gas cleaning, and biofuel upgrading. Meanwhile, hydrogen is a very promising candidate of energy due to its high energy output per mass unit as compared to other sources of energy. In this article, the production of hydrogen is overviewed from the traditional technology as the thermochemical processes of fossil fuels to the current development in photoelectrochemical processes or even hybrid technologies. The catalysts for methane reforming and visible-light absorption were summarized. Both processes employ oxides as the catalyst. Because catalytic oxides are mostly lack of visible-light absorption function, the visible-light absorption properties could be rendered by doping these oxides with metal, nitrogen, or even sulfur. Further complete substitution of the oxygen atoms leads to non-oxide catalyst. Moreover, multidimensional photochemical catalysts have acquired more attention over traditional powered catalysts. Finally, a vision is exhibited for the efficiency and the future trends on production of H2.

    关键词: Tri-reforming,catalyst,Biomass,Electrolysis,Dry Reforming,Hydrogen Production,Steam Reforming,Methane,Autothermal Reforming,Solar energy,Gasification,Coal

    更新于2025-09-09 09:28:46

  • An approach to estimating forest biomass change over a coniferous forest landscape based on tree-level analysis from repeated lidar surveys

    摘要: Forests represent a significant opportunity for carbon sequestration, but quantifying biomass change at the landscape scale and larger remains a challenge. Here we develop an approach based on repeated tree-level analysis using high-resolution airborne lidar (around 8 pulses/m2). The study area was 53 km2 of actively managed coniferous forestland in the Coast Range Mountains in western Oregon. The study interval was 2006–2012. Tree heights and crown areas were determined from the lidar data using point cloud clustering. Biomass per tree was estimated with allometry. Tree-level data (N = 14,709) from local USDA Forest Service Forest Inventory and Analysis plots provided the basis for the allometry. Estimated biomass change over the 6-year interval averaged ?1.3 kg m?2 year?1, with the average gain in undisturbed areas of 1.0 kg m?2 year?1. Full harvest occurred on 3% of the area per year. For surviving trees, the mean change in height was 0.5 m year?1 (SD = 0.3) and the mean change in biomass was 45.3 kg year?1 (SD = 6.7). The maximum bin-average increase in biomass per tree (57.3 kg year?1) was observed in trees of intermediate height (35–40 m). In addition to high spatially resolved forest biomass change, potential applications of tracking of repeated tree-level surveys include analysis of mortality. In this relatively productive forest landscape, an interval of 6 years between lidar acquisitions was adequate to resolve significant changes in tree height and area-wide biomass.

    关键词: carbon sequestration,forest biomass,lidar,tree-level analysis,coniferous forest

    更新于2025-09-04 15:30:14

  • Biomass Burning Aerosols in the Amazon Basin, Characterised by Lidar, Optical Particle Counters, and Modelling

    摘要: Biomass burning is the second largest global source of anthropogenic aerosols, and South America is one of the major source regions. In the dry season, the atmosphere of the Amazon basin features a remarkable haze, with layers containing high loadings of smoke. Aerosols with different degrees of ageing, are encountered in the boundary layer and the free troposphere. The South American Biomass Burning Analysis (SAMBBA) was an intensive observation campaign that involved measurements of the Amazonian atmosphere using the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 research aircraft in September-October 2012.

    关键词: lidar,modelling,optical particle counters,aerosols,Biomass burning,Amazon basin

    更新于2025-09-04 15:30:14

  • Effect of supplemental blue light intensity on the growth and quality of Chinese kale

    摘要: The influence of blue light on the growth and quality of vegetables is controversial, since both positive and negative effects have been observed on different varieties of vegetables and most research has been conducted with a combination of light spectrums. In this work, we investigated the effects of supplemental blue light intensity on growth, nutritional quality, and health-promoting compounds of Chinese kale (Brassica alboglabra Bailey) using only blue (460 nm) light-emitting diodes 10 days before harvest in a greenhouse under ambient light conditions. Four blue-light treatments were conducted (0, 50, 100, and 150 μmol m?2 s?1, named T0, T50, T100, and T150, respectively) with 12 h (6:00–18:00) of light treatment per day. The growth of Chinese kale plants was improved by supplemental blue light. The fresh and dry weights of Chinese kale plants were significantly higher under T50 and T100 than those in the other treatments. The content of chlorophyll b and total chlorophyll increased significantly under T50, and the content of carotenoids increased significantly under T150. The contents of soluble sugars and free amino acids were significantly increased under the blue light treatments. The nitrate content decreased with increasing blue light intensity, while the anthocyanin content increased. The contents of vitamin C in T50 and total phenolic compounds in T150 were significantly higher than in T0. The flavonoid contents were significant higher in T50 and T150, and significantly lower in T100. Our results show that blue light can influence the growth and quality of Chinese kale and 50 μmol m?2 s?1 of supplemental blue light might be the most feasible light intensity for Chinese kale production.

