排序方式： 共有60条查询结果，搜索用时 15 毫秒
31.
ALOS卫星遥感数据影像特征分析及应用精度评价 总被引：6，自引：0，他引：6
通过影像灰度等级分析、单变量统计分析和影像纹理特征分析以及平面点位精度、影像分类精度和图斑面积精度评定,针对ALOS数据图像质量开展影像特征研究与应用精度综合评价,并与SPOT5数据对比。ALOS数据在纹理特征及面积精度方面(尤其是较小的图斑面积精度)均明显优于SPOT5;建设用地和农用地二、三级地类的影像分类精度均可达到优良等级;点位中误差精度可满足1∶1万比例尺制图要求。ALOS数据在国土资源调查和管理中具有良好的应用前景,可与SPOT5形成较好的数据互补。 相似文献
32.
ALOS融合影像质量评价及其土地盐渍化应用研究 总被引：2，自引：1，他引：1
将经过配准的同一地区不同空间分辨率和光谱分辨率的遥感影像进行融合是提高土地覆盖/土地利用分析精度的有效途径。采用PCA、IHS、HPF和小波变换融合法对内蒙古杭锦后旗中部地区的ALOS全色和多光谱影像进行融合,并对融合结果进行了定性和定量评价。基于地物光谱特征、解译标志和监督分类法提取试验区土地盐渍化信息,比较多光谱影像和融合影像的土地盐渍化信息提取精度。结果显示,PCA、IHS和HPF融合影像的空间细节表现能力得到提升,而PCA和小波变换融合影像的光谱保真度优于IHS和HPF融合影像;PCA融合影像的盐渍化分类精度、总分类精度和Kappa系数均为最高,是最适于试验区土地盐渍化分类研究的融合方法。 相似文献
33.
Saygin Abdikan 《国际地球制图》2018,33(1):21-37
Remote sensing data utilize valuable information via various satellite sensors that have different specifications. Image fusion allows the user to combine different spatial and spectral resolutions to improve the information for purposes such as forest monitoring and land cover mapping. In this study, I assessed the contribution of dual-polarized Advanced Land Observing Satellite/Phased Array type L-band Synthetic Aperture Radar data to multispectral Landsat imagery. The research investigated the separability of forested areas using different image fusion techniques. Quality analysis of the fused images was conducted using qualitative and quantitative analyses. I applied the support vector machine image classification method for land cover mapping. Among all methods examined, the à trous wavelet transform method best differentiated the forested area with an overall accuracy (OA) of 94.316%, while Landsat had an OA of 92.626%. The findings of this study indicated that optical-SAR-fused images improve land cover classification, which results in higher quality forest inventory data and mapping. 相似文献
34.
冰川流速分析对于研究南极冰盖物质平衡、海平面上升和全球气候变化具有重要意义。以ALOS/PALSAR影像为数据源,采用SAR特征跟踪方法,结合DEM数据估算Amery冰架上游冰川流速。结果表明,Amery冰架上游主流线流速为540—720 m·a-1,冰川流速随海拔的降低逐渐减小。受基岩和两侧山体的影响,主流线流速大,越靠近两侧山体流速越小。这个结果与NASA 2000年利用SAR重复轨道干涉测量方法测定的流速接近。基于裸露岩石作为特征点的分析表明,该方法误差较小,获取的冰川流速比较可靠。 相似文献
35.
针对轨道误差和大气延迟误差是制约ALOS PALSAR数据快速获取大面积及高精度数字高程模型的主要因素这一问题,该文提出一种基于埃尔米特(Hermite)插值和高程大气模型对两种误差进行联合矫正的方法。首先,采用埃尔米特插值法对轨道矢量数据进行插值,以提高去除平地效应的效果;然后,建立高程与相位之间的线性模型,去除与高程相关的大气延迟误差;最后,进行相位高程转换得到数字高程模型。利用陕西省彬县地区的两景ALOS PALSAR数据进行实验分析。结果表明,该方法获取的数字高程模型以航天飞机雷达地形测绘使命为参考的均方根误差为14.48m,比常规干涉方法获取的结果有很大的提高,证明了该方法的有效性。 相似文献
36.
Single, interferometric dual, and quad-polarization mode data were evaluated for the characterization and classification of seven land use classes in an area with shifting cultivation practices located in the Eastern Amazon (Brazil). The Advanced Land-Observing Satellite (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) data were acquired during a six month interval. A clear-sky Landsat-5/TM image acquired at the same period was used as additional ground reference and as ancillary input data in the classification scheme. We evaluated backscattering intensity, polarimetric features, interferometric coherence and texture parameters for classification purposes using support vector machines (SVM) and feature selection. Results showed that the forest classes were characterized by low temporal backscattering intensity variability, low coherence and high entropy. Quad polarization mode performed better than dual and single polarizations but overall accuracies remain low and were affected by precipitation events on the date and prior SAR date acquisition. Misclassifications were reduced by integrating Landsat data and an overall accuracy of 85% was attained. The integration of Landsat to both quad and dual polarization modes showed similarity at the 5% significance level. SVM was not affected by SAR dimensionality and feature selection technique reveals that co-polarized channels as well as SAR derived parameters such as Alpha-Entropy decomposition were important ranked features after Landsat’ near-infrared and green bands. We show that in absence of Landsat data, polarimetric features extracted from quad-polarization L-band increase classification accuracies when compared to single and dual polarization alone. We argue that the joint analysis of SAR and their derived parameters with optical data performs even better and thus encourage the further development of joint techniques under the Reducing Emissions from Deforestation and Degradation (REDD) mechanism. 相似文献
37.
