Retrieval of High Resolution Satellite Images Using Texture Features

In this research, a content-based image retrieval （CBIR） system for high resolution satellite images has been developed by using texture features. The proposed approach uses the local binary pattern （LBP） texture feature and a block based scheme. The query and database images are divided into equally sized blocks, from which LBP histograms are extracted. The block histograms are then compared by using the Chi-square distance. Experimental results show that the LBP representation provides a powerful tool for high resolution satellite images （HRSI） retrieval.

Integrating cross-sensor high spatial resolution satellite images to detect subtle forest vegetation change in the Purple Mountains,a national scenic spot in Nanjing,China

Accurate information on the location and magnitude of vegetation change in scenic areas can guide the configuration of tourism facilities and the formulation of vegetation protection measures.High spatial resolution remote sensing images can be used to detect subtle vegetation changes.The major objective of this study was to map and quantify forest vegetation changes in a national scenic location,the Purple Mountains of Nanjing,China,using multi-temporal cross-sensor high spatial resolution satellite images to identify the main drivers of the vegetation changes and provide a reference for sustainable management.We used Quickbird images acquired in 2004,IKONOS images acquired in 2009,and WorldView2 images acquired in 2015.Four pixel-based direct change detection methods including the normalized difference vegetation index difference method,multi-index integrated change analysis(MIICA),principal component analysis,and spectral gradient difference analysis were compared in terms of their change detection performances.Subsequently,the best pixel-based detection method in conjunction with object-oriented image analysis was used to extract subtle forest vegetation changes.An accuracy assessment using the stratified random sampling points was conducted to evaluate the performance of the change detection results.The results showed that the MIICA method was the best pixel-based change detection method.And the object-oriented MIICA with an overall accuracy of 0.907 and a kappa coefficient of 0.846 was superior to the pixel-based MIICA.From 2004 to 2009,areas of vegetation gain mainly occurred around the periphery of the study area,while areas of vegetation loss were observed in the interior and along the boundary of the study area due to construction activities,which contributed to 79%of the total area of vegetation loss.During 2009–2015,the greening initiatives around the construction areas increased the forest vegetation coverage,accounting for 84%of the total area of vegetation gain.In spite of this,vegetation loss occurred in the interior of the Purple Mountains due to infrastructure development that caused conversion from vegetation to impervious areas.We recommend that:(1)a local multi-agency team inspect and assess law enforcement regarding natural resource utilization;and(2)strengthen environmental awareness education.

Research on High Resolution Satellite Image Classification Algorithm based on Convolution Neural Network

Artifi cial neural network is a kind of artificial intelligence method to simulate the function of human brain, and deep learning technology can establish a depth network model with hierarchical structure on the basis of artificial neural network. Deep learning brings new development direction to artificial neural network. Convolution neural network is a new artificial neural network method, which combines artificial neural network and deep learning technology, and this new neural network is widely used in many fields of computer vision. Modern image recognition algorithm requires classifi cation system to adapt to different types of tasks, and deep network and convolution neural network is a hot research topic in neural networks. According to the characteristics of satellite digital image, we use the convolution neural network to classify the image, which combines texture features with spectral features. The experimental results show that the convolution neural network algorithm can effectively classify the image.

Level study on fractal characteristics of tidal creeks and information of seashell habitats in the Gaizhou Beach based on high-resolution satellite images

The fractal characteristics of tidal creeks in the Gaizhou Beach are analyzed based on high-resolution images fusionof Landsat TM and ERS2, and then the graphic models and characteristics of converse information tree of tidalcreeks in the Gaizhou Beach are established. A calculation model is established based on the above results, and at thesame time, quantitative calculation of the evolution characteristics and the diversity between the northern and thesouthern parts of the Gaizhou Beach is carried out. By the supervised classification of these images, distribution andareas of high tidal flats, middle tidal flats and low tidal flats in the Gaizhou Beach are studied quantitatively, and imagecharactistics of seashell habitats in the Gaizhou Beach and the correlation between mudflat distribution and seashellhabitats are studied. At last, the engineering problems in the Gaizhou Beach are discussed.

Geometric Calibration and Image Quality Assessment of High Resolution Dual-Camera Satellite

The evaluation of geometric calibration accuracy of high resolution satellite images has been increasingly recognized in recent years.In order to evaluate geometric accuracy for dual-camera satellite images based on the ground control points(GCP),a rigorous geometric imaging model,which was based on the collinear equation of the probe directional angle and the optimized tri-axial attitude determination(TRIAD)algorithm,is presented.Two reliable test fields in Tianjin and Jinan(China)were utilized for geometric accuracy validation of Pakistan Remote Sensing Satellite-1.The experimental results demonstrate a certain deviation of the on-orbit calibration result from the initial design values of the calibration parameters.Therefore,on-orbit geometric calibration is necessary for optical satellite imagery.Within this research,the geometrical performances including positioning accuracy without/with GCP and band registration of the dual-camera satellite were analyzed in detail,and the results of geometric image quality are assessed and discussed.As a result,it is feasible and necessary to establish such a geometric calibration model to evaluate the geometric quality of dual-camera satellite.

