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oe1(光电查) - 科学论文

1196 条数据
?? 中文(中国)
  • Optical Remote Sensing Potentials for Looting Detection

    摘要: Looting of archaeological sites is illegal and considered a major anthropogenic threat for cultural heritage, entailing undesirable and irreversible damage at several levels, such as landscape disturbance, heritage destruction, and adverse social impact. In recent years, the employment of remote sensing technologies using ground-based and/or space-based sensors has assisted in dealing with this issue. Novel remote sensing techniques have tackled heritage destruction occurring in war-conflicted areas, as well as illicit archeological activity in vast areas of archaeological interest with limited surveillance. The damage performed by illegal activities, as well as the scarcity of reliable information are some of the major concerns that local stakeholders are facing today. This study discusses the potential use of remote sensing technologies based on the results obtained for the archaeological landscape of Ayios Mnason in Politiko village, located in Nicosia district, Cyprus. In this area, more than ten looted tombs have been recorded in the last decade, indicating small-scale, but still systematic, looting. The image analysis, including vegetation indices, fusion, automatic extraction after object-oriented classification, etc., was based on high-resolution WorldView-2 multispectral satellite imagery and RGB high-resolution aerial orthorectified images. Google Earth? images were also used to map and diachronically observe the site. The current research also discusses the potential for wider application of the presented methodology, acting as an early warning system, in an effort to establish a systematic monitoring tool for archaeological areas in Cyprus facing similar threats.

    关键词: image analysis,satellite data,remote sensing archaeology,looting,Cyprus

    更新于2025-09-23 15:23:52

  • [IEEE 2017 4th International Conference on Opto-Electronics and Applied Optics (Optronix) - Kolkata (2017.11.2-2017.11.3)] 2017 4th International Conference on Opto-Electronics and Applied Optics (Optronix) - A noble approach to light the path trail using swarm technology

    摘要: Swarm intelligence (Intro SI) is the collective behaviour of decentralized, self-organized systems, natural or artificial. It is many minds working together. It is the first step in allowing people to pool their knowledge and insights into a single elevated intelligence. The objective is to light on a path trail by the leading robot, so that the rest of the robots could follow the trail to work as a unified system, thereby reducing time and manpower.

    关键词: adaptive path exploration,swarm intelligence,Robot sensing systems,cognitive map generation,neighbouring robots,path trail information

    更新于2025-09-23 15:23:52

  • Identifying Emerging Reservoirs along Regulated Rivers Using Multi-Source Remote Sensing Observations

    摘要: The number of reservoirs is rapidly increasing owing to the growth of the world’s economy and related energy and water needs. Yet, for the vast majority of reservoirs around the world, their locations and related information, especially for newly dammed reservoirs, are not readily available due to financial, political, or legal considerations. This study proposes an automated method of identifying newly dammed reservoirs from time series of MODIS-derived NDWI (normalized difference water index) images. Its main idea lies in the detection of abrupt changes in the NDWI time series that are associated with land-to-water conversion due to the reservoir impoundment. The proposed method is tested in the upper reach of the Yellow River that is severely regulated by constructed reservoirs. Our results show that five newly dammed reservoirs were identified in the test area during 2000–2018. Validated against high-resolution Google Earth imagery, our method is effective to determine both locations of the emerging medium-size reservoirs and the timing of their initial water impoundments. Such information then allows for a refined calculation of the reservoir inundation extents and storage capacities through the combination of higher-resolution Landsat imagery and SRTM DEM. The comparison of our estimated reservoir areas and capacities against documented information further indicates that the integration of multi-mission remote sensing data may provide useful information for understanding reservoir operations and impacts on river discharges. Our method also demonstrates a potential for regional or global inventory of emerging reservoirs, which is crucial to assessing human impacts on river systems and the global water cycle.

    关键词: reservoir,time series,NDWI,remote sensing,BFAST,Yellow River

    更新于2025-09-23 15:23:52

  • FusionCNN: a remote sensing image fusion algorithm based on deep convolutional neural networks

    摘要: In remote sensing image fusion field, traditional algorithms based on the human-made fusion rules are severely sensitive to the source images. In this paper, we proposed an image fusion algorithm using convolutional neural networks (FusionCNN). The fusion model implicitly represents a fusion rule whose inputs are a pair of source images and the output is a fused image with end-to-end property. As no datasets can be used to train FusionCNN in remote sensing field, we constructed a new dataset from a natural image set to approximate MS and Pan images. In order to obtain higher fusion quality, low frequency information of MS is used to enhance the Pan image in the pre-processing step. The method proposed in this paper overcomes the shortcomings of the traditional fusion methods in which the fusion rules are artificially formulated, because it learns an adaptive strong robust fusion function through a large amount of training data. In this paper, Landsat and Quickbird satellite data are used to verify the effectiveness of the proposed method. Experimental results show that the proposed fusion algorithm is superior to the comparative algorithms in terms of both subjective and objective evaluation.

