水质检测传感器研究的新进展

水质检测传感器主要包括化学水质检测传感器、生物学水质检测传感器、光学水质检测传感器和谐振式水质检测传感器四类。综述了水质传感器的原理、应用、研究现状和各自的特点,对水质检测传感器现存的问题进行了阐述。对我国生活饮用水卫生标准的主要常规指标进行了介绍,并与其它国家的几种主要用水标准进行了对比。     

鄱阳湖水质检测的无线传感网络设计

在研究无线传感器网络基础上,对远程实时鄱阳湖水质监测系统进行了分析。应用S3C44BO和WISMOQ2403设计了无线传感器网络的硬件系统,并使用该网络对pH值等水质参数进行监测。实验结果表明,该系统能对水质参数进行实时有效的采集。     

基于无线传感器的水质监测系统仿真设计

研究水质监测系统问题,传统水质监测系统不能对水质参数进行在线监测,难以准确检测水质参数的动态变化,水质参数检测误差大。为提高水质参数的检测精度,提出一种无线传感器网络水质监测系统。系统综合利用了无线传感器网络和GPRS无线通信优点,构建一个灵活、快速的水质监测系统,从而实现对水质参数进行远程、实时监测。仿真结果表明,改进系统能够很好满足水质智能、在线检测和实时传输要求,提高了水质参数监测精度,检测结果稳定、可扩展性强。     

基于无线传感器网络的水质监测系统设计

在研究无线传感器网络及Zigbee协议标准的基础上,对远程实时水质监测系统进行了分析.提出了基于Zigbee无线传感器网络与互联网结合的远程实时水质监测系统架构.设计了基于无线传感器的水质监测网络体系结构,实现了水质监测参数的荻取及传输.     

基于优化深度置信网络的多传感器水质监测研究

为了满足多种水环境的大范围、精准监测需求,提出了基于优化深度置信网络的多传感器水质监测方法。设置水质监测标准,作为水质等级的判定条件。优化设计水体温度、PH值、溶解氧、浊度等传感器设备,利用优化深度置信网络选择多传感器的安装位置。利用多传感器采集水环境数据并完成融合处理,通过多个水质监测指标的计算以及与设置标准的比对,得出多传感器水质监测的可视化输出结果。通过性能测试实验得出结论：优化设计方法的水质监测范围为2041.79平方千米,浊度、pH值、溶解氧和氨氮浓度指标的监测误差分别为0.005FTU、0.07、0.05mg/L和0.007mg/L,均低于传统方法,且满足预设条件。     

用北斗定位的城市远程水质监测系统

为了扩大水质监测的网络覆盖范围、优化数据云存储功能，设计了一种远程水质监测系统。该系统由终端设备、物联网云平台、Web应用组成。终端设备由STM32单片机、无线通信模块与多种传感器组成，STM32单片机获取传感器数据进行处理并发送至阿里云物联网平台分析并存储，管理人员在Web网页查看上传数据。     

水质监测无线传感器网络的硬件设计

针对传统水质监测系统不能对水质参数进行实时在线监测,难以准确检测水质参数的动态变化、水质参数检测误差大等问题,提出了水质监测无线传感器网络（ WSNs）的硬件设计方案。系统主要通过核心单片机CC2530实现传感器节点设计,采用太阳能电池板进行供电,同时设计了采集温度、pH 值的硬件电路,并对硬件电路进行了稳定性试验。在 IRA 开发环境下,进行传感器节点和协调器的编程,使之能够进行通信。实验结果表明：系统温度、pH值的平均相对误差分别为3.06%,1.64%,提高了监测精度。     

基于无线传感器网络技术的水质监测系统

随着人们对赖以生存的水环境的重视,水质实时在线监测系统需求迫切。基于对无线传感器网络技术的研究,以无线传感器网络为通讯手段,结合水质评价模型,设计了一个水质在线监测系统。实现对特定水域的实时监测,对提高水质保护和水资源合理利用具有一定的意义。     

基于无线传输的水质监测生物传感器设计研究

为弥补传统水质监测耗时长、不能及时反映水质污染状况且智能度低的问题,设计了基于无线传输的水质监测生物传感器.以监测水质生化需氧量(BOD)为监测主体,集成温度(T)、酸碱度(pH)及溶解氧(DO)共计四项水质监测项目.论述了BOD生物传感器的工作原理,设计了多参数集成型水质监测生物传感器的整体结构,阐述了测定多参数水质指标及后端无线传输等过程,为水质监测生物传感器向高度智能化方向发展及仪器的下一步开发提供了基础.     

