Comparing terrain and vegetation-based visibility for explaining sable flight behaviour in a Southern African savanna     

Henry Ndaimani  Amon Murwira  Shakkie Kativu 《国际地球制图》2013,28(2):130-143

In this study, we tested whether terrain-based visibility modelled from a remotely sensed ASTER Digital Elevation Model (DEM) explains sable flight initiation distance (FID) better than vegetation-based visibility measured in the field. We also tested whether the effect of hunting on sable FID varies with spatial scale. We first performed a linear regression analysis relating FID to standardized coefficients of both vegetation- and terrain-based visibility where the variable with the larger coefficient was the better predictor of FID. We latter performed an analysis of covariance (ANCOVA) comparing the slopes relating FID to both measures of visibility, first at the large scale and later at the small scale within the hunting area. Our results suggest that remotely sensed terrain-based visibility predicts the FID of sable better than vegetation-based visibility. We also found that the effect of hunting on sable FID varies with spatial scale.  相似文献   

Estimation of impervious surfaces of Beijing,China, with spectral normalized images using linear spectral mixture analysis and artificial neural network   总被引：1，自引：0，他引：1  

Xuefei Hu 《国际地球制图》2013,28(3):231-253

The objective of this article is to evaluate the effectiveness of various algorithms for estimating impervious surfaces. Linear spectral mixture analysis (LSMA) and multi-layer perceptron (MLP) network using original and spectral normalized images were applied to two ASTER images acquired on 31 August and 9 April 2004, respectively. Accuracy assessment was performed with a Quickbird image. Root-mean-square errors (RMSEs) were calculated and compared. Results indicated that LSMA with original images provided the poorest results. RMSE was 14.8% for the August image and 22.4% for the April image. Results from LSMA with normalized images improved significantly with RMSE of 12.6% for the August image and 18.9% for the April image. The MLP modelling with original images generated slightly better results with RMSE of 12.2% and 18.4% for each image. The MLP modelling of normalized images provided the best estimation, yielding a RMSE of 12.1% for the August image and 18.2% for the April image.  相似文献   

Mapping alteration minerals using sub-pixel unmixing of ASTER data in the Sarduiyeh area,SE Kerman,Iran     

《International Journal of Digital Earth》2013,6(6):487-504

This paper is an attempt to introduce the role of earth observation technology and a type of digital earth processing in mineral resources exploration and assessment. The sub-pixel distribution and quantity of alteration minerals were mapped using linear spectral unmixing (LSU) and mixture tuned matched filtering (MTMF) algorithms in the Sarduiyeh area, SE Kerman, Iran, using the visible-near infrared (VNIR) and short wave infrared (SWIR) bands of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument and the results were compared to evaluate the efficiency of methods. Three groups of alteration minerals were identified: (1) pyrophylite-alunite (2) sericite-kaolinite, and (3) chlorite-calcite-epidote. Results showed that high abundances within pixels were successfully corresponded to the alteration zones. In addition, a number of unreported altered areas were identified. Field observations and X-ray diffraction (XRD) analysis of field samples confirmed the dominant mineral phases identified remotely. Results of LSU and MTMF were generally similar with overall accuracy of 82.9 and 90.24%, respectively. It is concluded that LSU and MTMF are suitable for sub-pixel mapping of alteration minerals and when the purpose is identification of particular targets, rather than all the elements in the scene, the MTMF algorithm could be proposed.  相似文献   

Mapping salt diapirs and salt diapir-affected areas using MLP neural network model and ASTER data     

《International Journal of Digital Earth》2013,6(2):143-157

Abstract

This study employs visible-near infrared and short wave infrared datasets of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) to map salt diapirs and salt diapir-affected areas using Multi-Layer Perceptron (MLP) in the Zagros Folded Belt, Iran, and introduces the role of earth observation technology and a type of digital earth processing in lithological mapping and geo-environmental impact assessment. MLP neural network model with several learning rates between 0.01 and 0.1 was carried out on ASTER L1B data, and the results were compared using confusion matrices. The most appropriate classification image for L1B input to MLP was produced by learning rate of 0.01 with Kappa coefficient of 0.90 and overall accuracy of 92.54%. The MLP result of input data set mapped lithological units of salt diapirs and demonstrated affected areas at the southern and western parts of the Konarsiah and Jahani diapirs, respectively. Field observations and X-ray diffraction analyses of field samples confirmed the dominant mineral phases identified remotely. It is concluded that MLP is an efficient approach for mapping salt diapirs and salt-affected areas.  相似文献   