    关键词: Photosynthetic photon flux density,Biomass,Health-promoting compounds,Brassica alboglabra,Nutritional quality

    更新于2025-09-04 15:30:14

  • [Sustainable Energy Developments] Geothermal,Wind and Solar Energy Applications in Agriculture and Aquaculture || Chapter 7: Fundamentals of solar energy

    摘要: Modern agricultural systems are characterized by the intensive and optimal use of land and water, turning agricultural exploitation into a semi-industrial concept. Greenhouses are systems suitable both for zones with unfavorable climatic conditions – allowing crop growth regardless of the ambient temperature – and for regions with less restrictive weather – with the aim of increasing crop productivity and improving fruit quality. In this context, a secure and environmentally friendly energy supply must be considered, for any power range or circumstance, including for stand-alone installations. Crop growth is primarily determined by climate and the amount of water and fertilizers applied through irrigation. Therefore, greenhouses are ideal for farming because they allow one to optimize these physical parameters, via the photosynthetic process (Ramírez-Arias et al., 2012), to enhance biomass production. This manipulation requires energy consumption, depending on the crop’s physiological requirements, and the production patterns adopted for yield quantity and timing. The present general concern on the development of more efficient and sustainable productive activities has increased interest in the evaluation of alternatives to the conventional energy sources in the sector; presently many are involved in processes for assessing the environmental feasibility and technological development of such alternatives (Antón et al., 2007; Bojacá et al., 2014; Martínez-Blanco et al., 2011; Page et al., 2012; Romero-Gámez et al., 2012; Torrellas et al., 2013; van der Werf et al., 2014). This work aims to provide an overview of the existing options for the integration of renewable sources in greenhouses located in semi-arid regions where, for example, the high availability of solar radiation facilitates its use for the fulfillment of a certain percentage of the heat and/or electricity loads of greenhouses. Accordingly, this overview contains the basic technological aspects of the main renewable technologies applicable in greenhouses, some simplified design tools and criteria for their selection. Finally, it includes a summary of selected experiences in this field. The main objective is to contribute to a better understanding of the technologies that should support the promotion and development of projects for the implementation of renewable energies in agriculture.

    关键词: biomass,geothermal energy,wind energy,semi-arid climates,crop growth control,renewable energy,photovoltaic,greenhouses,energy efficiency,solar energy

    更新于2025-09-04 15:30:14

  • [IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - The Potential of Sentinel Satellites for Large Area Aboveground Forest Biomass Mapping

    摘要: Estimation of aboveground forest biomass is critical for regional carbon policies and sustainable forest management. Both passive optical remote sensing and active microwave remote sensing can play an important role in the monitoring of forest biomass. In this study, the recently launched Sentinel-2 Multi Spectral Instrument satellite and Sentinel-1 SAR satellite systems were evaluated and integrated to investigate the relative strengths of each sensor for mapping aboveground forest biomass at a regional scale. The Australian state of Victoria, with its wide range of forest vegetation was chosen as the study area to demonstrate the scalability and transferability of the approach. In this study aboveground forest biomass (AGB) was defined as the tons of carbon per hectare for the aboveground components (stem, branches, leaves) of all live large trees greater than 10 cm in diameter at breast height (DBHOB). Sentinel-2 and Sentinel-1 data were fused within a machine learning framework using a boosted regression tree model and high-quality ground survey data. Multi-criteria evaluations showed the use of the two independent and fundamentally different Sentinel satellite systems were able to provide robust estimates (R2 of 0.62, RMSE of 32.2 t.C.ha-1) of aboveground forest biomass, with each sensor compensating for the weakness (cloud perturbations and spectral saturation for Sentinel 2, and sensitivity to ground moisture for Sentinel 1) of each other. As archives for Sentinel-2 and Sentinel-1 continue to grow, mapping aboveground forest biomass and dynamics at moderate resolution over large regions should become increasingly feasible.

    关键词: Sentinel-2,machine learning,data fusion,Sentinel-1,Victoria,boosted regression tree model,Australia,biomass estimation

    更新于2025-09-04 15:30:14