共查询到18条相似文献，搜索用时 234 毫秒
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针对GLAS地学激光测高系统是冰、云和陆地高程卫星(ICESat)的唯一监测工具,能够记录地表光斑内的地物信息,是否能应用于黄土高原土地覆盖分类的问题进行了研究。利用粒子群和最小二乘法相结合的方法对GLAS波形数据进行高斯分解,获取高斯波个数、波形总能量、波形信号起始和信号结束位置4个波形参数;基于波形自动分类方法对黄土高原水体、森林、城市用地、其他地类(裸地、低矮植被等)进行分类。通过基于覆盖相同研究区域的30 m地表覆盖数据(Globe Land30),验证分类的准确性。结果表明,GLAS大光斑波形数据对黄土高原的4种地类能够很好地进行区分,总分类精度高达87.68%,Kappa系数为65.79%。研究表明,GLAS波形数据可以作为获取土地覆盖信息的有效数据源,为研究黄土高原土地覆盖变化提供更丰富的数据支持。 相似文献
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《武汉大学学报(信息科学版)》2016,(8)
南极查尔斯王子山脉实地科学考察的顺利开展需要该区域1∶50 000基础地理信息数据作为支撑。国产高分辨率资源三号立体影像为基础地理信息数据的获取提供了必要的遥感数据支持。充分利用资源三号立体数据,在冰、云和陆地高程卫星(the ice,cloud,and land elevation satellite,ICESat)上的地学激光测高系统(Geoscience Laser Altimeter System,GLAS)等多源遥感信息的辅助下,制作了南极查尔斯王子山脉1∶50 000基础地理信息成果,并对其进行了精度分析。分析结果表明,数字高程模型(DEM)的高程精度优于5.31m,数字正射影像图(DOM)成果与南极洲陆地卫星影像镶嵌图比较的较差中误差为16.30m。因此,在南极地区利用资源三号立体数据集成各种遥感数据制作1∶50 000基础地理信息成果是高效实用的。 相似文献
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复杂海域ERS-1卫星测高波形的波形分类方法研究 总被引：1，自引：0，他引：1
分析表明海域的两类基本波形类型为镜面和散射波形,提出了波形移动相关分析,用于复杂海域波形分类。在近海和南极海域实验区,对ERS-1回波信号波形分类。结果表明,脉冲峰值、-β5和波形移动相关分析均可进行波形分类。 相似文献
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李阿竹 《测绘与空间地理信息》2017,(1)
论述了在朝阳地区地理国情普查任务中,地表覆盖分类数据生产内业的主要流程及技术方法。结合实际作业对地表覆盖分类数据的相关精度要求、采集原则和标准以及编辑的技术手段做出了较为详细的说明,提出了采编过程中影响成果精度的关键问题处理办法,为地理国情普查工作的顺利进行起到了指导作用。 相似文献
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介绍了遥感传感器技术的发展,着重探讨了其在观察极地地区进行观测的适用性。极地地区与全球气候变化之间的关系和相互作用是气候变化研究的焦点。海冰的广泛覆盖对大气、海洋和极地地区特别是对其他地方的、其他进程的陆地和海洋生态系统产生重大影响。海冰覆盖了极地海洋广阔的区域,而两极地区的海冰受气候变化影响而产生的变化却不同,北极海冰面积减少趋势明显而南极海冰面积却有上升趋势。本研究回顾了海冰遥感领域的相关文献,评估不同传感器监测海冰物理特性的优势和劣势。分析了传感器的规格和获取的数据,概括了它们如何发展以满足用户不断增长的需求。同时,讨论了不同的遥感技术和观测方法及其在监测海冰变化方面的适用性。本文利用不同的数据集对海冰特性进行进一步的研究,总结了用于海冰监测的数据集以监测这些实地很难到达的区域。 相似文献
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通过对基于Geoway组合软件的两套方案开展地理国情普查地表分类信息提取方法试验,对比两套方案的适用性,研究地表分类信息的关键技术,总结应用软件在地表分类信息提取的方法和步骤,为后续开展地理国情监测中的地表覆盖分类信息提取提供技术参考。 相似文献
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The Geoscience Laser Altimeter System (GLAS) aboard Ice, Cloud and land Elevation Satellite (ICESat) is a spaceborne LiDAR sensor. It is the first LiDAR instrument which can digitize the backscattered waveform and offer near global coverage. Among others, scientific objectives of the mission include precise measurement of vegetation canopy heights. Existing approaches of waveform processing for canopy height estimation suggest Gaussian decomposition of the waveform which has the limitation to properly characterize significant peaks and results in discrepant information. Moreover, in most cases, Digital Terrain Models (DTMs) are required for canopy height estimation. This paper presents a new automated method of GLAS waveform processing for extracting vegetation canopy height in the absence of a DTM. Canopy heights retrieved from GLAS waveforms were validated with field measured heights. The newly proposed method was able to explain 79% of variation in canopy heights with an RMSE of 