Intelligent High Resolution Satellite/Aerial Imagery

High resolution satellite images are rich source of geospatial information. Nowadays, these images contain finest spectral and spatial information of ground realities in different electromagnetic spectrum. Many image processing softwares, algorithms and techniques are available to extract such information from these images. Multi spectral as well as panchromatic (PAN) high resolution satellite images are missing, one important information, regarding ground features and realities that information is attribute information which is not directly available in high resolution satellite images. From very first day, this information used to be collected through indirect ways using GPS, digitizing, geo-coding, geo tagging, field survey and many other techniques. Our real world has vertical labels for ground observer to identify and use this information. These vertical labels are present in form of names, logos, icons, symbols and numbers. These vertical labels ease us to work in real world. Satellites are unable to read these labels due to their vertical orientation. Making satellite/aerial imagery rich of attribute information, we have the possibility to design our world accordingly. Just like vertical labels we can also place real physical horizontal label for space sensors, to make this information directly available in high resolution satellite/aerial imagery. This work is about possibilities of such techniques and methods.

An Integrated Framework for Road Detection in Dense Urban Area from High-Resolution Satellite Imagery and Lidar Data

Automatic road detection, in dense urban areas, is a challenging application in the remote sensing community. This is mainly because of physical and geometrical variations of road pixels, their spectral similarity to other features such as buildings, parking lots and sidewalks, and the obstruction by vehicles and trees. These problems are real obstacles in precise detection and identification of urban roads from high-resolution satellite imagery. One of the promising strategies to deal with this problem is using multi-sensors data to reduce the uncertainties of detection. In this paper, an integrated object-based analysis framework was developed for detecting and extracting various types of urban roads from high-resolution optical images and Lidar data. The proposed method is designed and implemented using a rule-oriented approach based on a masking strategy. The overall accuracy (OA) of the final road map was 89.2%, and the kappa coefficient of agreement was 0.83, which show the efficiency and performance of the method in different conditions and interclass noises. The results also demonstrate the high capability of this object-based method in simultaneous identification of a wide variety of road elements in complex urban areas using both high-resolution satellite images and Lidar data.

Estimating aboveground biomass using Pléiades satellite image in a karst watershed of Guizhou Province,Southwestern China

Biomass in karst terrain has rarely been measured because the steep mountainous limestone terrain has limited the ability to sample woody plants.Satellite observation, especially at high spatial resolution, is an important surrogate for the quantification of the biomass of karst forests and shrublands. In this study, an artificial neural network(ANN) model was built using Pléiades satellite imagery and field biomass measurements to estimate the aboveground biomass(AGB) in the Houzhai River Watershed, which is a typical plateau karst basin in Central Guizhou Province, Southwestern China. A back-propagation ANN model was also developed.Seven vegetation indices, two spectral bands of Pléiades imagery, one geomorphological parameter,and land use/land cover were selected as model inputs. AGB was chosen as an output. The AGB estimated by the allometric functions in 78 quadrats was utilized as training data(54 quadrats, 70%),validation data(12 quadrats, 15%), and testing data(12 quadrats, 15%). Data-model comparison showed that the ANN model performed well with an absolute root mean square error of 11.85 t/ha, which was 9.88%of the average AGB. Based on the newly developed ANN model, an AGB map of the Houzhai River Watershed was produced. The average predicted AGB of the secondary evergreen and deciduous broadleaved mixed forest, which is the dominant forest type in the watershed, was 120.57 t/ha. The average AGBs of the large distributed shrubland,tussock, and farmland were 38.27, 9.76, and 11.69 t/ha, respectively. The spatial distribution pattern ofthe AGB estimated by the new ANN model in the karst basin was consistent with that of the field investigation. The model can be used to estimate the regional AGB of karst landscapes that are distributed widely over the Yun-Gui Plateau.

