卫星遥感TM及SAR数据用于山区构造格局分析——以西藏墨脱地区为例

西藏墨脱地区山高路险，植被覆盖严重。区域地质调查中卫星遥感TM和SPOT光学图像受到植被干扰，地质构造露头不清；而微波侧视雷达图像（SAR）由于受到高山地形影响，信号遮蔽，控制点的精确选取和遥感地质解译也十分困难。研究中采用DEM（数字高程模型）模拟SAR图像的方法，利用模拟SAR图像对原始雷达图像进行控制点选取和影像正射校正，通过TM图像和SAR图像的正射影像处理以及二者的影像数据融合，并利用DEM进行三维构像，最大限度地发挥了TM图像和SAR图像的影响优及二者的影像数据融合，并利用DEM进行三维构像，最大限度地发挥了TM图像和SAR图像的影像优势，用于测区区域地质和构造解译，取得了较好效果。     

高分六号卫星遥感影像不同几何校正方法精度对比研究

为探究不同几何校正方法对高分六号影像定位精度的影响,笔者分别使用地理国情数据和GPS数据,对影像进行基于有理函数模型与多项式模型的几何校正,并运用事先布置好的检查点与校正后影像上的同名地物点进行精度分析.结果表明,利用地面控制点的几何校正中,有理函数模型的校正精度可达3.0 m(1.5个像元),多项式模型校正精度为4....     

基于遥感专题解译的白洋淀湿地底部DEM构建

基于多时相Landsat遥感影像,利用适合白洋淀湿地信息提取的综合提取方法提取湿地范围。将湿地范围视为水体淹没区,淹没区的边界线视为对应地表水位高程的等高线,并根据遥感影像、高程控制点等对淀区内受人为影响的局部区域进行校正,插值生成白洋淀湿地底部的数字高程模型(DEM)。选用遥感影像和地面高程控制点对构建的数字高程模型进行验证,遥感影像验证精度在80%以上,地面控制点验证误差在±0.5 m以内的点达到80%。这种由一系列遥感影像提取等高线生成数字高程模型的方法可以弥补白洋淀湿地内数字高程信息不足的缺陷,对于提高白洋淀湿地的水均衡计算和构建湖泊与地下水耦合模型的精度有着重要意义。     

基于RPC模型的IRS-P5影像正射校正

为了提高有理函数(rational polynomial coefficient,RPC)模型校正模型的定位精度,以IRS-P5为例,通过控制点及补偿模型的添加,比较分析了影像正射校正的精度变化.发现使用1个控制点比不使用控制点,其校正精度从55.80 m提高到5.80 m;当控制点数达到6个时,其定位精度接近于5.0 m,之后影像定位精度便不会再随控制点数的增加而提高;使用1个控制点和补偿模型,可将定位精度提高到4.0 m左右.实验表明:可通过添加少量控制点提高RPC模型的正射校正精度,在缺少控制点的情况下,使用补偿模型亦能使RPC模型达到相当的影像校正精度.      

利用ASTER卫星立体像对提取喀斯特数字地形模型——以广西大化高峰丛深洼地喀斯特地貌为例

ASTER卫星立体像对已经被成功地用于提取全球数字地形模型（DEM）,其有效性已经在不同类型的非喀斯特地貌区域得到验证。和一般地貌相比,喀斯特地形,特别是中国南方喀斯特,具有自己独特的形态特征。能否从ASTER影像中精确地提取喀斯特地貌DEM目前尚未见到有任何报道。本文利用ASTER影像成功地提取了广西大化地区高峰丛深洼地的喀斯特地貌DEM,并且将提取结果与同一地区1∶5万地形图控制点的高程和4个剖面的高程变化进行了对比。研究区内绝大部分区域是喀斯特地貌,但在其西北部有一舌状砂岩地貌分布,从而提供了一个很好的喀斯特和非喀斯特地貌DEM精度对比的机会。本文的研究结果表明,从ASTER影像提取出来的砂岩地貌的DEM均方根误差要小于喀斯特地区,表明从ASTER影像中能更有效地提取非喀斯特地貌的DEM。相比之下,提取得到的喀斯特DEM精确度则稍差。究其原因主要是因为研究区内独特的高峰丛深洼地地形形态。由于峰丛地形的阴影在构成立体像对的两幅影像（nadir-looking和aft-loo-king）上的大小和形态差异很大,导致了DEM生产过程中两幅影像不能精确配准,从而产生比较大的误差。相比之下,砂岩地区地貌相对比较平坦,地形阴影大小和形态在两幅影像上差别不大,故而能得到精度比较高的数字地形模型。本文研究结果同时还表明适当增加地面控制点能在一定程度上改善提取出来的喀斯特地貌DEM的精度。尽管提取的数字地形模型精度稍低,其均方根误差仍然远远小于该地区峰丛和洼地个体体量。因此本研究认为从ASTER立体像对提取的数字地形模型可广泛用于喀斯特地貌形态特征研究。     

