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- 摘要
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- 实验方案
- 产品
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Operation and Development of a Center for Collective Use in the Field of Photonics
摘要： Management and procedural principles underlying the operation and development of the Center for Collective Use of high-precision measurement technologies in the field of photonics for the purpose of assuring equal access of scientists to expensive research and measurement complexes, scientific equipment, and plants are set forth. A number of different procedural approaches to assuring an exhaustive integral supply of the Center for Collective Use with scientific equipment are considered using as an example the creation of a measurement and calibration complex for metrological assurance of measurements in the field of microwave photonics.
关键词： photometry,system for remote sensing of the Earth,center for collective use,radio photonic channel,spectroradiometry,optical radiometry,photonics
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Dual Circularly Polarized Antennas with Low Cross-Polarization for GNSS-R Applications
摘要： Global Navigation System-Reflectometry (GNSS-R), has gained increasing interests as an efficient tool for remote sensing. It is based on the concept of utilizing the received signals reflected from the Earth’s surface. Several GNSS-R system configurations were proposed depending on different retrieval algorithms. In a GNSS-R system, the antenna plays a key role as a receiving component. In this paper, in-situ measurements using a commercial dual circular polarized antenna receiving both the left-hand and right-hand circular polarization reflected from the ground are analyzed. A low cost and compact dual-port circular polarized patch antenna is designed and realized to overcome the limitations of the previous configuration. The prototype shows a low level of cross polarization suitable for GNSS-R application.
关键词： circular polarization,dual polarization,patch antenna,remote sensing of soil,GNSS-R
更新于2025-09-04 15:30:14
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[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 - Diversifying Deep Multiple Choices for Remote Sensing Scene Classification
摘要： Recently, deep models have shown powerful ability for remote sensing scene representation. However, the training process of these deep methods requires large amount of labelled samples while usual remote sensing image datasets cannot provide enough training samples. Therefore, the learned model is usually suboptimal. To solve the problem, this work focuses on obtaining multiple choices by training multiple models simultaneously, and then the human oracle can choose a proper one from these choices. However, training several models separately usually makes the obtained results similar. This paper tries to diversify the obtained choices by encouraging the obtained choices to repulse from each other. Experiments are conducted on Ucmerced Land Use dataset to validate the effectiveness of the proposed method to provide multiple diversified choices.
关键词： Remote Sensing Image,Cross Entropy,Diversity,Convolutional Neural Network,Classification
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Antenna and Propagation Aspects of a Future GNSS-Reflectometry Mission
摘要： Global System Reflectometry (GNSS-R) is a passive sensing method to measure properties of the Earth’s surface, of oceans, or of the atmosphere by analyzing reflected navigation signals from GNSS satellites such as GPS (Global Positioning System). The reflected signals can be measured with ground based, air borne, or space based sensors, and the applications reach from altimetry, ocean wind retrieval, soil moisture to vegetation growth analysis. The principle of GNSS-R was presented a few decades ago. Meanwhile, GNSS-R is already used in ground based GNSS sites, performance analyses/demonstrations for in-orbit measurements are carried out, and orbit missions are ongoing. The present study introduces the concept and some of its variations. It describes initial and ongoing research, and it presents propagation aspects of a future CubeSat mission to measure the height of oceans and ice areas and study the sea ice extend. Finally, the design of a L-band patch antenna array is presented that will be used to detect both the direct and the reflected GNSS signals.
关键词： L-band patch antenna array,GNSS-reflectometry,altimetry,PRETTY mission,propagation,low earth orbit,remote sensing
更新于2025-09-04 15:30:14
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[IEEE 2018 10th IAPR Workshop on Pattern Recognition in Remote Sensing (PRRS) - Beijing (2018.8.19-2018.8.20)] 2018 10th IAPR Workshop on Pattern Recognition in Remote Sensing (PRRS) - Extracting Rural Residential Areas from High-Resolution Remote Sensing Images in the Coastal Area of Shandong, China Based on Fast Acquisition of Training Samples and Fully Convoluted Network
摘要： Automatic extraction of rural residential areas from high-resolution remote sensing images in large regions is a challenging task, because all kinds of background features, such as roads, green houses, and urban areas, must be excluded effectively by an extraction method. For the unsupervised methods of rural residential areas extraction, it is difficult to manually design features which are only sensitive to residential areas. At the same time, the supervised methods utilize training samples to obtain the discrimination between rural residential areas and the background features. However, manual labeling in large regions is tedious and time-consuming. The drawbacks of the existing methods for extracting rural residential areas limit their application in large regions. Therefore, we proposed a novel methodology for extracting rural residential areas in large regions based on fast acquisition of training samples and the fully convoluted network (FCN). A block-based method was proposed to extract rural residential areas rapidly and acquire training samples. Then, the large amount of training samples were used to train the FCN for rural residential area extraction. Finally, all ZY-3 satellite images in in the coastal area of Shandong, China were feed into the FCN, and the extraction result were obtained.
