- 标题
- 摘要
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- 实验方案
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An assessment of semi-analytical models based on the absorption coefficient in retrieving the chlorophyll-a concentration from a reservoir
摘要： Monitoring chlorophyll-a (Chl-a) concentrations in inland waters is crucial for water quality management, since Chl-a is a proxy for phytoplankton biomass and, thus, for ecological health of a water environment. Chl-a concentration can be retrieved through the inherent optical properties (IOPs) of a water system, which, in turn, can be remotely sensed obtained. Quasi-analytical algorithm (QAA), originally developed for ocean waters, can also retrieve IOPs for inland waters after re-parameterizations. This study is aimed at assessing the performance of sixteen schemes composed by QAA original and re-parameterized versions followed by models that use absorption coefficients as inputs for estimating Chl-a concentration in Ibitinga reservoir, located at Tietê River cascading system, S?o Paulo State, Brazil. It was verified that only QAAV5 based schemes were able to obtain reasonable estimates for image data and that by four models tested presented similar and acceptable results for QAAV5 outputs. The best model were applied to a Ocean and Land Colour Instrument (OLCI) image. Light absorption in the reservoir showed to be dominated by colored dissolved organic matter (CDOM), and wide spatial and temporal variability of optical and water quality properties was observed.
关键词： water quality monitoring,satellite data.,Trophic status,inland water
更新于2025-09-23 15:23:52
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WaterSpy: A High Sensitivity, Portable Photonic Device for Pervasive Water Quality Analysis
摘要： In this paper, we present WaterSpy, a project developing an innovative, compact, cost-effective photonic device for pervasive water quality sensing, operating in the mid-IR spectral range. The approach combines the use of advanced Quantum Cascade Lasers (QCLs) employing the Vernier effect, used as light source, with novel, fibre-coupled, fast and sensitive Higher Operation Temperature (HOT) photodetectors, used as sensors. These will be complemented by optimised laser driving and detector electronics, laser modulation and signal conditioning technologies. The paper presents the WaterSpy concept, the requirements elicited, the preliminary architecture design of the device, the use cases in which it will be validated, while highlighting the innovative technologies that contribute to the advancement of the current state of the art.
关键词： Quantum Cascade Lasers,photonics,water quality monitoring,photodetectors
更新于2025-09-23 15:22:29
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Plastic fiber evanescent sensor in measurement of turbidity
摘要： The construction and working principles of a plastic fiber sensor for examining the level of turbidity is studied in this paper. This work focuses on designing an inexpensive turbidity sensor that incorporates a pair of multimode fibers (MMF) that are attached side by side and their beveled tips are mounted vertically. The efficiency of different beveled angles is evaluated by simulation with Tracepro software. The reflected signal is collected by immersing the sensor head into a water mixture and analyzed for various concentration. It was found that there is a linear increment of output intensity when concentration of mixture is increased. The turbidity sensor is tested with real samples that are collected from lake, river and coastal areas to demonstrate its consistency with commercial apparatus in natural compounds. The results showed that the proposed sensor structure is able to produce reliable results in a dynamic range of detection from 0 to 1000 Nephelometric Turbidity Unit (NTU) to facilitate practical field measurements.
关键词： Optical fiber sensor,Tracepro software,Water quality monitoring,Turbidity
更新于2025-09-23 15:21:01
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Physical and chemical reaction sensing in a mixed aqueous solution via metal‐organic framework thin‐film coated optical fiber
摘要： A metal-organic framework thin-film (UiO-66) optical fiber platform is built up as a data processing sensory system to detect water contaminations. A simple scale-up approach is utilized to design a water-stable UiO-66 sensor at the tip (end face) of a conventional single mode optical fiber (SMF-28) for detecting rhodamine-B and methyl viologen in a mixed aqueous solution. The optical detection method was based on Fabry–Perot Interferometry, and the interference signal was analyzed by the fast Fourier transform (FFT) technique. Combining two contaminants in water produces a complex physical and chemical phenomena, and the FFT clearly showed it as a particular frequency related to a specific analyte type.
关键词： organic contaminant,water quality monitoring,metal-organic frameworks,liquid sensors,fiber optic chemical sensors
更新于2025-09-11 14:15:04
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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 - Water Quality Analysis of Remote Sensing Images Based on Inversion Model
摘要： The spectrum of water is directly related to the composition of the water, so water quality can be estimated by spectral reflectance. In this paper, the inversion model of water quality parameters for remote sensing images is established, based on which the status of water pollution is analyzed. Firstly, the spectral information of water in studied area is extracted from remote sensing images. Then, the relationship between spectral reflectance and water quality parameters is modeled. The model is evaluated by the fitting SSE (Sum of the Squared Errors), R-square, RMSE (the Root Mean Squared Errors) and Adjusted R-square. When R-square and Adjusted R-square are close to 1 and the SSE and RMSE are close to 0, inversion model is considered to be built up successfully. The experiments are conducted on 14 Landsat 8 OLI images in recent four years and the results show that the model method can realize the analysis and monitoring of the water quality. The R-square of the permanganate and dissolved oxygen were 0.96 and 0.80 respectively, which satisfied the requirements of the application.
关键词： Remote sensing,inversion model,multi-temporal water quality monitoring
更新于2025-09-10 09:29:36