Monitoring mangrove forests: Are we taking full advantage of technology?     

《International Journal of Applied Earth Observation and Geoinformation》2017

Mangrove forests grow in the estuaries of 124 tropical countries around the world. Because in-situ monitoring of mangroves is difficult and time-consuming, remote sensing technologies are commonly used to monitor these ecosystems. Landsat satellites have provided regular and systematic images of mangrove ecosystems for over 30 years, yet researchers often cite budget and infrastructure constraints to justify the underuse this resource. Since 2001, over 50 studies have used Landsat or ASTER imagery for mangrove monitoring, and most focus on the spatial extent of mangroves, rarely using more than five images. Even after the Landsat archive was made free for public use, few studies used more than five images, despite the clear advantages of using more images (e.g. lower signal-to-noise ratios). The main argument of this paper is that, with freely available imagery and high performance computing facilities around the world, it is up to researchers to acquire the necessary programming skills to use these resources. Programming skills allow researchers to automate repetitive and time-consuming tasks, such as image acquisition and processing, consequently reducing up to 60% of the time dedicated to these activities. These skills also help scientists to review and re-use algorithms, hence making mangrove research more agile. This paper contributes to the debate on why scientists need to learn to program, not only to challenge prevailing approaches to mangrove research, but also to expand the temporal and spatial extents that are commonly used for mangrove research.  相似文献   

三维卫星遥感图像生成技术及其在第四纪构造地貌研究中的应用   总被引：7，自引：0，他引：7       下载免费PDF全文

付碧宏  二宫芳树  董彦芳  时丕龙  张之武 《第四纪研究》2008,28(2):189-196

近年来一系列中高分辨率立体成像卫星传感器相继发射成功,如法国的SPOT卫星、日本的ASTER和ALOS卫星,它们除了具有获取多光谱遥感数据的能力外,还具有立体成像的功能。随着计算机图像处理技术和卫星遥感立体成像技术的不断发展,地质体及其地形地貌的三维图像生成及其可视化技术得到了迅速发展。本研究介绍了利用ER-M apper图像处理软件提供的三维图像生成及可视化技术,将ASTER卫星遥感数据生成的数字高程模型与多光谱图像信息有机融合,生成地质体三维可视化图像,再现地质体的三维空间特征,从而从整体上直观、综合地对活动地质构造及其构造地貌特征进行可视化分析研究。本研究重点介绍了ASTER三维可视化立体遥感图像在晚第四纪活动构造和第四纪火山地貌研究中的应用,并展示了在阿尔泰山富蕴断裂带、北天山独山子背斜带、东昆仑断裂带以及长白山天池火山的研究实例。  相似文献   

ASTER数据在深圳东部滨海地区土地利用调查中的应用     

田波  周云轩  蒋云安  侯长谋 《吉林大学学报(地球科学版)》2008,38(1):121-128

以深圳市东部滨海地区为试验区,对2004年11月21日ASTER遥感数据进行辐射和几何精校正处理,实地建立分类样地;根据多边形样地矢量数据计算分析12类地物在ASTER各波段光谱反射图和分类叠合图,同时进行植被指数和短波红外5个波段主成分分析;结合GIS并利用ASTER光谱波段、第一主成分、植被指数、立体像对生成的地形因子建立土地利用分类决策树表;再根据决策树表对ASTER影像进行土地利用分类。经验证,分类结果总体精度达到85.1%。应用效果表明,利用ASTER数据进行土地现状资源调查具有很好的性价比,能够满足土地利用现状调查的准确度和精度。  相似文献   

Vertical accuracy assessment of freely available digital elevation models over low-lying coastal plains     

Xiaoping Du  Huadong Guo  Xiangtao Fan  Junjie Zhu  Zhenzhen Yan  Qin Zhan 《International Journal of Digital Earth》2016,9(3):252-271