环境因子对土壤水分空间异质性的影响——以北京市怀柔区为例 总被引：1，自引：0，他引：1
为了探讨山区表层土壤水分的空间分布格局及其影响因素,以北京市怀柔区为研究区域,联合使用ALOS/PA-LSAR微波数据和Landsat-5遥感影像反演得到研究区的土壤水分数据,运用旋转主成分分析法分析了高程、坡度、坡向和植被盖度4个环境因子对土壤水分的影响情况及分布规律,并确定相应的主控因子.结果表明:高程和坡度是影响山区表层土壤水分空间变异的主控因子,植被盖度次之,坡向的影响最弱.对主控因子(高程和坡度)的单因素分析表明,土壤含水量随着高程的增加而逐渐减少,随着坡度的增加,土壤含水量总体上呈现先增加(坡度＜3°)后减小(坡度＞3°)的趋势,对深入研究山区土壤水分分布特性和水土保持具有指导意义. 相似文献
38.
利用ALOS多光谱影像及CV模型对山东沿海3种不同类型海岸-人工海岸、砂质海岸、淤泥质海岸进行海岸线提取,为比较不同特征影像对海岸线提取效果的影响,对同一类型海岸又分为近红外影像、421彩色合成影像、NDWI影像、PCA影像并分别进行海岸线提取,最后利用缓冲区分析进行精度比较。分析得出:对于人工海岸、砂质海岸2种海岸,在一个像元缓冲区内,提取精度基本可以达到80%以上,2个像元内可达到95%以上;对于淤泥质海岸,4种特征影像的提取效果均比较差,只有NDWI影像在2个缓冲区内可达到87%;总体来说,NDWI影像提取的效果最好。 相似文献
39.
数字高程模型（Digital Elevation Model, DEM）是地球表层系统科学相关研究的基础数据,DEM数据精度的定量评价对科学选择DEM数据源、量化数据误差的影响等具有重要意义。在目前全球尺度可免费获取的DEM数据中,2018年发布的TanDEM-X 90 m DEM（TanDEM-X 90）数据凭借其较好的现势性得到了广泛关注。然而,目前大区域尺度上开展的针对TanDEM-X 90数据精度的评价工作较为有限,缺乏对其整体精度及误差空间分布特征的系统认知。本文以ICESat/GLAS卫星测高数据为评价数据,并选择SRTM-3 DEM和AW3D30 DEM作为对比数据,以平均绝对误差（MAE）、均方根误差（RMSE）、偏度和峰度等为统计指标,重点研究了TanDEM-X 90在中国主要陆地区域的误差统计特征和空间分布规律,探讨了高程、坡度、地貌类型、土地覆盖等对DEM精度的影响,并进行了适用性分析。结果表明：① 在中国区域,TanDEM-X 90数据的平均绝对误差和均方根误差分别为4.31 m和7.87 m,其高程精度与SRTM-3相近,但明显低于AW3D30;② 当坡度低于4°时,TanDEM-X 90的整体精度为3种数据中最高的;③ 对于平原、丘陵、台地这3类地貌类型,TanDEM-X 90相较SRTM-3而言具有一定精度优势;④ 本研究还以流域为单元绘制了全国尺度的TanDEM-X 90误差空间分布图,为该数据在全国尺度或典型区域的应用提供重要参考。研究也表明TanDEM-X 90在反映地表高程信息方面具有更好的时效性,能更好地反映中国区域近年来受人类活动影响的地表高程变化。 相似文献
40.
Digital terrain modelling using Corona and ALOS PRISM data to investigate the distal part of Imja Glacier, Khumbu Himal, Nepal 总被引：2，自引：2，他引：0
This study used Corona KH-4A and Advanced Land Observing Satellite (ALOS) PRISM images to generate digital terrain models (DTMs) of the distal part of Imja Glacier,where a few supraglacial ponds (～0.07 km 2) expanded into the large Imja Glacier Lake (Imja Tsho,～0.91 km 2) between 1964 and 2006.DTMs and subsequently derived topographical maps with contour intervals of 1 m were created from the high-resolution images (Corona in 1964 and ALOS in 2006) in the Leica Photogrammetric Suite (LPS) platform.The DTMs and topographic maps provided excellent representation of the elevation and micro-topography of the glacier surface,such as its supra-glacial ponds/lake,surface depressions,and moraine ridges,with an error of about +/-4 m (maximum).The DTMs produced from the Corona and ALOS PRISM images are suitable for use in studies of the surface change of glaciers.The topographical maps produced from the Corona data (1964) showed that part of the dead ice in the down-glacier area was even higher than the top of the lateral moraine ridges,while the glacier surface in the up-glacier area was noticeably lower than the moraine crests.This suggests more extensive melting of glacier ice in the up-glacier area before 1964.The average lowering of the glacier surface from 1964 to 2006 was 16.9 m for the dead-ice area west of the lake and 47.4 m for the glacier surface east of the lake;between 1964 and 2002,the lake surface lowered by 82.3 m.These figures represent average lowering rates of 0.4,1.1,and 2.2 m/year for the respective areas. 相似文献