基于MAPGIS坐标系转换的ETM影像配准方法研究

美国马里兰大学GLCF的Landsat7 ETM影像(L1G级)采用WGS-84坐标系,而我国中小比例尺地形图一般采用西安80或北京54坐标系,要将马里兰大学GLCF的ETM影像与地形图配准,一般采集地面控制点(GCP)进行多项式几何纠正。但GCP的选取过程一直为一项繁杂的工作,常用的方法选取效率不高,精度不易控制。本文通过Map GIS坐标系转换的方法来实现ETM影像的快速配准,避免了繁杂的GCP选取过程,同时又保证了影像的配准精度,不失为一个较好的影像配准方法。     

正射遥感影像地图制作技术在岷江上游滑坡研究中的应用

正射遥感影像地图是对遥感数学字图像进行几何校正和投影差改正,并与数字化的简化地形图复合的一种新图,或是直接用遥感图像采用特定方法生成的具有地形地素的一种新的图种。该文介绍了陆地卫星ＴＭ正射影像地图的制作;利用卫星正射遥感影像地图,分析、解译出岷江上游地区８７个滑坡和崩塌体。采纳数据融合技术,对该区正射遥感影像进行重建,突出地形细节,提高了滑坡和崩塌体的解译精度。３Ｓ技术结合,对岷江上游地区进行了三     

基于GIS技术的三维矿山遥感可视化方法研究

以RS和GIS作为数据获取与分析处理的技术手段,对spot-5数据进行了图像的合成、几何纠正、融合和正射校正处理后,以ArcGIS作为数据平台,利用数字高程模型（DEM）,生成不规则三角网,对地形进行三维模拟,叠加遥感影像,制作了矿山遥感的三维立体遥感影像图。实践证明,三维遥感可视化的应用,对揭示矿山的空间分布规律、野外路线选取、野外验证工作困难的区域以及指导矿山生产实践都具有非常重要的现实意义,同时可以叠加矿权等矢量数据信息,实现多源数据的空间分析,为矿山遥感多目标监测工作提供直观、准确的数据,节省时间、减少成本。     

基于InSAR和ICESat的南极冰盖地区DEM提取和精度分析

结合InSAR和ICESat测高数据,以东南极PANDA断面4个实验区为例,进行DEM生成研究.在干涉相位转换成高程前,引入ICESat测高数据作为控制点优化干涉对基线,消除基线线性误差趋势的影响.利用控制点之外的ICESat测高数据分析4个实验区的DEM精度及其差异,并探讨了引起DEM误差的原因.冰流和地貌特征是影响InSAR生成冰盖DEM精度的重要因素.针对冰流的影响,从理论上进行了分析并结合冰流速数据进行了分析验证.最后利用克里金插值法改正InSAR DEM残余误差,并利用GPS实测控制点对改正效果进行验证.结果表明:对于高纬区流速较小且分布一致的区域,改正效果很好,DEM精度可达3 m;而对于冰流速较大且复杂的地区,需采用多基线等算法进一步消弱冰流引入的误差.     

论二维几何纠正与三维数字微分纠正异同

用多项式进行遥感影像的二维纠正回避构像的空间几何过程,简单易行,适用于各种传感器影像,普遍用于2幅图像之间的配准。二维纠正未考虑地形引起的变形影响,是一种近似解法。结合DEM的共线方程三维数字微分纠正,是对构像空间几何形态直接描述,对传感器成像时的位置和姿态进行模拟。当外方位元素解算精度较高时,可获得理想的正射影像图。     