    关键词: Convolutional neural networks,Deep learning,Remote sensing image fusion,Image enhancement

    更新于2025-09-23 15:23:52

  • PhenoFly Planning Tool: flight planning for high-resolution optical remote sensing with unmanned areal systems

    摘要: Background: Driven by a huge improvement in automation, unmanned areal systems (UAS) are increasingly used for field observations and high-throughput phenotyping. Today, the bottleneck does not lie in the ability to fly a drone anymore, but rather in the appropriate flight planning to capture images with sufficient quality. Proper flight preparation for photography with digital frame cameras should include relevant concepts such as view, sharpness and exposure calculations. Additionally, if mapping areas with UASs, one has to consider concepts related to ground control points (GCPs), viewing geometry and way-point flights. Unfortunately, non of the available flight planning tools covers all these aspects. Results: We give an overview of concepts related to flight preparation, present the newly developed open source software PhenoFly Planning Tool, and evaluate other recent flight planning tools. We find that current flight planning and mapping tools strongly focus on vendor-specific solutions and mostly ignore basic photographic properties—our comparison shows, for example, that only two out of thirteen evaluated tools consider motion blur restrictions, and none of them depth of field limits. In contrast, PhenoFly Planning Tool enhances recent sophisticated UAS and autopilot systems with an optical remote sensing workflow that respects photographic concepts. The tool can assist in selecting the right equipment for your needs, experimenting with different flight settings to test the performance of the resulting imagery, preparing the field and GCP setup, and generating a flight path that can be exported as waypoints to be uploaded to an UAS. Conclusion: By considering the introduced concepts, uncertainty in UAS-based remote sensing and high-throughput phenotyping may be considerably reduced. The presented software PhenoFly Planning Tool (https://shiny.usys.ethz.ch/PhenoFlyPlanningTool) helps users to comprehend and apply these concepts.

    关键词: Flight planning,Ground control point (GCP),High-throughput phenotyping,Viewing geometry,Low-altitude remote sensing,Mapping from imagery

    更新于2025-09-23 15:23:52

  • Multi-source Remote Sensing Image Registration Based on Contourlet Transform and Multiple Feature Fusion

    摘要: Image registration is an indispensable component in multi-source remote sensing image processing. In this paper, we put forward a remote sensing image registration method by including an improved multi-scale and multi-direction Harris algorithm and a novel compound feature. Multi-scale circle Gaussian combined invariant moments and multi-direction gray level co-occurrence matrix are extracted as features for image matching. The proposed algorithm is evaluated on numerous multi-source remote sensor images with noise and illumination changes. Extensive experimental studies prove that our proposed method is capable of receiving stable and even distribution of key points as well as obtaining robust and accurate correspondence matches. It is a promising scheme in multi-source remote sensing image registration.

    关键词: contourlet transform,multi-source remote sensing image registration,multi-direction gray level co-occurrence matrix,multi-scale circle Gaussian combined invariant moment,Feature fusion

    更新于2025-09-23 15:23:52

  • Kinetics of singlet oxygen sensing using 9-substituted anthracene derivatives$$^{\#}$$#

    摘要: Singlet oxygen (1O2), the lowest excited-state of molecular oxygen receives great attention in basic research and clinical and industrial settings. Despite several spectroscopic methods available for 1O2 sensing, fluorescence sensing receives great attention, for which many fluorogenic sensors based on substituted anthracene are reported. Nonetheless, the roles of substituents on the sensing efficiency, in terms of detection time, remain largely unknown. In this work, we examine the 1O2 sensing efficiency of a fluorescence sensor based on a coumarin–anthracene conjugate, which is an electron donor-acceptor dyad, and compare the efficiency with that of 9-methylanthracene. Here, 1O2 is generated using the standard photosensitizer Rose Bengal, which is followed by estimation of the rate of reaction of 1O2 to the sensor and 9-methylanthracene. The second order reaction rate of the sensor is an order of magnitude less than that of 9-methylanthracene. The lower reactivity of the sensor to 1O2 suggests that the roles of substituents, such as electronic interactions, steric interactions and the reactivity of precursor complexes, on sensing efficiency should be carefully considered during construction of fluorogenic molecular sensors.