The frequency of coastal flood damages is expected to increase significantly during the twenty-first century as sea level rises in the coastal floodplain. Coastal digital elevation model (DEM) data describing coastal topography are essential for assessing future flood-related damages and understanding the impacts of sea-level rise. The Shuttle Radar Topography Mission (SRTM) and Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM) are currently the most accurate and freely available DEM data. However, an accuracy assessment specifically targeted at DEMs over low elevation coastal plains is lacking. The present study focuses on these areas to assess the vertical accuracy of SRTM and ASTER GDEM using Ice, Cloud, and land Elevation Satellite, Geoscience Laser Altimeter System (ICESat/GLAS) and Real Time Kinematic (RTK) Global Positioning System (GPS) field survey data. The findings show that DEM accuracy is much better than the mission specifications over coastal plains. In addition, optical remote sensing image analysis further reveals the relationship between DEM vertical accuracy and land cover in these areas. This study provides a systematic approach to assess the accuracy of DEMs in coastal zones, and the results highlight the limitations and potential of these DEMs in coastal applications.  相似文献   

Using geoinformatics and geomorphometrics to quantify the geodiversity of Crete,Greece     

《International Journal of Applied Earth Observation and Geoinformation》2016

The geodiversity of Crete is quantified in this study, based on the classification of geomorphometric, geological and climatic factors. A number of geomorphometric variables, extracted from the ASTER Global Digital Elevation Model (ASTER G-DEM) in conjunction with geological and climatic information, are evaluated through various algorithms incorporated into Geographical Information System (GIS) software’s. The derived geoinformatic data sets are then analyzed to produce the geodiversity of Crete. The geodiversity map is used to quantify the geodiversity, by calculating landscape diversity and other spatial pattern indices. Those indices are evaluating the richness, evenness, fragmentation and shape of the landscape patch types. The outcome of this study has highlighted that western Crete is characterized by complex geodiversity with more irregular, elongated and fragmented landscape patterns relative to the eastern part of the island. The geodiversity indices provide insights into the processes shaping landscapes, particularly the “battle” between neotectonic landscape deformation and erosion/deposition. The methodology presented can be useful for decision makers when evaluating a regions geological heritage, planning the management of natural resources, or designating areas for conservation.  相似文献   

基于ASTER光谱特征的科技廊带岩性填图:以新疆塔什库尔干地区为例   总被引：3，自引：0，他引：3  

张瑞丝  曹汇  曾敏  张德贤  李广旭 《岩石学报》2016,32(12):3835-3846

科技廊带填图是以解决关键地质问题为目的填图方式,但部分地区海拔高差大,交通不便,给填图工作造成巨大困难。遥感岩性解译可为填图工作提供重要参考。然而,当前主流的遥感岩性解译方法仍是基于地貌纹理等间接解译标志开展的。相对而言,矿物岩石光谱特征作为最为直接和准确的遥感岩性解译标志却少有实例报道。本文基于ASTER遥感影像和岩石光谱特征分析,对部分地区海拔高差较大的新疆塔什库尔干地区进行岩性解译工作,以检验其适用性。在野外工作对研究区岩性类型进行识别和鉴定的基础上,ASTER光谱分析成果影像可较准确显示区内主要岩性类型的地表出露。其中,ASTER热红外波段比可反映区内中高级变质岩、花岗岩类及碳酸盐岩的整体分布特征;在此基础上,ASTER可见光-近红外及短波红外波段比可准确鉴定与Fe~(3+)、Fe~(2+)-硅酸盐、Al-OH、Mg-OH等成分相关的矿物组成(如绿泥石、白云母及石榴子石等),从而对地表岩性出露进行更为细致的识别和分类。研究结果表明基于ASTER光谱特征的岩性填图方法在新疆、西藏等地区有天然的实用性,既可克服区内海拔高、交通不便等困难,又可准确指示地表关键岩性类型的出露情况,可作为科技廊带填图及地质研究工作的重要手段。  相似文献   

