基于资源三号和ETM~+影像的断裂构造解译

以资源三号影像、ETM+影像为数据源,在分析断裂构造遥感影像特征基础上,研究断裂构造解译中的遥感图像处理方法,运用灰度拉伸、图像融合、定向滤波等方法进行增强处理,依据解译标志进行人机交互解译。对鄂尔多斯盆地的断裂构造进行了综合分析,证明高空间分辨率的资源三号影像与多光谱分辨率的ETM+影像相结合的遥感技术在断裂构造解译方面具有可行性。     

矢量C-V模型的高光谱遥感影像分割

高光谱遥感影像除了包含普通2维影像所具有的空间信息还包含了1维光谱信息,传统的针对2维影像的分割方法不能很好地应用于高光谱遥感影像。为此,本文提出一种能够同时处理多波段影像的高光谱遥感影像矢量C-V模型分割方法。首先选出高光谱遥感影像中目标与背景对比度较大的波段,并通过计算波段相关系数,去除其中的冗余信息形成新的波段组合,进而根据所确定的波段组合构建高光谱遥感影像矢量矩阵;在此基础上,构造基于该矢量矩阵的矢量C-V分割模型。模型中通过引入基于梯度的边缘引导函数,在保留传统C-V模型基于区域信息进行影像分割的基础上,利用影像的边缘细节信息,增强了模型在异质区域和复杂背景情况下对目标边缘的捕捉能力,提高了对高光谱遥感影像的分割精度和速度。最后利用HYPERION数据进行仿真实验,并将实验结果和传统C-V模型和相关方法进行了对比,结果表明,本文方法能够在短时间内有效地分割高光谱遥感影像,与传统方法相比,具有分割精度更高运算速度更快的特点。     

GF-3全极化影像在地表浅覆盖区进行地质构造解译的新方法

地质构造信息对地质矿产调查具有重要意义,野外实测和光学遥感等常规手段在一些地表浅覆盖区获取的地质构造信息十分有限,而合成孔径雷达(SAR)对地表具有一定的穿透性,在探测地表浅层覆盖区域的地质构造特征中具有独特优势。利用高分三号(GF-3)全极化影像,在典型的地表浅层覆盖区域,开展了断裂构造等信息的解译探索,提出了一种地表浅覆盖区域地质构造解译的新方法。首先对西藏改则、林芝、贵阳、北京千家店等4个研究区内的断裂构造和环带构造进行分析;接着,提出了GF-3全极化影像用于浅覆盖区地质解译的处理流程,通过引入DEM数据对GF-3影像进行地形校正,充分利用微地形微地貌特征,并采用不同极化方式的RGB合成,增强了影像的判读性,并进行地质构造解译;最后,将解译结果与1∶5万实测数据进行对比,断层的位置和方向与实测结果基本一致,同时获取了大量野外实测未能探明的浅覆盖层以下的断层信息,进一步丰富了研究区的地质构造信息。结果表明,GF-3全极化影像可用于浅覆盖区的地质构造解译,并且具有野外实测和光学遥感等常规手段所不能替代的独特优势。     

基于ZY-102C星数据的遥感地质解译——以塔吉克斯坦帕米尔地区为例

为了对境外地质矿产勘查开发提供遥感信息支持,在综合前人研究成果及野外验证基础上,对塔吉克斯坦帕米尔地区的地质和构造特征进行深入分析和研究;根据不同地质体的特征影像,对照"资源一号"(ZY-1)02C星遥感图像中所显示的地貌景观、色调及纹形等,建立了塔吉克斯坦南部地区主要沉积岩、变质岩和侵入岩以及断裂构造、褶皱构造和环形构造等的遥感解译标志;通过对ZY-1 02C星的全色/多光谱相机(P/MS)和全色高分辨率相机(HR)数据的遥感地质解译效果对比,认为P/MS数据中地质体的色调差异更为明显,易于建立区域构造格架、开展岩石大类解译;而HR数据所反映地质体的微地貌、纹理及细节更为清晰,易于进一步识别各类岩性及小型构造,尤其对碎屑岩的粒度、层状构造类型、第四系、矿业活动以及特殊成分的岩石等具有较好的反映。     

