共查询到19条相似文献，搜索用时 375 毫秒
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利用ArcGIS对矢量、栅格数据的处理功能和开放式的开发功能实现图像自动分幅.地形图是采用经纬网梯形分幅法,据此可以在ArcGIS中生成图幅的矢量图,并把新旧图幅号作为矢量的属性.通过选取图像覆盖范围内的分幅矢量获取图幅范围,应用ArcObject提供的栅格数据处理方法提取遥感图像的子图,以图幅号为文件名存放.对分幅功能实现的算法进行了详细描述,对关键的数据类型作了说明. 相似文献
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<正> 造林像许多林业活动一样,与所用的方法有关,要几年甚至十年才有结果。另外,这些活动分散在相当大的范岡内淙蛔?930年以来航空像片已被广泛地使用,事实上为了处理目前和将来资料的需要都在应用航空像片。使用历史上的航空像片结合现存林分资料去跟踪原始的或次生的林分,包括过去的造林措施,既能更好的发展也能较好的应用。为了监督造林的技术,航空像片对林地经营者来说具有独一无二的优点,因为它提供了广阔的植被覆盖与短暂的收获作物情况(历史上的和将来的)。 相似文献
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面向对象的GEO遥感影像分类与信息提取 总被引：1，自引：0，他引：1
对GEO卫星遥感数据的特性进行了评价,并在envi zoom软件中采用边缘分割算法进行影像分割,获取影像对象,综合运用对象的光谱、空间特征和纹理特征,提取了张家界森林公园研究区域内土地覆盖与土地利用信息,对基于像素的最大似然法与这种基于对象的分类方法进行了对比分析,结果表明:基于对象分类方法,能很好地利用高分辨率卫星图... 相似文献
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在森林资源二类调查中,以往是采用航空像片(以下称航片)和地面调查相结合的方法,所用航片成本高、时相差,地面调查工作强度大且耗时长,很难满足建立数字林业的需要.很显然,现在使用卫星像片(以下称卫片)要好于航片,但采用高分辨率的卫片所需总成本也较高,用户也要考虑性价比和成本,对于分辨率不高的卫片,总想设法利用现有条件获得一个好的解译效果,已获得广泛采用的图象融合技术即可部分地解决这一问题.现利用美国陆地卫星TM和法国地球探测卫星SPOT两种影像,选取适合森林分类的波段组合和融合技术,并借助于地理信息系统(GIS)对分类结果进行评价. 相似文献
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高分辨率遥感图像均值调整法分割技术研究 总被引：1，自引：1，他引：1
遥感图像分割是将以像元为基础的图像转化为以对象为基础的过程,因此,遥感图像分割是遥感图像高级分析的基础.对于中、低分辨率遥感图像来说,单个像元的面积较大,且混合像元现象严重,图像分割会产生较大的误差.高分辨率遥感图像单个像元的面积较小,分割后图像上单个对象内含若干像元,便于分析和提取信息.以高分辨率遥感图像Q u ickB ird和IKONO S为研究对象,采用均值调整法对图像进行分割和精度检验.结果表明:采用均值调整法进行高分辨率遥感图像分割具有较好的效果,图像分割的速度和精度均较高. 相似文献
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有关林木株数的统计估值,国内外多采用实地抽样调查法。但遥感技术在林木勘察设计方面的应用,在各国已越来越受到重视。在实践中我们发现,由于受地面分辨率的限制,单纯运用卫星像片是不适宜作林木株数的定量分析的。航空遥感像片虽然具有象质清晰、高分辨率等长处,但在森林稠密的区域中,由于树冠相互重叠覆盖,同样造成了目视判读林木株数的困难。所以,要利用航片 相似文献
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三江并流世界自然遗产地的遥感分析 总被引：3，自引：0，他引：3
从陆地卫星TMD131/41图像上可以看出,三江(怒江、澜沧江和金沙江)并流的真面目。通过遥感判读、利用判读的野外概率抽样和GIS处理技术,对三江并流进行地理景观分析。该三江并流地具有地质地貌的独特性、生态系统的完整性、生物资源的多样性和自然景观的奇特性。通过对三江并流自然遗产的分析得知森林植被是生态、景观和生物多样性保护的基础。此外,科学管理也是遗产保护的重要措施。 相似文献
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遥感估测森林可燃物载量的研究进展 总被引：3，自引：1，他引：3
对采用遥感图像估测森林可燃物载量的方法进行综述.首先将现有方法根据对像元载量的分配方法,分成直接分配法和间接分配法2种.直接分配法分成聚类分析法和判别分析法;间接分配法分为简单植被特征法、林分模型法和综合因子约束法3种.然后对各方法的优缺点进行评价,指出现有方法整体准确率不高的不足,并分析产生误差的3个来源:1) 从遥感图像判读中间特征所产生的误差;2) 从中间特征到可燃物载量之间的误差;3) 使用可燃物模型所产生的误差.据此提出改进现有方法、提高估测准确率的3个思路:1) 使用新图像,如更高分辨率遥感图像、雷达图像或混合图像;2) 选择更合适的中间特征以及它们与可燃物载量的关系模型;3) 使用连续变量来描述可燃物载量. 相似文献
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Process-based approach to automated classification of forest structures using medium format digital aerial photos and ancillary GIS information 总被引：1，自引：0，他引：1
Filip Hájek 《European Journal of Forest Research》2008,127(2):115-124
The methods of forest inventory data acquisition, based on the analysis of remotely sensed images have been well tested and
implemented during the last decade. The predominant visual interpretation and pixel-based automated techniques are now being
gradually replaced by the object-based image classification at multiple levels. This paper describes an experiment using medium-format
digital aerial imagery for the purpose of automated updating of the existing GIS forest management database (LHPO). The method
emphasises the pre-processing phase, where various image transforms and additional channels i.e. spectral ratios and vegetation
indices (NDVI), low-pass filters, Sobel edge and GLCM (grey level co-occurrence matrix) texture measures are derived from