基于ASTER数据反演我国南方山地陆表温度   总被引：13，自引：1，他引：13  

王凤敏  田庆久  虢建宏 《国土资源遥感》2005,16(1):30-33

 以贵州省黎平县山地植被覆盖区为例，基于ASTER遥感数据进行15 m分辨率的归一化植被指数制图和地表发射率制图，在利用 MODTRAN 4大气辐射传输模型进行大气订正的基础上，基于普朗克辐射方程的推导反演陆表温度，取得了较为理想的结果。  相似文献   

High-accuracy topographical information extraction based on fusion of ASTER stereo-data and ICESat/GLAS data in Antarctica   总被引：1，自引：0，他引：1  

E. DongChen  Qiang Shen  Ying Xu  Gang Chen 《中国科学D辑(英文版)》2009,52(5):714-722

In order to better support Antarctic inland ice sheet expedition from Zhongshan Station to Dome A, the topographic data are necessary. At present, although the entire Antarctic DEM provided by RAMP (Radarsat Antarctic Mapping Project) was estimated at the highest horizontal (spatial) resolution of about 200 m, the real horizontal resolution of the DEM varies from place to place depending on the density and scale of the original source data. For ice shelves and the inland ice sheet, the horizontal resolution is about 5 km; the vertical accuracy is estimated to be ±50 m in interior East Antarctic ice sheet and away from the mountain ranges. Therefore, more accurate topographic data are unavailable in Antarctica. In order to meet the requirements of high-accuracy topographic information for further researches, this paper mainly addresses a fusion study of ASTER stereo pairs and ICESat/GLAS altimetry data for extraction of high-accuracy DEM in East Antarctica, based on the high horizontal resolution (15 m) of ASTER and vertical accuracy (13.8 cm) of ICESat/GLAS. First, some altimetry data were selected as vertical control points to reduce errors of image correlation matching during the extraction of ASTER-based DEM. Second, ice sheet altimetry data derived from ICESat were used to generate DEM ranging from 75° to 81°S because existing ASTER data do not cover this area and high density of the coverage of ICESat altimetry data. Finally, the DEM in coverage of the expedition route was produced. The analysis of result reveals that the DEM accuracy is improved significantly. The absolute vertical accuracy of DEM is higher than 15 m in some cases and higher than 30 m for all the areas along the expedition route except from the 009-001 scene; the interior accuracy is higher than 15 m and higher than 7 m in some cases. It can meet the requirements of topographic map at 1:50000 scale, which is an economic and advantageous method to produce the topographic products. Supported by National Natural Science Foundation (Grant No. 40606002), Surveying and Mapping in Chinese Antarctic Expedition Area (Grant No. 1469990711109-1), National Key Technology R & D Program (Grant No. 2006BAD18B01), and GLA12 dataset of ICESat/GLAS in National Snow and Ice Data Center (NSIDC)  相似文献   

基于ENVI软件的ASTER卫星正射影像图研制——以阜康地区为例     

陈冬花  李虎  杨昕垚  孙伟 《地球信息科学学报》2006,8(3):37-40

ASTER卫星数据是近年来使用较多的一种新型遥感数据源。本文以阜康地区为研究区域,利用遥感图像处理软件ENVI对ASTER卫星数据进行了影像镶嵌图研制。研究表明ASTER卫星镶嵌数据体现了诸多优势。同时,本文阐述了在影像镶嵌处理中发现的问题及今后的发展趋势。  相似文献   

基于ASTER数据遥感影像的决策树分类   总被引：6，自引：0，他引：6  

程彬  姜琦刚  周云轩  湛邵斌 《吉林大学学报(地球科学版)》2007,37(1):179-184

以黑龙江省北安市为研究区域,尝试利用ASTER视反射率值进行便利、准确的土地利用分类研究。对ASTER数据进行波段相关分析,确定最佳组合波段;然后重点分析转换为视反射率值的影像特征和光谱特征,从中提取各种典型地物的光谱曲线; 并依据提取的光谱曲线建立基于地物反射率值大小关系或阈值的决策树模型,对研究区不同地物类型进行分类,并对结果进行精度评价。应用效果表明,该方法简单有效,但对于混合光谱容易错分。  相似文献