Optimization of post-classification processing of high-resolution satellite image:A case study

The application of remote sensing monitoring techniques plays a crucial role in evaluating and governing the vast amount of ecological construction projects in China. However, extracting information of ecological engineering target through high-resolution satellite image is arduous due to the unique topography and complicated spatial pattern on the Loess Plateau of China. As a result, enhancing classification accuracy is a huge challenge to high-resolution image processing techniques. Image processing techniques have a definitive effect on image properties and the selection of different parameters may change the final classification accuracy during post-classification processing. The common method of eliminating noise and smoothing image is majority filtering. However, the filter function may modify the original classified image and the final accuracy. The aim of this study is to develop an efficient and accurate post-processing technique for acquiring information of soil and water conservation engineering, on the Loess Plateau of China, using SPOT image with 2.5 rn resolution. We argue that it is vital to optimize satellite image filtering parameters for special areas and purposes, which focus on monitoring ecological construction projects. We want to know how image filtering influences final classified results and which filtering kernel is optimum. The study design used a series of window sizes to filter the original classified image, and then assess the accuracy of each output map and image quality. We measured the relationship between filtering window size and classification accuracy, and optimized the post-processing techniques of SPOT5satellite images. We conclude that (1) smoothing with the majority filter is sensitive to the information accuracy of soil and water conservation engineering, and (2) for SPOT5 2.5 m image, the 5×5 pixel majority filter is most suitable kernel for extracting information of ecological construction sites in the Loess Plateau of China.

Improving georeferencing accuracy of Very High Resolution satellite imagery using freely available ancillary data at global coverage

While impressive direct geolocation accuracies better than 5.0 m CE90(90%of circular error)can be achieved from the last DigitalGlobe’s Very High Resolution(VHR)satellites(i.e.GeoEye-1 and WorldView-1/2/3/4),it is insufficient for many precise geodetic applications.For these sensors,the best horizontal geopositioning accuracies(around 0.55 m CE90)can be attained by using third-order 3D rational functions with vendor’s rational polynomial coefficients data refined by a zero-order polynomial adjustment obtained from a small number of very accurate ground control points(GCPs).However,these high-quality GCPs are not always available.In this work,two different approaches for improving the initial direct geolocation accuracy of VHR satellite imagery are proposed.Both of them are based on the extraction of three-dimensional GCPs from freely available ancillary data at global coverage such as multi-temporal information of Google Earth and the Shuttle Radar Topography Mission 30 m digital elevation model.The application of these approaches on WorldView-2 and GeoEye-1 stereo pairs over two different study sites proved to improve the horizontal direct geolocation accuracy values around of 75%.

大气湍流对高分辨率遥感卫星的成像影响研究

遥感卫星在国防和民用探测等领域发挥着重要作用,而大气湍流严重影响高分辨率遥感卫星的成像质量。本文重点研究了遥感卫星对地探测时,相机口径、卫星轨高和大气湍流强度对空间相机成像质量的影响。首先,基于球面波传输模型和Kolmogorov湍流理论,针对空对地探测湍流波前进行仿真。然后,分析畸变波前随相机口径、卫星轨高和大气相干长度的变化规律,并推导出普适公式。在此基础上,进一步推导出空间相机成像分辨率随相机口径、卫星轨高和大气相干长度变化的计算公式。最后,研究了大气湍流对空间相机调制传递函数(MTF)的影响,并以MTF=0.15为基准,仿真分析了MTF相对误差随相机口径、卫星轨高和大气相干长度的变化规律。本研究为高分辨率遥感卫星的设计、分析和评估提供理论依据。

量子多尺度融合的高分卫星影像建筑物变化检测

为了提高传统基于像元的高分辨率卫星影像变化检测方法的精度,本文提出了一种基于量子多尺度融合的高分卫星影像建筑物变化检测算法。首先,对双时相高分辨率卫星影像进行多尺度分割,构成多尺度影像数据集;然后,对多尺度影像数据集进行迭代慢特征变换,得到不同尺度的变化强度图,再利用量子理论对多尺度变化强度图进行融合,以得到融合后的变化强度图;最后,通过最大类间方差法完成变化强度图的阈值分割,得到二值化变化检测结果。利用两组不同时相的实际高分卫星影像,对本文算法进行了试验验证。试验结果表明,与单一尺度面向对象变化检测方法和熵权法多尺度融合方法相比,本文算法可以取得更高的建筑物变化检测精度。

美军空间侦察发展现状与趋势分析

空间侦察已经成为现代化作战体系的重要一环,是获取高技术战争制信息权继而掌握战场主动权的关键。以美军空间侦察体系为例,从空间光学成像侦察体系、空间雷达成像侦察体系、定轨空间信号侦察体系、变轨空间信号侦察体系等方面梳理其发展现状。结合美军运用实例,从中心网络、平战转换、联合监视、预先侦察4个方面分析其技术运用。从异构侦察网络协同技术、情报数据高速传输技术、高分辨率穿透成像技术、高精度目标定位技术4方面总结美军空间侦察关键技术。最后,从空间侦察卫星小型化、侦察网络平战联合化、侦察体系抗扰抗毁化、侦察情报一体共享化、情报处理决策智能化5个角度分析空间侦察发展趋势,为未来空间侦察体系建设、运用与发展提供参考。