the original dataset. The layer stack is then transferred into the object-oriented classification environment together with
the existing thematic vector layer, and analysed on three hierarchical object levels. The classification involves the recognition
of the successional stage of forest compartments and the estimation of tree species composition in terms of area coverage.
In addition, age information on the GIS forestry management map can be updated and the spatial distribution of classes corrected
using the multi-scale object relations of the former analysis. The advances of the automated procedure based on sequential
processing of image objects are partially covered. Moreover, aspects of utilisation of the medium-format colour infra-red
images (CIR) as an alternative to traditional aerial photos and very high resolution (VHR) satellite data, were considered. 相似文献
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Following the severe drought in 1999–2000 there was a widespread outbreak of oak decline in the Ozark Highlands. Over 400,000 ha of dead and dying oak trees were observed by the USDA Forest Service in this region. Although oak forests that are dead can be easily interpreted from air photos or classified from satellite images, it is difficult to detect dying trees that are still green but will die back or recover in the following years. In this study, we applied a normalized difference water index (NDWI) to map the continuous forest dynamics related to oak decline. The Landsat TM image in 1992 and the ETM+ image in 2000 were processed to calculate the differential NDWI which revealed moisture variation primarily caused by the drought and the associated red oak borers. A simple thresholding method was used to map oak dying back, recovery and non-change areas in the study area. The died-back areas were extracted from the modified land use/land cover maps created by the Missouri Resource Assessment Partnership (MoRAP). The forest dynamics map was compared with the online FIA database in which tree species at randomly selected sites were recorded in 1989 and 2003. The overall accuracy of forest dynamics mapping with remote sensing imagery was 75.95%. The user's accuracy of dying/recovery area mapping was also high although the producer's accuracy is questionable because of the limitation in ground data collection. The continuous dying/recovery map in this study could provide valuable information on the prediction of oak decline and evaluation of damage when another period of environmental stresses occurs. 相似文献
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Zhang Li Li Li-juan Liang Li-qiao Li Jiu-yi 《中国林学(英文版)》2007,9(4):256-261
Measurement of vegetation coverage on a small scale is the foundation for the monitoring of changes in vegetation cover-age and of the inversion model of monitoring vegetation coverage on a large scale by remote sensing. Using the object-oriented ana-lytical software, Definiens Professional 5, a new method for calculating vegetation coverage based on high-resolution images (aerial photographs or near-surface photography) is proposed. Our research supplies references to remote sensing measurements of vegeta-tion coverage on a small scale and accurate fundamental data for the inversion model of vegetation coverage on a large and interme-diate scale to improve the accuracy of remote sensing monitoring of changes in vegetation coverage. 相似文献