关键词： rural residential areas,training samples,high-resolution remote sensing,fully convoluted network
更新于2025-09-04 15:30:14
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Fluorescence quantum yield of CDOM in coastal zones of the Arctic seas
摘要： Along with traditional optical indices, calculated from absorption and ?uorescence spectra to describe chromophoric dissolved organic matter (CDOM) naturally occurring in water, the ?uorescence quantum yield (FQY) becomes signi?cant. Knowledge of CDOM optical properties is important for satellite remote sensing as well as for lidar ground-true measurements. The FQY as a function of excitation wavelength within 240–500 nm range for a variety of the Arctic shelf waters was determined for the ?rst time in order to identify the characteristic chromophores peculiar to di?erent regions of the Arctic basin a?ected by freshwater runo?. The surface water samples were collected during several cruises in 2015–2017 in the following sites: the mouth areas of the Khatanga and Lena Rivers (the Laptev Sea), the delta area of the Northern Dvina River (the White Sea), desalinated waters of the Kara Sea (in?uenced by freshwater of the Ob and Yenisei Rivers) and the East Siberian Sea (in?uenced by freshwaters of the Indigirka and Kolyma Rivers), as well the shelf areas of those seas not a?ected by terrigenous runo?. To characterize DOM, conventional optical indices SR, HIX, and BIX were calculated. In most cases, important humic character of DOM was established, while the contribution of autochthonous organic matter varied from low to intermediate level. For the samples with terrestrial impact, the FQY decreased from excitation at 240 nm to 270–280 nm and then increased, demonstrating two peaks at 340 and 380 nm, with constant decrease towards longer excitation wavelengths; at λex = 380 nm FQY varied from 1.4% to 3.1%. In some cases, additional maximum at 270 nm of FQY-excitation dependency was observed as an indicator of autochthonous nature of biological material. Minimal FQY was measured for the White Sea surface waters, the maximal for the Laptev and East Siberian seas.
关键词： optical properties,fluorescence quantum yield,CDOM,Arctic seas,remote sensing
更新于2025-09-04 15:30:14
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Development of a radiative transfer model for the determination of toxic gases by Fourier transform–infrared spectroscopy with a support vector machine algorithm
摘要： This report describes a radiative transfer model for Fourier transform-infrared (FT-IR) spectroscopy to create close-to-reality toxic gas spectra by reflecting the unique spectral responses of detectors and using the atmospheric radiative transfer code, MODTRAN. This system can be highly useful in overcoming the limitations for measuring toxic gases in open environments. The emulated gas spectra can be used to train support vector machine (SVM) for chemical gas detection. Its detection performance is evaluated with nerve agents (tabun, sarin, soman, and cyclosarin) and a simulant gas (sulfur hexafluoride) for indoor and outdoor experiments by using two off-the-shelf FT-IR gas detectors. The experimental results show that the proposed SVM algorithm successfully detected and classified targeted gases while reducing false negative and false positive detection rates.
关键词： support vector machine gas detection,Fourier transform infrared remote sensing,support vector machine,hyperspectral imaging,Fourier transform – infrared spectroscopy,stand-off detection
更新于2025-09-04 15:30:14
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Remote sensing lake level fluctuations in response to a changing climate
摘要： Lakes and reservoirs have long been regarded as a solution to the water problems of semi-arid regions, as well as a mitigation measure against the impacts of climate change and climate variability. However, the ability of these lakes to mitigate the impacts of climate change itself has largely been untested. In this study, we tested the utility of remote sensing in monitoring fluctuations in Lake Mutirikwi’s surface area. Furthermore, we determined the nature and strength of the relationship between Lake Mutirikwi’s surface area and annual rainfall total with a view to understanding the sensitivity of the lake volume to the main input of water in the lake – precipitation. Results of the study show that the volume of the lake fluctuated by between 1% and as much as 90% of the lake’s capacity. We also found a significant relationship (r = 0.84, p = 0.002) between the surface area of the lake and the amount of rainfall received in the second half of the rainfall season. We conclude that Lake Mutirikwi is so sensitive to fluctuations in rainfall amounts that it doesn’t offer much mitigation cover in the face of a changing and highly variable climate.
关键词： remote sensing,climate change,Lake Mutirikwi,lake surface area
更新于2025-09-04 15:30:14
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An Investigation of Optically Very Thin Ice Clouds from Ground-Based ARM Raman Lidars
摘要： Optically very thin ice clouds from the Cloud-Aerosol Lidar and Infrared Path?nder Satellite Observations (CALIPSO) and ground-based Raman lidars (RL) at the atmospheric radiation measurement (ARM) sites of the Southern Great Plains (SGP) and Tropical Western Paci?c (TWP) are analyzed. The optically very thin ice clouds, with ice cloud column optical depths below 0.01, are about 23% of the transparent ice-cloudy pro?les from the RL, compared to 4–7% from CALIPSO. The majority (66–76%) of optically very thin ice clouds from the RLs are found to be adjacent to ice clouds with ice cloud column optical depths greater than 0.01. The temporal structure of RL-observed optically very thin ice clouds indicates a clear sky–cloud continuum. Global cloudiness estimates from CALIPSO observations leveraged with high-sensitivity RL observations suggest that CALIPSO may underestimate the global cloud fraction when considering optically very thin ice clouds.
关键词： remote sensing,ice cloud detection,ice cloud optical depth,lidars
更新于2025-09-04 15:30:14
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[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 - Effect of a Thin DRY Snow Layer on the Lake ICE Thickness Measurement using Wideband Autocorrelation Radiometry
摘要： Wideband autocorrelation radiometry (WiBAR) is a new method to remotely sense the microwave propagation time τdelay of multi-path microwave emission of low loss layered surfaces such as dry snowpack and freshwater lake ice pack. The microwave propagation time τdelay through the pack yields a measure of its vertical extent; thus, this technique is a direct measurement of depth. However, the presence of a different low loss layer on the lake ice pack such as dry snow pack introduces another multi-path interference, which can effect the lake ice pack thickness measurement. We present a simple geophysical forward model for the multipath interference phenomenon and derive the WiBAR system requirements needed to correctly measure the ice pack thickness. An X-band instrument fabricated from commercial-off-the-shelf (COTS) components are used to measure the thickness freshwater lake ice at the University of Michigan Biological Station. Ice thickness retrieval is demonstrated from nadir to 73.9?.
关键词： Snowpack,autocorrelation,icepack,microwave radiometry,remote sensing
更新于2025-09-04 15:30:14