共查询到20条相似文献，搜索用时 250 毫秒
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张峰 《测绘与空间地理信息》2017,40(11)
针对辽西北中轻度沙化土地的区域特点和特殊性,通过分析其沙化土地的光谱特征、空间分布及时间变迁特征,研究了一种时空约束下的多光谱遥感影像沙化土地识别方法。在对沙化土地进行光谱特征分析的基础上,加入时-空分布特征进行约束修正,有效提高了沙化土地监测的精度和效率。 相似文献
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利用1975年MSS、2000年ETM+和2007年CBERS-02B共3期影像数据开展三江源地区土地沙化遥感调查监测,在此基础上重点分析了32 a来三江源地区土地沙化时空变化特征及其驱动力因素。三江源土地沙化总体表现为先增加后减少的过程,沙化土地主要分布于海拔相对较高的平缓高原面上的盆地内,且具有沿河、沿交通线分布的特点。2000年以前,气候暖干化和人为活动加剧造成了土地沙化日益严重,表现为总量在增加、程度在加重、空间分布变化频繁;2000年以后,气候暖湿化是土地沙化趋于改善的最主要因素。 相似文献
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基于高光谱遥感技术的土地质量信息挖掘研究 总被引：17，自引：1，他引：17
土地资源的高效管理对土地资源与生态环境监测提出更高的要求,高光谱遥感图像精细的光谱线可提高土地动态监测的精度、广度和深度,在土地资源与土地质量监测中具有广阔的应用前景。本文基于高光谱遥感技术,详细探讨了土地质量指标,主要是土壤有机质土壤水分信息提取的技术流程和关键技术。通过地物光谱分析认为,有机质含量越高的土壤,其光谱发射率越低;重度沙化土地实验室光谱曲线光谱反射率最高,依次排序为中度沙化、轻度沙化和无退化土地;重度水蚀土地光谱反射率较高,但中度水蚀土地与轻度水蚀和无退化土地实验室光谱曲线无明显差异。在光谱分析基础上,利用多元统计分析技术建立了土壤光谱在677、1202、2074和1509nm四个波段的有机质反演模型和在1423、1524、1746nm三个波段的预测土壤含水量的回归模型;并将有机质反演模型应用于宜兴成像光谱遥感数据中,进行宜兴试验区土壤有机质参数成图。最后探讨了反演模型应用推广所存在的问题。 相似文献
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随着社会的高速发展,资源与环境问题日益显著,土地利用/覆被变化(Land Use and Land Cover Change,LUCC)的研究日益成为全球范围内的研究热点。本文基于辽宁省朝阳市6期LandsatTM影像,以ENVI 4.5和ArcGIS为图像处理平台,采用决策树分类方法,将朝阳市土地利用类型分为耕地、林地、水域、建设用地、未利用地五大类,通过对比多期朝阳市土地利用的变化情况,分析研究区土地利用/覆被动态的内在变化规律,进而综合评价朝阳市土地利用效率及各类土地利用转化情况。 相似文献
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结合实际工作,以天绘影像(天绘一号遥感影像)为基础,结合GIS空间分析以及GPS外业调查技术,依据国家林业局《全国荒漠化和沙化监测技术规定》对鄂尔多斯杭锦旗荒漠化土地进行了监测评价,形成了杭锦旗全旗的正射影像图、荒漠化土地类型程度分布图。文章阐述了天绘影像的处理方法,3S技术在荒漠化土地监测中的具体应用分析方法,总结了整体荒漠化土地遥感监测的流程,供同行业开展此类工作参考。 相似文献
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采用Landsat TM数据分析了阿克苏河—塔里木河断面水质污染状况,通过波段的DN值和常规监测数据建立能反映水质状况的
污染物监测模型。结果发现,将2000年常规监测数据代入模型后,与遥感数据的结果基本吻合| 重建阿克苏河—塔里木河的连续水体
污染变化曲线,得出污染物浓度随着远离上游而增加。 相似文献
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Monitoring drought dynamics in the Aravalli region (India) using different indices based on ground and remote sensing data 总被引：5，自引：0，他引：5
C. Bhuiyan R.P. Singh F.N. Kogan 《International Journal of Applied Earth Observation and Geoinformation》2006,8(4):289-302
The hard-rock hilly Aravalli terrain of Rajasthan province of India suffers with frequent drought due to poor and delayed monsoon, abnormally high summer-temperature and insufficient water resources. In the present study, detailed analysis of meteorological and hydrological data of the Aravalli region has been carried out for the years 1984–2003. Standardised Precipitation Index (SPI) has been used to quantify the precipitation deficit. Standardised Water-Level Index (SWI) has been developed to assess ground-water recharge-deficit. Vegetative drought indices like Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) and Vegetation Health Index (VHI) have been computed using NDVI values obtained from Global Vegetation Index (GVI) and thermal channel data of NOAA AVHRR satellite. Detailed analyses of spatial and temporal drought dynamics during monsoon and non-monsoon seasons have been carried out through drought index maps generated in Geographic Information Systems (GIS) environment. Analysis and interpretation of these maps reveal that negative SPI anomalies not always correspond to drought. In the Aravalli region, aquifer-stress shifts its position time to time, and in certain pockets it is more frequent. In comparison to hydrological stress, vegetative stress in the Aravalli region is found to be slower to begin but quicker to withdraw. 相似文献