基于KH-9数据对青藏高原山地冰川DEM提取及精度评价——以普若岗日冰川和雅弄冰川为例

针对青藏高原山地冰川区早期DEM数据缺乏、精度低、覆盖范围小等问题,以普若岗日冰川和雅弄冰川为例,利用解密的早期高分辨率间谍卫星KH-9立体像对,建立了基于KH-9数据的山地冰川DEM提取技术流程,并以ICESat GLAS高程数据为基准对提取的DEM进行了精度评价和精度影响分析。结果表明：无论是在普若岗日冰川区还是雅弄冰川区,所获取的DEM精度均完全满足估算山地冰川长时间尺度物质平衡的精度要求。KH-9数据具有空间分辨率高,地面覆盖范围广,成像时间较早（1971-1980年）等特点,可为山地冰川物质平衡研究提供很好的基础数据源。     

Coupling of DEM and remote-sensing-based approaches for semi-automated detection of regional geostructural features in Zagros mountain, Iran

In recent years, remote-sensing data have increasingly been used for the interpretation of objects and mapping in various applications of engineering geology. Digital elevation model (DEM) is very useful for detection, delineation, and interpretation of geological and structural features. The use of image elements for interpretation is a common method to extract structural features. In this paper, linear features were extracted from the Landsat ETM satellite image and then DEM was used to enhance those objects using digital-image-processing filtering techniques. The extraction procedures of the linear objects are performed in a semi-automated way. Photographic elements and geotechnical elements are used as main keys to extract the information from the satellite image data. This paper emphasizes on the application of DEM and usage of various filtering techniques with different convolution kernel size applied on the DEM. Additionally, this paper discusses about the usefulness of DEM and satellite digital data for extraction of structural features in SW of Zagros mountain, Iran.     

Accuracy assessment of InSAR derived input maps for landslide susceptibility analysis: a case study from the Swiss Alps

In recent years SAR interferometry has become a widely used technique for measuring altitude and displacement of the surface of the earth. Both these capabilities are highly relevant for landslide susceptibility studies. Although there are many problems that make the use of SAR interferometry less suitable for landslide inventory mapping, it’s use in landslide monitoring and in the generation of input maps for landslide susceptibility assessment looks very promising. The present work attempts to evaluate the usefulness and limitations of this technique based on a case study in the Swiss Alps. Input maps were generated from ERS repeat pass data using SAR interferometry. A land cover map has been generated by image classification of multi-temporal SAR intensity images. An InSAR DEM was generated and a number of maps were derived from it, such as slope-, aspect, altitude- and slope form classes. These maps were used to generate landslide and rockfall susceptibility maps, which give fairly well acceptable results. However, a comparison of the InSAR DEM with the conventional Swisstopo DEM, indicated significant errors in the absolute height and slope angles derived from InSAR, especially along the ridges and in the valleys. These errors are caused by low coherence mostly due to layover and shadow effects. Visual comparison of stereo images created from hillshading maps and corresponding DEMs demonstrate that a considerable amount of topographic details have been lost in the InSAR-derived DEM. It is concluded that InSAR derived input maps are not ideal for landslide susceptibility assessment, but could be used if more accurate data is lacking.     

ARC/INFO在流域水文分析中的应用

以吉林东部某山区小流域水文分析为例,将地理信息系统(GIS)与流域研究相结合,运用ARC/INFO的图像处理功能建立流域数字高程模型(DEM),利用其表面分析功能进行坡度、坡向、流线和流域识别等分析,实现GIS在流域水文分析中的应用。结果表明:运用ARC/INFO分析得到的流域坡度、坡向、流线及流域边界划分合理,输出结果直观美化,并在此基础上预测降水的汇流方向,效果较好。实现了对地形的三维化,提供了一种山区流域水文分析方法。     

基于三方向搜索的DEM中洼地处理方法

数字高程模型(DEM)是流域参数提取的基础,然而DEM中普遍存在的洼地和平地影响了流域水系的自动提取,因此洼地去除方法成为研究的热点。针对现有洼地去处方法存在的问题,提出了一种基于"三方向搜索"的洼地处理方法。该方法通过对洼地及其周围网格高程值增减来达到去除洼地的目的,避免了传统填洼方法大规模的对DEM进行增高处理。实验结果表明,该算法简单易行,能有效的去除洼地,消除DEM提取的河网中的伪河道及"平行线"现象;且对DEM中高程值的改动较小,从而较大限度的保留了原始地形信息。     