    关键词: photochemistry,reaction kinetics,anthracene,fluorescence sensing,Singlet oxygen

    更新于2025-09-23 15:23:52

  • Sol–Gel Spin-Coating Followed by Solvothermal Synthesis of Nanorods-Based ZnO Thin Films: Microstructural, Optical, and Gas Sensing Properties

    摘要: Zinc oxide thin films with nanorod morphology were investigated for microstructural and optical properties as well as their performance as a liquid petroleum gas sensing material. A two-step synthesis procedure consisting of sol–gel spin-coating and solvothermal methods was employed where several factors such as rational utilization of metal precursors, solvent, stabilizing, and structure directing agents, a repetitive drying-coating process, as well as post-thermal annealing were found influential to obtain qualified nanorods and a final homogeneous thin film. Compositional and optical investigations were pursued to characterize features, namely morphology, poly crystallinity, porous structure, nanocrystallite size, lattice oriented growth, textural atomic ratio, lattice purity and transparency, phonon and exciton transitions, as well as the formed structural defects via field-emission scanning electron microscopy, x-ray diffraction, energy-dispersive x-ray, UV–Vis spectroscopy, Raman, and photoluminescence techniques. The as-prepared thin film was then used as an active LPG sensing material via a home-made gas sensor where the control sensing parameters were chamber testing temperature and gas concentration. Results showed a quantitative response of 92.7% as sensor sensitivity at an operation temperature of 250°C and a LPG concentration of 800 ppm in addition to fast response and recovery times of 44.1 s and 218.7 s, respectively.

    关键词: Zinc oxide nanorods,thin film,optical characteristics,gas sensing,microstructural properties,liquid petroleum gas

    更新于2025-09-23 15:23:52

  • Investigation of Strongly Hydrophobic and Thick Porous Silicon Stain Films Properties

    摘要: Porous silicon (PSi) structures with strong hydrophobicity have been achieved by chemical etching of p-type silicon substrates in a solution based on hydrofluoric acid solution (HF) and vanadium oxide (V2O5). The surface morphology and microstructure of the elaborated structured silicon surfaces were investigated using Scanning Electron Microscope (SEM), contact angle and Fourier Transform Infrared spectroscopy (FTIR). The results show that the obtained structures exhibit hierarchically porous surfaces with porous pillars of silicon (PPSi) and an important hydrophobicity of the surface. The electrical properties of those PPSi structures were investigated in presence of 10 ppm of NO2 gas. The response time was about 30s at room temperature. Our results demonstrate that PPSi/Si are highly hydrophobic for long time and suitable for applications in the field of self-cleaning and may be a good candidate in elaborating practical NO2 sensors.

    关键词: Porous silicon,Hydrophobicity,Gas sensing applications,Pillars structures

    更新于2025-09-23 15:23:52

  • Glint Removal Assessment to Estimate the Remote Sensing Reflectance in Inland Waters with Widely Differing Optical Properties

    摘要: The quality control of remote sensing reflectance (Rrs) is a challenging task in remote sensing applications, mainly in the retrieval of accurate in situ measurements carried out in optically complex aquatic systems. One of the main challenges is related to glint effect into the in situ measurements. Our study evaluates four different methods to reduce the glint effect from the Rrs spectra collected in cascade reservoirs with widely differing optical properties. The first (i) method adopts a constant coefficient for skylight correction (ρ) for any geometry viewing of in situ measurements and wind speed lower than 5 m·s?1; (ii) the second uses a look-up-table with variable ρ values accordingly to viewing geometry acquisition and wind speed; (iii) the third method is based on hyperspectral optimization to produce a spectral glint correction, and (iv) computes ρ as a function of wind speed. The glint effect corrected Rrs spectra were assessed using HydroLight simulations. The results showed that using the glint correction with spectral ρ achieved the lowest errors, however, in a Colored Dissolved Organic Matter (CDOM) dominated environment with no remarkable chlorophyll-a concentrations, the best method was the second. Besides, the results with spectral glint correction reduced almost 30% of errors.

    关键词: remote sensing accuracy,inland waters,optically complex systems

    更新于2025-09-23 15:23:52