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1.
The ocean is an important component of the globalenvironment and must not be ignored in the assessmentof environmental risks, even when attention is focusedon land surface issues. This paper addresses the useof space techniques for remote sensing of the ocean,in the context of how marine environmental risks maybe monitored. Since there are several significantdifferences between remote sensing over land and oversea, the techniques specific to ocean observation arefirst reviewed, identifying what can be measured fromspace and what are the sampling capabilities andinherent limitations. Ocean environmental risks arethen identified at global, regional and local scales,and serve as examples of how space techniques can beused to address them. Finally operationalenvironmental monitoring and risk management is shownto require an integrated approach using models andmeasurements from space and at sea.  相似文献   

2.
基于基准场的地震红外异常分析技术   总被引:1,自引:0,他引:1  
从卫星红外遥感图像中识别和提取与构造活动有关的热异常信息,是地震红外遥感监测预警的关键技术.为消除遥感影像中的复杂背景影响以及实现红外异常信息的自动识别与提取,本文提出了一种基于基准场的地震红外异常分析技术(IAARF),其核心是利用已有的多年同期红外遥感资料建立研究区的两个基准场,即异常识别基准场和异常提取基准场.文中设计了异常分析技术流程,提出了异常识别方法和异常定量提取模型.并以1998年张北Ms6.2地震为例,采用1995-1998年的90景NOAA/AVHRR影像进行了应用实验和对比分析,结果表明IAARF技术是有效的,可望用于卫星红外遥感异常的日常监测与分析预警工作中.  相似文献   

3.
高光谱遥感作为20世纪空间对地观测技术重大进步的产物,通过其较高的光谱分辨率,为人们提供了丰富的地球表面信息,在各个研究领域得到了快速发展和广泛应用,并取得了卓越的成果。尽管高光谱遥感具有独特的优势,但是针对其在震害评估领域中应用的相关研究较少。本文在总结高光谱遥感的特征、优势及不同领域应用现状的基础上,开展了其在震害评估领域的应用研究。基于ASD地物波谱仪获取的建(构)筑物光谱曲线构建可用于震害分析所需的光谱特征库,对比光谱库中地物曲线之间的差异后,发现高光谱遥感在震害评估领域中的应用是可行的,因不同震害地物之间的光谱特征曲线存在差异,依据这种差异可区分不同的震害信息,从而对震害遥感图像进行精细分类。  相似文献   

4.
韩召华 《地震工程学报》2020,42(2):552-557,578
利用GIS技术对地震危险等级进行评定时,由于其地形控制点选取合理性较差,导致其所采集遥感图像清晰度较低,地震等级评定不够精准。针对此问题提出一种新的地震灾情遥感信息危险等级在线应急评定方法。利用图像几何校正法,对遥感图像进行分幅裁剪,基于裁剪结果选取地面控制点,提取有价值遥感数据信息,建立遥感解译评估指标。将推导出的综合震灾指数引入到指标中,将各个评价单元的信息进行等级排序和划分,完成地震灾情遥感信息危险等级在线应急评定。仿真实验中,对所提方法和GIS地震危险等级评定方法进行有效性对比测试。实验结果表明,地震灾情遥感信息危险等级在线应急评定方法提升了灾情地形控制点选取的合理性,使获取的遥感图像更清晰,灾情等级评定结果更精准。  相似文献   

5.
张克诚  王晓青  丁香 《中国地震》2023,39(2):367-376
2015年4月25日在尼泊尔廓尔喀县发生的8.1级地震及后续强烈余震,造成尼泊尔北部严重的人员伤亡和财产损失,灾区建筑物倒塌损失严重。本文利用现场震害调查资料和高分卫星遥感影像,开展建筑物震害遥感解译,得到各个遥感解译点的遥感震害指数,结合现场调查点评估的烈度拟合了遥感震害指数-实际震害指数转换关系,再根据遥感震害指数估计了全部解译点的震害指数及地震烈度。估计的烈度与现场调查结果对比显示出较好的一致性,研究结果为该地区今后发生地震提供了可借鉴的遥感评估震害指数转换模型。  相似文献   

6.
汶川8.0级大地震应急遥感震害评估研究   总被引:6,自引:5,他引:6  
破坏性地震发生之后,在缺乏足够地面震害调查资料的情况下,通过遥感手段获取灾区震后遥感影像,图像快速处理和震害信息提取,对地震灾害及其损失进行快速评估,将弥补地面调查的不足,为地震应急指挥和救援决策提供重要依据。本文叙述了遥感应急震害评估的基本方法和该方法在2008年汶川8.0级大地震中的应用,并对实际评估效果进行了评价。  相似文献   