基于WSN的数据融合在水质监测中的研究

多传感器数据融合是一种数据处理方法,可以对来自多个传感器的数据进行多方面、多层次的处理,从而产生更有意义的信息,而这种信息是单一传感器难以获得的。通过在水质监测应用背景下研究基于WSN的数据融合,提出了一种针对水质监测的两级数据融合模型：处理传感器所采集到的监测数据时,对于同类型的数据采用自适应加权理论进行第一级数据融合;对于不同类型的数据采用模糊综合评价理论进行第二级数据融合。对巢湖流域水样监测的实验结果表明,这种采用自适应加权理论和模糊综合评价理论相结合的数据融合模型,能够有效降低监测网络的数据传输量,降低监测数据的误差,提高水质状态监测的可信度。     

多时相ERS-2 SAR图像在作物分类中的预处理方法研究

雷达遥感具有全天候、全天时的工作能力,适合于农业遥感监测的时效要求,在农业应用上有很大的潜力。以多时相ERS-2 SAR图像在农作物分类中的应用为例,根据试验区主要农作物的后向散射特性、物候,选择SAR图像的时相。对不同时相的SAR图像的辐射标定、几何校正和噪声平滑等预处理方法进行了研究。     

Research on Glacier Change Monitoring in Nianchu River Basin

This study extracted the local glacier information over the Nianchu river basin in the Tibet in 1996 and 2005 by using ice index,snow index and water index of Landsat TM\|5 multi\|spectral images,and Synthetic Aperture Radar (SAR)intensity and coherence information of ERS\|1/2 and Envisat ASAR.The optimized features were determined by their classification accuracies based on Support Vector Machine (SVM)classifier.The result showed that the composition of multi\|spectral and SAR features could effectively discriminate the water and ice from other types,with overall accuracies of 84% and 85% in 1996 and 2005,respectively.Based on the thematic information of these two years,the changes of the local glacial area and boundary were detected.The result showed that the glacial area of the Nianchu river basin was reduced by 154.7 km²,which mainly caused by the climate warming.     

基于MODIS NDVI的LandsatTM影像地形阴影区光谱信息恢复方法研究

遥感为获取山区生态环境与资源信息提供了重要的观测手段。然而受地形遮蔽影响,山区光学影像大量的地形阴影给山区土地覆被解译以及生态参量的遥感反演带来了巨大困难。针对地形阴影光谱信息的恢复,提出了一种基于MODIS NDVI的Landsat TM影像地形阴影区光谱信息恢复方法。该方法首先利用MODIS上午、下午星(Terra和Aqua)不同时间过境能够对地形阴影区信息实现互补的特点,采用最大值合成法合成MODIS上、下午星16dNDVI产品(MOD13Q1和MYD13Q1),获得低空间分辨率影像上的阴影区光谱信息;在此基础上,考虑MODIS与Landsat的观测角度、光谱差异,设置滑动窗口及筛选规则提取MODIS与TM影像相匹配的同质纯像元;基于中、低空间分辨率影像中均匀同质像元存在一定统计关系的假设,进一步建立同质区域中TM影像光照区域与对应MODIS NDVI的回归树模型,利用该统计关系和阴影区MODIS的NDVI信息推导得出地形阴影区的光谱信息。将阴影光谱信息恢复后的影像与SCS+C校正后的影像进行比较和分析,结果表明该方法恢复得到的地形阴影的光谱信息能够更好地反映阴影区信息,同时光谱保真程度较好。随着越来越多的中高空间分辨率卫星影像的发展,采用多源卫星数据进行山地地形阴影区信息恢复将成为一个新的发展趋势,该方法以期为同类影像处理提供参考。     

An approach for assessing boreal forest conditions based on combined use of satellite SAR and multi-spectral data