基于ASTER数据的决策树自动构建及分类研究   总被引：6，自引：3，他引：6  

李明诗  彭世揆  周林  马以秀 《国土资源遥感》2006,17(3):33-36

 在对ASTER原始9个波段数据进行各种变换处理的基础上，采用数量化指标平均可分性方法确定参与分类的最佳特征组合； 结合研究区8种主要地物类型训练数据集，分别采用最大似然法、BP神经网络法和基于See 5.0数据挖掘的决策树分类法进行分类，提取主要地物的空间分布专题信息。经过379个野外样点的验证，结果表明： 决策树算法分类性能最优，神经网络算法次之，最大似然法效果最差； 与ENVI 4.1、ERDAS 8.7提供的传统决策树建立及分类方法比较，基于数据挖掘工具See 5.0和Cart的决策树生成和分类方法具有客观、高效率、分类性能可靠和精度高等优点。  相似文献   

基于ASTER热红外数据的SiO_2含量反演在某矿田信息提取中的应用   总被引：1，自引：0，他引：1  

王俊虎  张杰林  张静波 《铀矿地质》2010,26(5):306-312

以华南某花岗岩型铀矿田为例,利用ASTER热红外数据进行了辐射定标、大气校正、温度/发射率分离及SiO2含量的定量反演,在反演图上识别出了研究区内明显的硅化断裂带、花岗岩及红层分布区,识别结果得到了实地验证。  相似文献   

Reference 3D、ASTER DEM在公路勘察设计中的应用探讨     

张霄  陈楚江  余绍淮 《中国勘察设计》2010,(5):43-46

Reference 3D是法国Spot立体卫星影像生成的DEM、ASTER DEM是高分辨率卫星成像设备—ASTER获取的立体影像生成的DEM,它们全球覆盖范围广、数据获取快、质量稳定。针对我国缺乏1:10000或1:5000基础地形资料的地区、难以获取资料的海外交通建设地区,本文探讨基于这两种DEM进行公路勘察设计。工程实践表明:Reference 3D相比ASTERDEM有着更高的精度,质量更加稳定可靠,可以满足公路勘察设计中规划、工可等阶段的需要,从而提高工作效率,缩短外业周期,降低成本。  相似文献   

利用ASTER数据融合的SRTM空值填补方法     

田明璐  常庆瑞  冯冰凛 《测绘科学》2012,37(2):86-87,102

由于雷达干涉采集误差导致SRTM数据出现高程空值,为了保证数据完整性,需要对其进行空值修补。本文总结了国内外对SRTM数据空值的填补方法,提出了一种在内插的基础上利用ASTER数据进行数据融合的空值填补方法。该方法首先对ASTER数据进行预处理,以消除两者之间的高程差异,然后利用处理后的90m间隔ASTER数据对SRTM数据进行融合,从而实现了SRTM数据的空值填补。实例验证了该方法是一种获取完整地形数据的有效途径。  相似文献   

An Urban Open Space Extraction Method： Combining Spectral and Geometric Characteristics     

ZHUGuobin DanG.Blumberg 《地球空间信息科学学报》2004,7(4):249-254

This paper introduces an advanced method based on remote sensing and Geographic Information System for urban open space extraction combining spectral and geometric characteristics. From both semantic and remote sensing perspectives, a hybrid hierarchy structure and class organization of open space are issues and mapped from one to another. Based on per-pixel and segmentation mechanism separately, two classification approaches are performed. Owing to prior of spatial aggregation and spectral contribution, the segmentation-based classification exhibits its superiority over a pixel-based classification. Finally a GIS-based post procedure is hired to eliminate some unsuitable open space components in both spatial and numerical constraints on the one hand, and separate open space some fabrics from fused remote sensing classes by defining their Shape Index on the other hand. The case study of Beer Sheva based on ASTER data proves this method is a feasible way for open space extraction.  相似文献   

基于Brovey融合与HSV锐化的ASTER影像绿地信息提取分析   总被引：1，自引：1，他引：0  

秦鹏  陈健飞 《地球信息科学学报》2009,11(3):400-404

为了突出图像的边缘、线状目标或某些亮度变化率大的部分,生成边缘图像,运用Brovey融合和HSV锐化方法,对广州市部分地区的ASTER遥感影像进行处理,然后,对两种方法分别处理后的图像,采用平行六面体法监督分类,提取城市用地信息,并对分类后的图像进行对比试验,着重对城市绿地信息的提取进行分析,探究ASTER遥感数据的两种影像处理方法对城市绿地信息的提取效果,及其空间分布为城市生态评价和景观生态建设提供必要的基础数据。通过对比试验,结果显示:Brovey方法较好地显示城市绿地的分布状况,可作为城市绿地动态监测的判别方法之一;融合后的影像能够清晰地显示研究区城市绿地的分布结构及毗邻关系;通过采用区域放大、勾画不同地类边缘轮廓、配合人工解译等工作,能够增加城市绿地与其他用地类型的差异,突显城市绿地的分布、结构、生态学特征。  相似文献