7.
An integrated approach [field, Interferometric Synthetic Aperture Radar (InSAR), hydrogeology, geodesy, and spatial analysis] was adopted to identify the nature, intensity, and spatial distribution of deformational features (sinkholes, fissures, differential settling) reported over fossil aquifers in arid lands, their controlling factors, and possible remedies. The Lower Mega Aquifer System (area 2 × 106 km2) in central and northern Arabia was used as a test site. Findings suggest that excessive groundwater extraction from the fossil aquifer is the main cause of deformation: (1) deformational features correlated spatially and/or temporally with increased agricultural development and groundwater extraction, and with a decline in water levels and groundwater storage (? 3.7 ± 0.6 km3/year); (2) earthquake events (years 1985–2016; magnitude 1–5) are largely (65% of reported earthquakes) shallow (1–5 km) and increased from 1 event/year in the early 1980s (extraction 1 km3/year), up to 13 events/year in the 1990s (average annual extraction > 6.4 km3). Results indicate that faults played a role in localizing deformation given that deformational sites and InSAR-based high subsidence rates (? 4 to ? 15 mm/year) were largely found within, but not outside of, NW–SE-trending grabens bound by the Kahf fault system. Findings from the analysis of Gravity Recovery and Climate Experiment solutions indicate that sustainable extraction could be attained if groundwater extraction was reduced by 3.5–4 km3/year. This study provides replicable and cost-effective methodologies for optimum utilization of fossil aquifers and for minimizing deformation associated with their use.  相似文献   

8.
The fast processing, seismic damage data extraction and loss evaluation from RS imagery acquired immediately after a destructive earthquake occurs, are important means for compen-sating the insufficiency of seismic damage information from ground-based investigations and provide an important basis for emergency command and rescue. The paper introduces the method of emergency seismic damage assessment using remote sensing data and its application to the great Wenchuan earthquake of magnitude 8.0 occurring in southwest Sichuan Province on May 12, 2008. The practical effectiveness of the method is also evaluated in the paper.  相似文献   

9.
为了弥补现有地铁火灾风险评估方法的不足,并为地铁的消防设计与管理提供量化指标,建立了以层次分析法(AHP)、专家调查法为基础,以可拓法为核心的地铁火灾风险的多级可拓评估方法,并给出了评估流程。对一地铁算例进行了评估,并根据评估结果得到地铁火灾风险的薄弱环节及管理重点。通过对比分析可知,本文方法与模糊评估方法所得的评估结果一致,从而表明:将可拓原理应用到地铁火灾风险性的评估中是合理可行的,很好地解决了地铁火灾风险评估的实际问题,本文方法可应用到相关的风险评估领域中。最后,对地铁火灾安全提出了一些建议。  相似文献   

10.
地球等离子体层位于地球电离层以上,延伸至4~6地球半径范围的环状等离子体区域,它在空间分布上与地球辐射带、环电流区域重合,是地球内磁层研究的重要内容。本文综述了地球等离子体层遥测技术的原理、发展,并总结和分析了EUV-CT的现有成果。   相似文献   

11.
中国遥感的回顾与展望   总被引:3,自引:2,他引:3  
概要地回顾了我国自上世纪50年代以来的遥感研究,主要讨论近二十年来的遥感发展进程,并对新世纪我国遥感发展作出展望。  相似文献   

12.
为实现地震应急期间非常规手段获取的遥感影像的快速定位, 提出了建立序列影像航线方程实现影像快速定位的思路和方法, 开发了影像快速自动定位程序。 以玉树地震应急期间获取的多景无地理参考信息的高分辨率航空遥感影像为实验对象, 在人工交互方式对初始影像进行粗定位的基础上, 利用本方法实现了系列影像的快速定位。 通过随机抽样点验证定位精度, 二次函数相对于一次函数拟合精度较好, 表明在损失一定精度的同时可大大提高影像快速定位的效率, 满足地震应急的需求。  相似文献   

13.
在地震灾情快速评估中,基于空间分布的高精度房屋和人口数据是最重要的两组数据,其直接决定着灾情快速评估结果的准确性以及现场重点救援的目标指向。然而,高精度房屋数据的获取一直是一个难题,由于受到诸多因素的制约,至今缺少好的解决途径,这也是导致当前灾情快速评估准确性不高的主要原因之一。本文基于遥感影像和实地调查相结合,构建较高精度的房屋基础信息,更好地反映房屋和人口的实际分布情况,为提高地震灾害损失快速评估的精度和准确性奠定必要的基础。  相似文献   