PALSAR数据在植被覆盖区构造信息提取中的应用

为解决光学遥感在植被覆盖区地质构造信息难以识别提取的问题,利用具有一定穿透能力的L波段PALSAR双极化雷达数据对福建寿宁地区开展了研究。对双极化雷达图像进行了假彩色合成、滤波增强,针对HH极化通道将灰度图像变换成HSV彩色图像,突显了地质信息,并与该区ASTER多光谱影像进行了对比,分析了雷达影像优劣。结果表明PALSAR雷达构造解译结果与研究区的区域主要断裂方向基本一致,PALSAR雷达数据可以作为高效、准确的方法 ,在植被覆盖区开展遥感地质工作。     

四种遥感浅海水深反演算法的比较

详细介绍了单波段线性回归模型、两波段比值线性回归模型、多波段组合线性回归模型、BP神经网络模型等4种光学遥感水深反演算法,然后利用同一地区、同一时期的Worldview-2多光谱遥感影像和实测水深数据,对4种水深反演模型的准确性进行了实验比较。研究表明:多波段组合线性回归模型、BP神经网络模型的水深反演的性能较好,利用多光谱遥感图像数据反演得到的水深值误差较小;而单波段线性回归模型、两波段比值线性回归模型的效果较差。     

麻城—团风断裂带分段活动特征遥感调查

遥感图像可以从宏观上反映活动断裂的空间展布规律和构造特征。在区域地质特征分析基础上,采用数据预处理、信息增强和数据融合等图像处理方法,提高了遥感图像的清晰度和可解译程度;根据遥感图像光谱特征和几何特征建立断裂构造带解译标志,进行断裂构造带及其活动性解译;结合野外调查,对麻城—团风断裂带进行了宏观分析和分段性活动的初步研究。研究结果表明:麻城—团风断裂带可按其控制力强弱分为北、中、南3段,北段图像线性特征明显,断裂解译标志显著;中段断裂控制力减弱,图像线性特征较模糊;南段为隐伏断裂。遥感技术在麻城—团风断裂带活动性调查中发挥了重要作用,特别是高分辨率遥感图像和遥感图像处理技术的应用不仅可以加快调查进度,还能为实地调查提供指导信息,从而显著提高调查效率与精度。     

基于多源遥感数据西藏山南地区活动断层解译

利用多源遥感数据从多尺度重新对西藏山南地区活动断层进行遥感解译,并综合前人研究成果对其位置及活动性进行判定。首先,采用具有全天候和穿透性的Sentinel-1雷达图像和光谱信息丰富的Landsat ETM+影像作为主要数据源,并结合高空间分辨率的高分二号遥感影像,提取并分析不同尺度的地质构造信息;其次,将DEM数据与ETM+遥感影像进行融合,获取三维可视化遥感影像,方便从不同角度、不同层次进行活动断层的构造地貌分析;最后,综合雷达遥感与光学遥感各自的成像优势,利用图像预处理、图像增强处理与多源遥感图像融合等处理来降低活动断层遥感解译的多解性与可疑性,明晰了西藏山南研究区的活动断层遥感影像特征。根据活动断层遥感解译标志,在研究区共解译出主要活动断裂带4条,分别为:雅鲁藏布江断裂带、札达—拉孜—邛多江断裂带、桑日—错那断裂带和达吉岭—昂仁—仁布断裂带。研究区的活动断层解译结果表明,综合应用多源遥感数据可以大大提高活动断层解译的准确率与可信度,并为研究区后续研究提供借鉴。     

基于小波变换的大面阵CCD相机影像亮度不一致性消除算法

针对大面阵CCD影像亮度不均匀现象，提出一种基于小波变换的影像亮度不一致性消除算法。在分析像面光照模型的基础上，构造出光照模型的仿真影像，通过分析仿真影像的小波变换系数，发现影像亮度不一致信息集中反映在小波的近似系数之中。利用这一特性，先将数字相机原始影像进行多尺度小波分解，并对近似系数取对数，然后施加一个衰减算子，对近似系数的对数进行非均匀改正，将改正后的系数取指数，再对近似系数进行线性拉伸，同时根据人类视觉系统对不同方向细节敏感度的不同，对不同方向的细节系数进行不同幅度的线性拉伸，以突出图像细节，最后通过影像重建，获得均匀亮度的航空影像。实验结果显示，该算法具有很好的匀光效果，同时能够较好地保持影像细节特征。     

