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Effect of Open Soil Surface Patterns on Soil Detectability Based on Optical Remote Sensing Data
摘要： Arable soils are subjected to the altering influence of agricultural and natural processes determining surface feedback patterns therefore affecting their ability to reflect light. However, remote soil mapping and monitoring usually ignore information on surface state at the time of data acquisition. Conducted research demonstrates the contribution of surface feedback dynamics to soil reflectance and its relationship with soil properties. Analysis of variance showed that the destruction surface patterns accounts for 71% of spectral variation. The effect of surface smoothing on the relationships between soil reflectance and its properties varies. In the case of organic matter and medium and coarse sand particles, correlation decreases with the removement of surface structure. For particles of fine sand and coarse silt, grinding changes spectral areas of high correlation. Partial least squares regression models also demonstrated variations in complexity, R2cv and RMSEPcv. Field dynamics of surface feedback patterns of arable soils causes 22–46% of soil spectral variations depending on the growing season and soil type. The directions and areas of spectral changes seem to be soil-specific. Therefore, surface feedback patterns should be considered when modelling soil properties on the basis of optical remote sensing data to ensure reliable and reproducible results.
关键词： digital soil mapping,remote sensing,spectral reflectance,surface feedback
更新于2025-09-23 15:21:21
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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 - Effects of Nonuniform Vertical Profiles of Suspended Particles on Remote Sensing Reflectance of Turbid Water
摘要： The in situ data and forward radiative transfer model were applied to simulate the nonuniform vertical profiles of suspended particles in turbid Poyang Lake. The sensitivity of remote sensing reflectance (Rrs) associated with nonuniform water column showed correlation with suspended particulate matter (SPM), wavelength and water depth. Different nonuniform vertical profiles could cause more than 108% overestimation or 60% underestimation of Rrs at most. The uncertainties in Rrs decreased with the increase of water depth. The sensitive wavelength moved to longer wavelength and the maximum influence water depth let up, along with the increase in concentration of SPM in surface water. A dimensionless parameter made up of beam attenuation coefficient of surface water, water depth and SPM vertical distribution, was established to quantitatively describe the effects of vertically nonuniform water column on Rrs.
关键词： vertically nonuniform water column,water optical properties,remote sensing reflectance
更新于2025-09-23 15:21:21
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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 - Developing a Sandbox Environment for Prosail, Suitable for Education and Research
摘要： We introduce the Interactive Visualization of Vegetation Reflectance Models (IVVRM) tool as a sandbox environment for the PROSAIL family of radiative transfer models. Every interaction with the Graphical User Interface (GUI) invokes a new model run of the updated parameter set and the results are instantly plotted on the screen. The quasi-simultaneous response allows easy hands-on practice with PROSAIL for education and training as well as straightforward inversions of biophysical variables from spectra by manual curve fitting. It is shown that expert knowledge can improve the quality of parameter retrieval and reveal sources of uncertainties in the field data and the models. IVVRM is free of charge and available as an application through the EnMAP-Box 3.0.
关键词： reflectance modelling,model environment,PROSAIL,radiative transfer,EnMAP-Box
更新于2025-09-23 15:21:21
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Development of Near-Infrared Reflectance Spectroscopy (NIRS) Calibrations for Traits Related to Ethanol Conversion from Genetically Variable Napier Grass (Pennisetum purpureum Schum.)
摘要： Napier grass (Pennisetum purpureum Schum.) is one of the highest-yielding feedstocks for bio-based products and biofuel in semi-tropical areas of the USA and the world. Thirty genetically diverse Napier grass accessions were selected from a germplasm nursery in Tifton, GA and analyzed for fiber, ash, nitrogen (N) concentration, and biochemical conversion to ethanol. A near-infrared reflectance spectroscopy (NIRS) calibration was developed from this material to predict ethanol production, xylans, N concentration, and ash by separating leaves and stems and correlating with wet chemistry analyses. The high diversity of material from dwarf material with high leaf and stem digestibility to taller and more productive Napier grass cultivars resulted in high correlations with predicted results for in vitro dry matter digestibility (2 = 0.93), neutral detergent fiber (r2 = 0.83), acid detergent fiber (r2 = 0.95), ethanol (r2 = 0.90), nitrogen (r2 = 0.99), and ash (r2 = 0.98). This information will allow faster evaluation of Napier grass biomass for use by industry or geneticists.