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Piyoosh Rautela Ramesh Chandra Lakhera 《International Journal of Applied Earth Observation and Geoinformation》2000,2(3-4)
The area around Sataun in the Sirmur district of Himachal Pradesh, India (falling between the rivers Giri and Tons; both tributaries of the Yamuna River) was studied for landslide vulnerability on behalf of the inhabitants. The study was made using extensive remote sensing data (satellite and airborne). It is well supported by field evidence, demographic and infrastructural details and aided by Geographic Information System (GIS) based techniques. Field observations testify that slope, aspect, geology, tectonic planes, drainage, and land use all influence landslides in the region. These parameters were taken into consideration using the statistical approach of landslide hazard zonation. Using the census data of 1991, vulnerability of the populace to the landslide hazard was accessed. As most of the infrastructure in the region is concentrated around population centres, population data alone was used for vulnerability studies. 相似文献
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ZHAN F. Benjamin 《地球空间信息科学学报》2011,(1)
Although it is well known that coseismic gravity changes take place during an earthquake, previous research has not yielded convincing evidence demonstrating that significant gravity changes occur before large earthquakes. Furthermore, even if we suspect that gravity changes occur before large earthquakes, we have yet to demonstrate how to consistently observe these changes for useful earthquake forecast that would bring benefits to society. We analyzed ground gravity survey data obtained in 1998, 2000, 200... 相似文献
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GNSS系统及其技术的发展研究 总被引：3，自引：1，他引：2
阐述了国际上卫星导航系统的总体发展,对美、俄、欧、中的四大全球系统,以及相关的区域系统和增强系统进行了简单的介绍,研究分析了GNSS系统及其技术的发展趋势,同时分析了我国Compass全球系统面临的机遇和挑战,并提出了我国未来工作的建议. 相似文献
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“4D”技术及其应用 总被引：13，自引：0，他引：13
介绍“４Ｄ”（即数字地面模型、数字正射影像、数字栅格地图和数字线划地图）系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。 相似文献
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《International Journal of Digital Earth》2013,6(1):66-87
Abstract Virtual Australia is not a well-defined or agreed concept. This discussion paper conceptualises Virtual Australia as a ‘virtual [digital] model containing and representing all non-trivial objects and their contextual environment – from blue sky to bedrock – in real world Australia’. It describes a scenario for Virtual Australia, one or two decades from now, in which the locations and conditions of non-trivial objects and their environment are updated automatically through a combination of remote sensing and wireless communication technologies in support of a ‘Supranet’. It then examines the concept of the ‘Supranet’ – a pervasive information network based largely on wireless technology linking the physical world to a virtual model in real time – and develops and discusses three principal characteristics of the Supranet: the ability to have or collect specific information (know); the ability to process information (think); and the ability to communicate that information. If, in the near future, any or all non-trivial devices are to some extent able to know, think and communicate, the potential for object autonomy will be realised. 相似文献
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自动车辆定位导航系统中传感器的误差分析 总被引：1，自引：0，他引：1
对国界定位导航系统中几种常见的辅助传感器所产生的误差进行了分析，导出了不同传感器的误差模型。这些误差模型是估计车辆位置的扩展卡尔曼滤波器的基础，同时也为选择适当的传感器提供了理论根据。 相似文献