一种基于NSCT和方向信息测度的GF1影像融合方法

结合NSCT变换和方向信息测度在影像融合表达中的优势,针对GF1影像的特征,提出了多光谱波段与全色波段影像融合过程中采用基于NSCT变换域的方向信息测度融合方法。以GF1影像为源数据,通过NSCT多尺度多方向分解后,对低频系数使用基于区域灰度方差的融合方法,对高频系数采用了改进的方向信息测度加权融合方法,经NSCT逆变换重构影像实现融合。试验结果表明,基于NSCT变换和改进方向信息测度结合的融合方法能更好地保持多光谱影像的光谱信息和全色影像的空间信息,具有更多的细节特征及更清晰的边缘,因此提高了遥感影像的解译精度和解译效率,可为目标信息的提取应用提供支撑。     

Evaluation and integration of ERS-1-SAR and optical sensor data (TM and IRS) for geological investigations

The C-band imaging radar of ERS-1, due to its high sensitivity to terrain surface features, holds tremendous potential in topographic terrain mapping for various applications. This is being examined for geological applications, mainly structural and lithological mapping in a mineral belt of Bihar and Orissa, India. The high image contrast that facilitates structural interpretation and highlights topography on the SAR images, reflects the high sensitivity of the ERS-1-SAR to change in terrain slope in the study area. Extensive lineaments, fold structure and major lithological contacts are easily mappable from the SAR imagery. Many of the lineaments, lithological contacts and fold pattern are mapped equally from optical data (Landsat-TM and IRS-1B FCC). The close association of fold pattern and mineral deposits in the region has necessitated the study of those structures carefully from various remote sensing data products. Synergism between SAR and TM provided useful results regarding structure and lithology of the region. The advantage of SAR in highlighting topography and detecting lineaments are affected to a great extent by the speckle noise and low pixel resolution. The present study shows that future geologic interpretation demands high spatial resolution and efficient data processing technique which reduces the speckle noise more significantly.     

Assessing image processing techniques for geological mapping: a case study in Eljufra,Libya

Various image processing techniques were experimented with in this study to evaluate their efficiency for geological mapping in the Eljufra area of northwest Libya. Remote sensing data including multi-spectral optical Landsat Enhanced Thematic Mapper (ETM+), Synthetic Aperture Radar (ERS-2 SAR) and Digital Elevation Models (DEMs) extracted from the Shuttle Radar Topography Mission (SRTM) data were used to trace different lithological units as well as extracting geological lineaments in the study area. The study area is located in an arid environment mostly devoid of any vegetation. Most lithological and structural units are distinguishable based on their topographic form and spectral properties. Fusion of ETM+ and ERS-2 images was experimented with to further identify lithological units. Shaded relief techniques were implemented to enhance terrain perspective views and to extract geological lineaments. The results discriminated different rock units and modified formation boundaries and revealed new geological lineaments. Nine rock units were identified and plotted in the new geological map defined by the new boundaries. The dominant lineaments tend to run in the NNW-SSE and NNE-SSW directions. Analysis and interpretation of the lineaments provided information about the tectonic evolution of the study area.     

Usage of ERS SAR data over the Singhbhum Shear Zone,India for structural mapping and tectonic studies

The extraction of lineaments and anomalous patterns in the Singhbhum Shear Zone, Jharkhand, India, has multifaceted applications for mineral exploration as well as for geological interpretation of neotectonic movements. ERS-1 SAR data are very useful for such applications because of their structural information content. A comparative study has been attempted with ERS, Landsat and IRS images for the interpretation of various geological structures over the Singhbhum Shear Zone. The Rose diagram generated from this study has shown major trends that matched well with the geological map of the area and the associated tectonic boundary as well as with the results obtained from ground based studies.     

Delineation and assessment of Central Indian Suture through lineament extraction approach using Remote Sensing and Geographic Information System

Lineament extraction approach allowed mapping of larger number of lineaments in a classical manner in tectonic and structural studies. In the present study, various techniques were adopted to extract lineaments using Landsat ETM+ images. To remove the biasness of the images, some pre-processing techniques like stream ordering, band differencing, colour texturing were employed to enhance the edges of the structural features. Extracted lineaments and its distribution and orientation were mapped using ArcGIS Spatial analyst tool. Results of the study showed maximum number of lineaments were oriented in the ENE–SWS direction with 63° overall inclination. Accuracy assessment and validation were made with respect to visual interpretation and overlaying the lineament on Digital Topographic Model as well as with respect to an existing geological lineament map of the study site. The result of accuracy assessment indicates higher compatibility of Central Indian Suture with the geological map of the study area.     