基于人工智能的多源遥感数据融合在电网勘测应用研究

随着卫星遥感、空间科技等技术的不断发展,通过卫星采集多源遥感数据已被广泛应用到诸多行业。将多源数据进行融合,生成信息更丰富、质量更高的图像,能更清晰地分析地物地貌地形情况,已成为近年来图像智能处理领域的技术研究前沿方向。文章基于人工智能卷积网络和注意力机制,提出一种统一融合网络,将不同光谱和空间属性的遥感源数据进行有效融合,生成具有精确光谱信息和清晰空间细节的高分辨率图像,为电网勘测选址选线等业务提供了辅助支撑的有效手段。实验结果表明,文章研究结果比现有典型方法具备更好的融合效果。

基于高分卫星影像的湖南某地土地利用分类研究

随着遥感技术的快速发展,越来越多高分辨率遥感影像的出现,为快速准确地获取地面信息创造了有利条件。面向对象的分类方法在进行地物信息提取时,考虑了更多的分类特征,且能与地学知识以及其他专题特征相结合,使分类过程与人类的认知过程更加接近,已成为土地利用信息提取研究的主流方向之一。研究以高分二号影像为基础,探索多尺度分割最优参数的选取方法,构建了影像分类特征空间并对其进行优化。基于多层次分类体系提取土地利用信息,并进行精度评价。通过空间大数据对建设用地信息进行细分,并对其空间分布特征进行分析。

高分立体卫星影像建设基础三维模型研究

实景三维中国建设总体实施方案提出,截至2025年要建成覆盖地级以上城市城镇开发边界范围的基础三维模型数据。为提高实景三维中国基础三维模型数据生产效率,本文基于高分立体卫星影像精准定向精化的RPC参数构建立体模型并生成精准几何信息的DSM、DEM、DOM成果,对全立测采集、基于DOM采集等不同技术方法获取的建筑轮廓以及立测、基于DEM/DSM获取的高程高度信息等精度差异进行了分析,并以哈尔滨市为试验区,验证了基于高分立体卫星影像大规模生产基础三维模型数据的技术路线及可行性。

基于大数据分析的高分辨率可见光遥感卫星影像解译能力评估

高分辨率可见光遥感卫星影像应用范围的不断扩大,对其解译能力提出了更高的要求。为了能够选取最佳的遥感卫星影像解译技术,需要对解译能力进行精准的评估与判断。本文结合海量影像数据,进行基于大数据分析的高分辨率可见光遥感卫星影像解译能力评估研究。深入分析遥感卫星影像解译能力影响因素,以此为基础,联合遥感卫星影像解译实际情况,选取适当的解译能力评估指标,应用大数据分析技术—模糊C均值(FCM)聚类算法对指标数据进行分类处理及其分析,基于熵权法计算解译能力评估指标的权重系数,结合当前解译能力评估指标数值,采用加权求和方法计算遥感卫星影像解译能力综合评估数值,从而实现了遥感卫星影像解译能力的有效评估。实验结果显示:应用该方法获得的遥感卫星影像解译能力评估时间最小值为16 s,解译能力评估结果与实际结果保持一致,充分证实了该方法解译能力评估性能较佳。

基于不同数据源类型构建LOD1.3级城市三维模型相关技术研究

为探索基于不同数据源类型构建LOD1.3级城市三维模型相关技术,本文以黑龙江省伊春市主城区为研究对象,通过三维模型构建技术路线、构建内容、构建方法的对比等方面进行相关的技术研究。

浅谈地形级实景三维生产中的问题分析及处理

近年来卫星遥感技术高速发展,高分辨率卫星立体像对广泛应用于智慧城市、环境监测、灾害评估、农业监测、气候变化、实景三维建设等领域。本文以吉林省地形级实景三维建设试验区为例,将利用高分辨率卫星立体像对进行地形级实景三维生产方法及3D产品(DEM、DSM、DOM)分析总结,从生产技术方法角度,阐述了地形级实景三维生产任务、内容要求、生产工作流程和技术方法,针对生产中出现的问题提出解决方案,具有一定的参考价值。

高分辨率卫星影像图面质量问题排查及处理流程

图面质量问题排查及处理是数字正射影像生产必不可少的环节。优化问题排查与处理流程,对规范作业方式、提高作业效率、提升影像成果质量具有重要作用。本文首先通过分析、归纳常见图面质量问题类型,创建问题模板,开展图面质量问题排查;然后对问题进行区域综合,根据区域综合结果进行影像分块,并对分块影像进行修改;最后将问题转为PS软件注释,通过切换注释实现问题区域的自动定位。实践结果表明,基于问题模板进行图面质量问题排查,能够规范作业方式,提高成果的一致性;问题区域综合后分块修改影像问题,能够提高影像读写速度,符合多人多机并行作业的生产模式;问题区域自动定位与跳转,能够提高图面质量问题修改效率。