基于SBAS-InSAR技术的深切割高山峡谷区滑坡灾害早期识别

近年来,高山峡谷区滑坡灾害频频发生,给人民生命和财产安全带来严重威胁。针对多数学者利用SAR单轨道数据对高山峡谷区滑坡进行早期识别,存在SAR成像几何畸变造成部分滑坡不能识别、识别结果不全面等问题。为全面准确的对高山峡谷区滑坡隐患进行早期识别,文章采用SBAS-InSAR技术,以东川小江沿线两侧深切割高山峡谷区为研究区,通过升降轨SAR数据结合互补的方式进行滑坡灾害隐患识别,引入高分辨率光学影像等作为辅助识别,最终共识别出18处滑坡灾害体,其中5处为高风险潜在滑坡,并对三类典型潜在滑坡进行分析。分析结果表明:利用升降轨SAR数据结合互补的方式,能有效避免SAR单轨道数据在高山峡谷地区产生的几何畸变问题,同时,该方法能更为准确全面地对高山峡谷区滑坡隐患进行早期识别,为防灾减灾事业及政府部门决策提供一种有效的手段。     

Ground subsidence in Semarang-Indonesia investigated by ALOS–PALSAR satellite SAR interferometry

The focus of this study is investigation of land subsidence in Semarang city Indonesia with the use of Interferometry Synthetic Aperture Radar (InSAR) of ALOS–PALSAR satellite. We processed 22 ascending SAR images during January 2007 to January 2009 plus two descending SAR images acquired on 6 June 2006 and 17 June 2007. The time series analysis of interferometry was performed by using 12 pairs of interferogram relative to 21 January 2007 and 8 pairs of interferogram relative 24 January 2008. The topographic phase contribution was removed using the 3-arcsec (90 m) Shuttle Radar Topography Mission (SRTM), Digital Elevation Model (DEM). We performed precision baseline estimation to vanish the fringes from baseline effect between master and slave data. In order to investigate the contribution of horizontal movement in our analysis, we constructed two interferograms of ascending orbit and descending orbit. The time series results exhibited that the area is subsiding continuously without a significant seasonal effect during January 2007 to January 2009. The land subsidence observed from InSAR data is approximately up to 8 cm/year. Three cross sections on image displacement show the extreme land subsidence occurred especially along the coastal area and lowland area where this area is considered as industrial with high-density settlements, consuming a lot of groundwater, and land is changed from agriculture and cultivation purposes to industrial estates and house. Our result also shows a consistency with historical pattern of subsidence measured by leveling data. The results highlight the potential use of InSAR measurements to provide better constraints for land subsidence in Semarang city Indonesia.     

基于高精度DEM的地形监测方法研究

基于非接触的遥感手段的DEM采集精度越来越高,如何运用好高精度DEM成为关键.介绍了包括LiDAR、合成孔径雷达、摄影测量技术等遥感手段采集高精度DEM的方式及处理流程.DEM在地质、地貌、土壤、国防建设方面均有着广泛的应用,就基于高精度DEM的地形监测方法展开试验和讨论,对比不同分辨率（1,10,30 m） DEM影像展示效果,得出高精度DEM在展示与分析方面的优点,通过计算山体阴影、坡度、地形曲率,研究了基于单期高精度DEM的不同地形监测方法.     

SAR image analysis techniques for flood area mapping - literature survey

Flood area mapping is an integral part of disaster management operation which gets value when the details about inundated region has been made available in real time mode as well as when the much required temporal information is shared to the disaster mitigation authorities at right time. The challenges of such real time flood area mapping operations can be met by spaceborn Synthetic Aperture Radar (SAR) technology which is capable of capturing the critical information of large and hard-to-reach territories during all weather and all time situations. Mapping the flood related information of SAR images require much attention as the pixels associated with the inundated regions exhibit similar reflectance with major part of the pixels associated with high altitude region, shadow, runway and broad road networks. Such challenges have been addressed by worldwide researchers with the help of image processing functions. Many such SAR image based flood area mapping models take the advantages of various image classification approaches as well as in integrating multiple image processing functions mainly to differentiate the inundated pixels from other pixels which exhibits similar reflectance by which the mapping accuracy is enhanced. This paper is dedicated, in understanding and documenting various such significant SAR image based flood area mapping models by highlighting its strengths. Significant SAR image bases flood area mapping models from 1990’s to 2015 has been discussed. The respective references can be used by young researchers who are interested and willing to work in SAR image based flood area mapping techniques.