14.
Evapotranspiration (ET) is the largest term after precipitation in terrestrial water budgets. Accurate estimates of ET are needed for numerous agricultural and natural resource management tasks and to project changes in hydrological cycles due to potential climate change. We explore recent methods that combine vegetation indices (VI) from satellites with ground measurements of actual ET (ETa) and meteorological data to project ETa over a wide range of biome types and scales of measurement, from local to global estimates. The majority of these use time-series imagery from the Moderate Resolution Imaging Spectrometer on the Terra satellite to project ET over seasons and years. The review explores the theoretical basis for the methods, the types of ancillary data needed, and their accuracy and limitations. Coefficients of determination between modeled ETa and measured ETa are in the range of 0.45–0.95, and root mean square errors are in the range of 10–30% of mean ETa values across biomes, similar to methods that use thermal infrared bands to estimate ETa and within the range of accuracy of the ground measurements by which they are calibrated or validated. The advent of frequent-return satellites such as Terra and planed replacement platforms, and the increasing number of moisture and carbon flux tower sites over the globe, have made these methods feasible. Examples of operational algorithms for ET in agricultural and natural ecosystems are presented. The goal of the review is to enable potential end-users from different disciplines to adapt these methods to new applications that require spatially-distributed ET estimates.  相似文献   

15.
Two colour laser ranging to artificial satellites is an attractivetechnique, which is capable to provide refraction corrected ranges without the need of an atmospheric model by measuring the dispersive delay of laser pulses of different wavelength. Although the required accuracy of the detection scheme is stringent, the technique has matured so far, that routine two colour observationsbecame feasible.The present paper describes a normal point procedure reducing two colour laser range observations with respect to the dispersive delay,exploiting the knowledge of satellite response signatures in conjunction with detector characteristics and the appropriate center of mass correction models.Moreover the dispersion model of the atmosphere is briefly reviewed, paying attention to the wavelength domains provided by modern twocolour ranging lasers, e.g., the Ti:SAP laser.Preliminary data is presented and compared to both, normal point data reduced with a standard procedure and zenith path equivalent meteorological parameters.  相似文献   

16.
太湖水中光辐射传输的数值模拟   总被引:2,自引:0,他引:2  
水体的初级张产力状況在很大程度上取决于水沐光学状況,与透光层深度Zeu密切联系。Zeu这类表观光学属性取决于光辐射在水中的传输状况,最终取决丁水体:本身的微 物邢汴质如吸收和散射等。本文根椐太湖悬浮质的实测资料计界所得的水体固有光学参位,利用数值模拟的方法研悬浮质浓度垂直梯变的太湖水体中光辐射的传输情況并讨论了诸因子的影响。  相似文献   

17.
The term ``Geographic Information System (GIS) appeared in the 1960'sas a result of the extension of database systems to all types of geographic data.GIS is a decision-making tool which provides geographic knowledge. Itrepresents a rapidly expanding field which covers various disciplines suchas cartography, geography, statistics, remote sensing and other disciplinesdealing with the analysis of located data. A large number of GIS applicationsinvolve all types and all scales of spatial management (urban planning,environment, etc.). Its use with spaceborne Earth observation data isintroduced here.  相似文献   

18.
卫星遥感热红外辐射观测可给出连续可靠的全球地气热场变化的信息,监测方法和观测结果都具有十分明确的物理意义。将其应用于地震监测预报领域的研究和实践都已取得了一些进展,具有良好的发展前景。  相似文献   

19.
本文对玉树地震前后的热异常多参量变化进行分析研究,主要包括长波辐射(Outgoing Longwave Radiation),地表温度(Land Surface Temperature),NCEP地面气温(National Center for Environmental Prediction)和地下水温。研究结果证实玉树地震前确实存在热异常现象。在多参量中,地下水温最早出现异常并且异常持续时间最长;其次出现热异常的是反映地表介质辐射属性的长波辐射;地表温度出现热异常的时间要晚于长波辐射;NCEP地面温度反映了一定垂直厚度的平均大气温度,因此最晚出现热异常现象。同时,玉树地震前的多参量热异常区域都位于震中南部或西南部。  相似文献   

20.
Boosting is a classification method which has been proven useful in non-satellite image processing while it is still new to satellite remote sensing. It is a meta-algorithm, which builds a strong classifier from many weak ones in iterative way. We adapt the AdaBoost.M1 boosting algorithm in a new land cover classification scenario based on utilization of very simple threshold classifiers employing spectral and contextual information. Thresholds for the classifiers are automatically calculated adaptively to data statistics.The proposed method is employed for the exemplary problem of artificial area identification. Classification of IKONOS multispectral data results in short computational time and overall accuracy of 94.4% comparing to 94.0% obtained by using AdaBoost.M1 with trees and 93.8% achieved using Random Forest. The influence of a manipulation of the final threshold of the strong classifier on classification results is reported.  相似文献   

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