关键词： Biomass,Near-infrared reflectance spectroscopy (NIRS),Forage,Biofuels
更新于2025-09-23 15:21:21
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Cutaneous erysipeloid metastasis of cholangiocarcinoma and evaluation by in?vivo reflectance confocal microscopy
摘要： Cutaneous metastases are relatively uncommon, occurring in only 0.7% to 9% of all internal malignancies. Cholangiocarcinoma is a rare bile duct neoplasm that accounts for less than 2% of malignancies. Although it is well known that cholangiocarcinoma metastasizes to the lungs, liver, peritoneum, and retroperitoneal lymph nodes, a retrospective review of the literature from 1978 to 2014 indicates only 30 cases of cutaneous cholangiocarcinoma, with 17 cases presenting without concurrent metastasis in other sites. Among these patients, the cutaneous metastatic disease occurred evenly at adjacent and distant sites, presenting as 0.3-cm to 4-cm erythematous papules or nodules with or without ulceration. The median overall survival after diagnosis of cutaneous cholangiocarcinoma metastasis is 4 months. Paradoxically, single-site metastases carry a significantly worse prognosis than multiple-site metastases and may be attributed to difficulty in identifying a singular lesion. In vivo reflectance confocal microscopy (RCM) is a novel, noninvasive diagnostic alternative to skin biopsy with comparable insurance reimbursement that captures real-time, high-resolution, cellular-level images from the skin surface down to the reticular dermis (up to 300 μm depth). This modality forgoes traumatic biopsy and has been used for diagnosis and monitoring of skin cancers and inflammatory dermatoses.
关键词： cholangiocarcinoma,erysipeloid,cutaneous metastasis,reflectance confocal microscopy
更新于2025-09-23 15:21:21
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The application of proximal visible and near-infrared spectroscopy to estimate soil organic matter on the Triffa Plain of Morocco
摘要： Soil organic matter (SOM) is a fundamental soil constituent. The estimation of this parameter in the laboratory using the classical method is complex time-consuming and requires the use of chemical reagents. The objectives of this study were to assess the accuracy of two laboratory measurement setups of the VIS-NIR spectroscopy in estimating SOM content and determine the important spectral bands in the SOM estimation model. A total of 115 soil samples were collected from the non-root zone (0-20 cm) of soil in the study area of the Triffa Plain and then analysed for SOM in the laboratory by the Walkley–Black method. The reflectance spectra of soil samples were measured by two protocols, Contact Probe (CP) and Pistol Grip (PG)) of the ASD spectroradiometer (350-2500 nm) in the laboratory. Partial least squares regression (PLSR) was used to develop the prediction models. The results of coefficient of determination (R2) and the root mean square error (RMSE) showed that the pistol grip offers reasonable accuracy with an R2 = 0.93 and RMSE = 0.13 compared to the contact probe protocol with an R2 = 0.85 and RMSE = 0.19. The near-Infrared range were more accurate than those in the visible range for predicting SOM using the both setups (CP and PG). The significant wavelengths contributing to the prediction of SOM for (PG) setup were at: 424, 597, 1432, 1484, 1830 ,1920, 2200, 2357 and 2430 nm, while were at 433, 587, 1380, 1431, 1929, 2200 and 2345 nm for (CP) setup.
关键词： soil organic matter,SOM analysis.,VIS-NIR spectroscopy,reflectance spectra,SOM estimation
更新于2025-09-23 15:21:01
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EXPRESS: Mid-Infrared Reflectance Spectroscopy of Oil Sands Minerals Based on Tunable Quantum Cascade Lasers
摘要： Minerals play an important role in the oil sands extraction efficiency. It is thus important to assess the major mineral abundance in oil sands ores. This paper presents the application of tunable quantum cascade lasers for mid-infrared reflectance spectroscopy on oil sands minerals. The investigations and results show a new tool to determine oil sands mineral type and to determine potentially quartz and clay contents.