Efficiency Evaluating of Automatic Lineament Extraction by Means of Remote Sensing (Case Study: Venarch,Iran)

One of the main geological evidence for many ore-bearing deposits and mineralized regions is the existence of points in highly fractured zones and the fragmentation intensity resulted from development of hydrothermal alteration along the fractures, the process leading to the occurrence of ore deposits. In this paper, a new algorithm has been proposed including a set of image processing techniques for detection the lineaments in satellite images by means of programming in MATLAB environment. The set of utilized methods includes line segment extraction by EDLine algorithm, merging line segments by Tavares method and linking the resulting line segments based on the collinearity and proximity criterion. The tectonic structures were stabilized by B-Spline curve fitting. The proposed algorithms were implemented on the ASTER image of a structurally multiple fractured region located in the central Iran, and the lineament map of Venarch area has been depicted. The results obtained from the proposed algorithms indicate a high accuracy of the operations detection of 80% for the reference map lineaments and the overall accuracy of the method is effectively reported as 62%. Combination of the above algorithms proposes a new method that precisely resulted in obtaining image processing of geological evidence for increasing the accuracy and decreasing the risk, before any field operations.     

辽河盆地及其邻区遥感图像的石油地质分析

通过对不同种类、不同波段及不同处理方法所获得图像的分析表明, 一种卫片组合图像处理 方法, 即线性拉伸-直方圆调整-局部增强-彩色级上色所产生的图像, 对了解辽河盆地前第三 系基底起伏状况及其结构特点具有良好效果。 地质解译分析肯定了北东(含北北东)向线性构造的主导作用, 但同时遥感信息强烈地反映 了北西向线性构造对盆地构造格架的影响。地质解译还表明, 辽河盆地的环形影像具有两个明显 特点:(1)浅色影像以反映正向构造为主;(2)深色影像以反映负向构造为主, 而已知油田在 标准假彩色图像上也具有明亮的浅色圆形或块状影像特征。因此, 可结合其它地质资料的综合分 析, 以类比方法来预测新的油气田。     

Statistical analysis and tectonic interpretation of the remotely sensed lineament fabric data associated with the North Almora Thrust,Garhwal Himalaya,India

A geostatistical analysis of the remotely-sensed lineament fabric data associated with the North Almora Thrust of Garhwal Himalaya has been carried out The analysis of data provided 18 major orientations of the lineament density girdles. Further statistical treatment of these derived lineaments using the method of analysts of directional data indicates that the lineaments can be classified into genetic groups. The result indicates that the North Almora Thrust and Kaliasaur Fault are not genetically related and occurred in separate phases of tectonic activities. The results also show that the Alaknanda river is flowing through a tectonically-controlled valley. The study suggests the suitability of statistical methods in lineament-fabric-data analysis for tectonic interpretations.     

Basement reactivation and its relation to neotectonic activity in and around Allahabad, ganga plain

The study of lineament pattern based on IRS-IA sub-scene (P24–R50) and Landsat (P143– R42) data combined with the drainage analysis and field observations, two prominent sets of lineament (NE-SW and NNW-SSE), besides less prominent E-W and N-S trending lineaments of tectonic origin have been observed in parts of Allahabad area. Pervasive and penetrative sub-vertical joint sets parallel to the macroscopic linear structures along with collapse structures possibly of neotectonic origin are also noted in the basement rock exposed to the SSW of Allahabad. The development of various meso- and macroscopic deformed structures, presence of collapse structure in the basement strata and the near orthogonal channel shift of axial rivers provide evidence of basement reactivation in parts of Allahabad area, Ganga plain in space and time.     

Thrust controlled lineaments of the Aravalli-Delhi fold Belt, Rajasthan, India mapped from landsat TM image

The litho-units of the area between Chawand to Kotra across the Aravalli-Delhi Fold Belt are referable to Bhilwara, Aravalli and and Delhi Supergroups. Earlier workers considered the sequence as progressively younger toward west across the Avavalli Orographic axis. Two-dimensional trend mapping of the planar tectonic anisotropy was carried out to map lineaments from landsat TM Image. Ground checks of the lineament along Chawand-Kotra section suggest that lineaments are tectonic dislocations, morphotectonically controlled by thrusts and ductile shears within the Aravalli-Delhi Fold Belt. The recognition of thrust bounded litho-tectonic units from interpretation of satellite remotely sensed data may necessitate reassessment of the Precambrian lithostraligraphy of the Aravalli and Delhi supergroups in the study area. The paper reports thrust tectonics from Aravalli-Delhi Fold Bell. The Antalia Schuppean Belt is possible duplex; imbricate thrusts are connected with base thrust and continuity with roof thrust has been punctuated by transverse faulting and erosion.