The degree and spatial distribution of boreal forest ecosystem degradation in Russia are not well known. The objective of this study is to develop an interpretation basis for analysis of satellite remote sensing data using a set of indicators characterizing the ecological situation and the degree of industrial pollution. European Remote Sensing Satellite (ERS) Synthetic Aperture Radar (SAR) and Landsat Multi-Spectral Scanner (MSS) data are used in combination for this purpose, along with an exceptionally extensive in situ data set of ground measurements of spectral radiance of pine biocenose components, and the results of moss chemistry and bio-indicator studies from the ecologically stressed St Petersburg region. It is shown that ERS SAR images provide an assessment of forested area distribution and forest type classification. The main factors of variability in parameters such as Normalized Difference Vegetation Index (NDVI) that are most strongly related to in situ indicators reflecting the state of the forest are identified. A supervised classification of forest degradation was performed on the basis of the NDVI values from the Landsat images. The results obtained make it possible to specify the areas at a local level and perform regional assessments. The potential for multi-temporal ERS SAR and multi-spectral sensor observations to trace the dynamics of changes in forest ecosystems is evaluated.     

Regression-based synergy of optical, shortwave infrared and microwave remote sensing for monitoring the grain-size of intertidal sediments

A method is developed for monitoring the sediment grain-size of intertidal flats in the Westerschelde (southwest Netherlands), using information from both space-borne microwave (SAR) and optical/shortwave infrared remote sensing. Estimates of the backscattering coefficient were extracted from time-series of C-band ERS SAR imagery. Surface reflectance in the visible, near-infrared (VNIR) and shortwave infrared (SWIR) part of the electromagnetic spectrum, as well as spectral indices, were derived from matching multi-temporal Landsat TM imagery. In addition, surface reflectances were derived from a set of airborne multispectral (VNIR) CASI images, and hyperspectral (VNIR) measurements using a field spectroradiometer. The data were related to matching field measurements of surface characteristics, including sediment properties. Regression-based algorithms were developed to map the spatio-temporal distribution of mud content using (a) the C-band SAR backscattering coefficient, (b) surface reflectance in the green and SWIR, and (c) a combination of these, with corroborative field measurements. Mud content of the sediment has been successfully mapped by all three algorithms, but a combination of information from microwave and VNIR/SWIR provided best results. The algorithms were generally consistent in time, making them suitable for generating time-series and for monitoring. However, they should be validated and calibrated in order to be applicable to other intertidal areas.     

Land Change Patterns and Driving Mechanism in Beijing since 1990 based on GEE Platform

Land-cover and land-use dynamics is a key component for global change,and it is a significant form of the impact of human activities on physical environment.Basing Google Earth Engine platform and Classification And Regression Tree method,selected seven types of cultivated land,forest,grassland,wetland,water body,artificial surface and bare land as classification system,the paper used Landsat 5 TM and Landsat 8 OLI images to interpret the land\|cover and land\|use since 1990 of Beijing.Simultaneously,the paper analyzed and summarized the character of land\|use changing and driving force.The results show that：(1) GEE has outstanding advantages in remote sensing data analysis and processing at regional scales.(2) The CART method has high accuracy of remote sensing classification,and the overall accuracy of validation of 6 land cover products is above 93%.The spatial consistency of 2010 products and GlobeLand30\|2010 data showed that the spatial consistency ratios of woodland,water body and cultivated land were 84.28%,74.75%and 73.56% respectively.The spatial consistency of the distribution is 74.0%.(3) The main land types in Beijing were cultivated land,woodland and artificial surface,and the area accounted for about 90%.During the period from 1990 to 2016,the artificial surface and woodland area increased,and the cultivated land and water were shrinking.The artificial surface area increase of 1 371 km²,and cultivated land shrinkage 40%;On Beijing plain area,artificial surface by the circle of “spread pie” expansion trend to “blossom everywhere” expansion trend;The expansion of the artificial surface is mainly achieved through the encroachment of cultivated land.We constructed a multidimensional stepwise linear equation model to analyze the driving force of land type change,indicated that rapid population growth,rapid economic development,government\|related policies and other socio\|economic development factors jointly drive the Beijing land-cover/land-use evolution process.     