关键词： Mid-infrared spectroscopy,mid-IR,reflectance spectroscopy,oil sands,QCL,quantum cascade lasers
更新于2025-09-23 15:21:01
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Improving the performance of Cu2ZnSnS4 thin film solar cell by engineering the ITO film thickness
摘要： In this work, the effects of tin doped indium oxide (ITO) thin films with different thicknesses (50 nm–476 nm) on the optoelectronic performance were investigated. Meanwhile, the sputtered ITO layers were annealed at 180°C for 60min under air atmosphere. The result indicated that the electro-optical properties of ITO films with the thickness (383 nm) were optimum, and the corresponding resistivity and average reflectance in the spectrum range (350–860 nm) were 4.73 × 10?4 Ω cm and lower than 20%, respectively. Finally, impacts of ITO layers with various thicknesses on the performance of CZTS solar cells were also studied. The open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF) and power conversion efficiency (PCE) of CZTS solar cells had been increased significantly from 576 mV to 636 mV, from 15.8 mA/cm2 to 20.2 mA/cm2, from 31.2% to 43.4% and from 3.04% to 5.56%, respectively, and eventually the highest PCE of CZTS solar cell based on 383 nm ITO window layer thickness was 5.56%.
关键词： Power conversion efficiency,ITO films,Reflectance,Optoelectronic performance
更新于2025-09-23 15:21:01
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Towards an on-chip optical microsystem for spectroscopic detection of gastrointestinal dysplasia
摘要： This paper presents a CMOS optical microsystem with a 4×4 photodiodes array and their readout electronics, based on 16 light-to-frequency converters, and 16 high selective optical filters, for spectrophotometric measurement of diffuse reflectance and fluorescence signals, applied to the detection of gastrointestinal dysplasia. The photodiodes array is based on n+/p-epilayer junction silicon photodiodes. Their readout electronics outputs a digital signal, with a frequency proportional to the photodiode current, featuring a sensitivity of 26 Hz/nA at 550 nm, a spectral resolution of 9 MHz and a power consumption of 1 mW. The optical filters are based on 16 thin-film narrow-band Fabry-Perot resonators, in which dielectric mirrors are used. They feature high transmittances and low full-width-half-maximum. Experimental measurements, using phantoms representative of the main absorbing, scattering and fluorescence properties of gastrointestinal tissues, proved the viability of the CMOS optical microsystem with the optical filters to extract those signals, when comparing the obtained results with commercial equipment. The implemented apparatus is ready to be used as a portable system on a surgery room to verify the total removing of gastrointestinal cancer tissue. Moreover, the developed approach is a step forward in the implementation of a gastrointestinal dysplasia detection miniaturized tool.
关键词： Fluorescence,CMOS optical microsystem,Optical filters,Gastrointestinal dysplasia,Diffuse reflectance
更新于2025-09-23 15:21:01
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SSC prediction of cherry tomatoes based on IRIV-CS-SVR model and near infrared reflectance spectroscopy
摘要： As one of the most important indexes of internal quality testing of fruit, soluble solids content (SSC) is significant for its rapid and efficient nondestructive testing by using near infrared reflectance spectroscopy (NIRS). In this article, 126 cherry tomatoes were selected as the research object. Reflectance spectra data of 228 bands in cherry tomatoes were acquired by the near infrared spectrometer and SSC was measured by the hand-held refractometer. Savitzky–Golay (SG) combined with multiplicative scatter correction (MSC) was used to preprocess the spectral data to reduce the effects of light scattering and other noise. Then, the dimensions of spectral data were reduced by iteratively retaining informative variables (IRIV) algorithm and 10 characteristic wavelengths were obtained, which were 1,080.37, 1,113.62, 1,117.3, 1,297.57, 1,301.02, 1,538.32, 1,540.40, 1,590.72, 1,615.94, and 1,636.89 nm, respectively. Subsequently, support vector regression (SVR) and its two optimization models, PSO-SVR and CS-SVR, were respectively used to establish SSC prediction models based on full spectra and characteristic spectra. The experimental results showed the IRIV-CS-SVR model for SSC prediction achieved the accuracy with R2 C of 0.9845. Thus, it is feasible to use NIRS with IRIV-CS-SVR to make a rapid and efficient nondestructive SSC prediction of cherry tomatoes.
关键词： IRIV-CS-SVR model,SSC prediction,cherry tomatoes,near infrared reflectance spectroscopy
更新于2025-09-23 15:21:01