3.18 m, in the study area. The unexplained variation in canopy heights retrieved from GLAS data can be due to errors introduced by footprint eccentricity, decay of energy between emitted and received signals, uncertainty in the field measurements and limited number of sampled footprints.Results achieved with the newly proposed method were encouraging and demonstrated its potential of processing full-waveform LiDAR data for estimating forest canopy height. The study also had implications on future full-waveform spaceborne missions and their utility in vegetation studies. 相似文献
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中国南方森林冠顶高度Lidar反演—以江西省为例 总被引：1，自引：0，他引：1
激光雷达(Lidar)与光学遥感的有效结合对中国南方区域森林冠顶高度反演意义重大,而国产卫星将为中国森林生态研究提供新的数据源。本文联合利用大脚印激光雷达GLA和国产MERSI数据,在实现GLAS波形数据处理和不同地形条件下森林冠顶高度反演算法基础上,建立了区域尺度不同森林类型林分冠顶高度GLAS+MERSI联合反演关系模型,进行了江西地区森林冠顶高度反演。总体上,GLAS激光雷达森林冠顶高度估算精度较高;且在与MERSI 250 m数据的联合反演模型中,针叶林模型精度较好(R2=0.7325);阔叶林次之(R2=0.6095);混交林较差(R2=0.4068)。分析发现,考虑了光学遥感生物物理参数的GLAS+MERSI联合关系模型在区域森林冠顶高度估算中有较高精度,且在空间分布上与土地覆盖数据分布特征非常一致。 相似文献
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S. Ghosh S. Nandy S. Patra S. P. S. Kushwaha A. Senthil Kumar V. K. Dadhwal 《Journal of the Indian Society of Remote Sensing》2017,45(2):327-335
In the present study, parameters derived from Ice, Cloud, and land Elevation Satellite/Geoscience Laser Altimeter System (GLAS) full waveform were used for land cover classification in western part of Doon valley, Uttarakhand, India. Three parameters, viz, height, front slope angle (afslope) and canopy return ratio (rCanopy) were extracted from the returned full waveform signals. k-means (KM), partitioning around medoids (PAM), and fuzzy c-means (FCM) with different cluster sizes were used for classifying the land cover types with the help of GLAS-derived parameters. Among the clustering methods, KM performed the best. The overall accuracy (89.41 %) of all methods were quite significant with cluster size three i.e. with three classes forest, mango orchard and other class including agriculture, barren/fallow land, settlement, dry river bed, etc. The accuracy of the PAM (60 %) and the FCM (68.4 %) decreased drastically at four clusters with the separation of agriculture from barren/fallow land. The accuracy of the PAM and the FCM further decreased with increase in the number of clusters whereas KM showed reliable results for all clusters. KM with five clusters was able to distinguish five different land covers, viz, forest, mango orchard, agriculture and barren/fallow land and other class including settlement, dry river bed, etc. with an overall classification accuracy of 72.93 %. The study presents a method for classifying land cover types using GLAS full waveform data. 相似文献