Geomorphological changes associated with underground coal mining in the Fushun area,northeast China revealed by multitemporal satellite remote sensing data

Fushun is a famous coal-mining city in northeastern China with more than 100 years of history. Long-term underground coal mining has caused serious surface subsidence in the eastern part of the city. In this study, multitemporal and multisource satellite remote sensing data were used to detect subsidence and geomorphological changes associated with underground coal mining over a 10-year period (1996–2006). A digital elevation model (DEM) was generated through Synthetic Aperture Radar (SAR) interferometry processing using data from a pair of European Remote Sensing Satellite (ERS) SAR images acquired in 1996. In addition, a Shuttle Radar Topography Mission (SRTM) DEM obtained from data in 2000 and an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) DEM from 2006 were used for this study. The multitemporal DEMs indicated that the maximum vertical displacement due to subsidence was around 13 m from 1996 to 2006. Multitemporal ASTER images showed that the flooded water area associated with subsidence had increased by 1.73 km² over the same time period. Field investigations and ground level measurements confirmed that the results obtained from the multitemporal remote sensing data agreed well with ground truth data. This study demonstrates that DEMs derived from multisource satellite remote sensing data can provide a powerful tool to map geomorphological changes associated with underground mining activities.     

Estimation of Forest Aboveground Biomass and Canopy Heightin Jiangxi Province Using GLAS and Landsat TM Images

Aiming at the problem that optical remote sensing cannot estimate forest biomass exactly because it’s easily affected by the weather and hard to penetrate the canopy of the forest.Using Jiangxi forest as the study area,established forest canopy height and forest biomass model by GLAS waveform data,integrating multispectral data(TM) and filed survey data.The study results show:(1) using waveform feature parameter,terrain feature parameters and field survey data to build forest canopy height model can eliminate the terrain influence and obtain the discrete canopy height.(2) Combined with the NDVI and discrete canopy height can be carried out large scale continuous forest canopy height mapping.(3) Power function relationship between canopy height and forest biomass can be used to estimate forest biomass.In general,large\|footprint LiDAR combined with optical Landsat TM data can give full paly to the advantages of multi\|source remote sensing and improve the precision of forest biomass inversion.     

Analytical algorithms for lake water TSM estimation for retrospective analyses of TM and SPOT sensor data

Suspended matter in inland waters is related to total primary production and fluxes of heavy metals and micropollutants such as PCBs. Synoptic information on suspended matter cannot be obtained from an in situ monitoring network since suspended matter is a spatially inhomogeneous parameter. This problem can be solved by the integrated use of remote sensing data, in situ data and water quality models. To enable retrospective model and remote sensing data comparison of suspended matter concentration and distribution, a methodology is required for processing satellite images that is independent of in situ measurements. Analytical optical modelling, based on knowledge of the in situ inherent optical properties, leads to reliable multi-temporal algorithms for estimating suspended matter concentration in lakes for the data from the SPOT and Landsat TM sensors. This methodology allows multi-temporal, multi-site and multi-instrument comparison of TSM maps derived from satellite imagery. This means that satellite sensor data can now become an independent measurement tool for water management authorities. The remote sensing maps showed that large gradients in TSM were observed for the various lakes as well as temporal changes of these spatial gradients. In situ point samples are shown to be not representative for suspended matter in the lakes.     

Cover The 1992 Etna lava flow imaged by Landsat TM

Abstract

This paper describes an experiment where sea water quality parameters were determined using data from the Landsat Thematic Mapper (TM) satellite remote sensing system over a coastal sewage outfall area. The parameters determined included turbidity, chlorophyll-a, chlorophyll-i, phaeopigment and total pigment. The area investigated was a sewage outfall site off the North Head of Sydney Harbour, Australia. The method used multiple regression to relate site sampled parameters to digital Landsat-TM data, and the results verified using data not used in the regression. Multiple correlation coefficients in excess of R = 0. 9 resulted from the regression analysis, which used Landsat-TM variables in a Chebyshev Series form. However due to the limited number of ocean samples only the results for turbidity were considered significant. Nevertheless a satisfactory methodology is proposed.