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激光测高仪回波波形饱和现象客观存在,为增加可用激光点数目、提高饱和波形测高精度,本文提出了一种波形饱和识别与测高误差改正方法,首先,利用回波波形峰度系数对饱和波形进行识别,然后,针对饱和现象对波形高斯拟合的影响,计算高斯拟合波形与原始波形相交区域的形心位置,以形心位置差异确定因波形饱和导致的测高误差并改正。最后,采用ICESat/GLAS（Ice,Cloud and land Elevation Satellite/Geo-science Laser Altimeter System）在青海湖、纳木错、色林错采集的波形数据进行实验。结果表明,经本文算法改正后数据误差均值为0.03 m,大型湖泊区域可实现约0.05 m的测高精度,结合峰度的饱和识别方法可以对波形进行有效筛选,可发现GLAS遗漏的饱和波形,饱和改正算法可以有效改正波形饱和引起的测高误差,改正后精度明显优于GLAS提供的饱和改正结果,相关结论对高分七号卫星激光波形处理有一定参考价值。 相似文献
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介绍地学激光测高系统（ICESAT／GLAS）基本原理和ICESAT／GLAS的数据产品,对其中包含的误差和应采用的改正模型进行分析。并对冰盖、海冰、陆地以及海面等不同地表特征下波形的处理算法进行研究,包括表面特征参数的提取算法,如表面倾斜度算法。同时,研究脚点的定位算法。 相似文献
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Detailed forest height data are an indispensable prerequisite for many forestry and earth science applications. Existing research of using Geoscience Laser Altimeter System (GLAS) data mainly focuses on deriving average or maximum tree heights within a GLAS footprint, i.e. an ellipse with a diameter of 65 m. However, in most forests, it is likely that the tree heights within such ellipse are heterogeneous. Therefore, it is desired to uncover detailed tree height variation within a GLAS footprint. To the best of our knowledge, no such methods have been reported as of now. In this study, we aim to characterize tree heights’ variation within a GLAS footprint as different layers, each of which corresponds to trees with similar heights. As such, we developed a new method that embraces two steps: first, a refined Levenberg–Marquardt (LM) algorithm is proposed to decompose raw GLAS waveform into multiple Gaussian signals, within which it is hypothesized that each vegetation signal corresponds to a particular tree height layer. Second, for each layer, three parameters were first defined: Canopy Top Height (CTH), Crown Length (CL), and Cover Proportion (CP). Then we extracted the three parameters from each Gaussian signal through a defined model. In order to test our developed method, we set up a study site in Ejina, China where the dominant specie is Populus euphratica. Both simulated and field tree height data were adopted. With regard to the simulation data, results presented a very high agreement for the three predefined parameters between our results and simulation data. When our methods were applied to the field data, the respective R2 become 0.78 (CTH), CL (R2 = 0.76), CP (R2 = 0.74). Overall, our studies revealed that large footprint GLAS waveform data have the potentials for obtaining detailed forest height variation. 相似文献
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针对大光斑激光雷达回波信号噪声影响森林冠顶高估测精度,且回波分析法判定回波位置受限于平坦地区的问题,利用高斯低通滤波和小波去噪两种方法对GLAS波形进行去噪处理,提出了结合均方根倍差法和回波分析法来判定回波位置的有效算法。经小波去噪后信号的信噪比23.360 704,均方根误差为0.000 233 3,经均方根倍差法和回波分析法相结合来判定回波位置估测的冠顶高结果与实测结果相关性系数r值为0.864,效果均优于高斯低通滤波去噪。基于GLAS回波数据实验结果表明:小波去噪较好地实现了对回波信号的去噪处理,均方根倍差法和回波分析法相结合,实现了对坡度相对较大地区的GLAS波形的回波开始位置和地面回波位置的准确判定,对森林冠顶高的精确估算具有重要意义。 相似文献
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遥感技术是研究土地利用/覆被变化状况的重要手段之一,目前该技术已有一套较成熟的研究方法,本文从遥感数据选择、图像预处理方法、土地利用/覆被变化遥感分类、土地利用/覆被变化动态信息提取等方面对土地利用/覆被变化遥感动态监测技术进行了系统的论述,最后指出多信息源、综合的信息处理机制将是土地利用/覆被变化遥感动态监测技术发展的必然方向。 相似文献