基于半监督鉴别分析的高分辨率SAR影像建筑区提取

针对建筑物在城市化发展规划、地理国情信息系统更新、数字化城市以及军事侦察等方面的迫切要求,提出将半监督鉴别分析(Semi-supervised Discriminant Analysis,SDA)算法应用于高分辨率SAR影像的建筑区提取中,实现快速提取建筑区信息以及提高城市地物目标识别能力。以Radarsat-2影像和TerraSAR-X影像为实验数据,基于灰度共生矩阵计算影像的各种纹理特征;结合SDA算法进行特征提取,并以新特征作为大津法(Otsu)的输入提取建筑区;最后对分类结果进行后处理。实验结果与线性鉴别分析(Linear Discriminant Analysis,LDA)算法和局部保持投影(Local Preserving Projection,LPP)算法进行比较,结果表明:SDA算法具有较强的泛化能力,在先验类别信息较少时,适用于高分辨率SAR影像的特征提取,可以快速有效地提取建筑区信息。     

基于高分辨率遥感影像的城市建筑容积率估算方法研究--上海市中心城区为例

在总结目前常用的建筑容积率估算方法基础上,以高分辨率遥感影像为数据基础,提出了一种新的、适用于大范围建筑容积率估算的方法--阴影面积法.以上海市中心城区为例,详细阐述了阴影面积法在图像处理软件及GIS技术支撑下的实施方案.对估算中可能产生的问题以及估算精度进行了分析.实验表明阴影面积法对大都市区的建筑容积率估算具有速度快、效率高的特点,基本能够满足中尺度大都市空间建设动态监测的需要.     

基于高分辨率遥感影像的城市建筑容积率估算方法研究——以上海市中心城区为例

在总结目前常用的建筑容积率估算方法基础上，以高分辨率遥感影像为数据基础，提出了一种新的、适用于大范围建筑容积率估算的方法——阴影面积法。以上海市中心城区为例，详细阐述了阴影面积法在图像处理软件及GIS技术支撑下的实施方案。对估算中可能产生的问题以及估算精度进行了分析。实验表明：阴影面积法对大都市区的建筑容积率估算具有速度快、效率高的特点，基本能够满足中尺度大都市空间建设动态监测的需要。     

基于高分辨率遥感影像的土地覆盖信息提取

高空间分辨率遥感影像使得土地覆盖和土地利用信息的提取成为可能。以高分辨率遥感影像数据IKONOS为主要数据源,以多尺度分割与基于模糊逻辑分类的面向对象影像分析方法为主要技术,自动提取株洲市城乡结合部的土地覆盖和土地利用信息。达到了提取郊区丘陵地带林地信息和城市建筑、道路等土地覆盖信息的目的,而且精度高,速度快。结果表明利用该方法对复杂的城乡结合部信息获取是可行的。     

合肥主城区建筑密度的珞珈一号夜光影像估算

建筑密度是城市规划、土地管理和居住区环境评估的重要指标。相比传统夜光遥感,珞珈一号具有更高的空间分辨率,在城市建筑密度估算方面更有优势。基于珞珈一号数据源,以合肥市主城区为实验区,以1km×1km范围为统计单元,将样区夜光影像灰度值进行灯光强度分类,同时结合人工数字化建筑物基地进行拟合分析。引入均值迁移、形态学等方法,排除道路灯光对估算结果的干扰;通过建立建筑密度估算模型,最终得到合肥市主城区的建筑密度空间分布结果,并对结果进行交叉验证。结果表明,在建筑密度估算方面,珞珈一号夜光遥感影像具有较高的估算建筑密度能力,未来在其他社会经济数据空间分析方面也具有巨大潜力。     

联合快舟一号影像纹理信息的城市土地覆盖分类

仅依靠光谱信息无法满足高分辨率遥感分类的应用需求,辅之以纹理特征信息进行分类,可提高影像分类精度。利用KZ\|1卫星影像和Landsat\|8卫星影像数据,基于面向对象的影像分割法和灰度共生矩阵纹理分析法对新疆石河子市局部城区进行了地表覆盖分类实验,将不同空间分辨率的全色影像纹理信息、光谱信息构成多种影像特征组合进行分类比较研究,以选择最佳的分类特征集。结果表明:KZ-1影像能为城市区域的土地覆盖分类提供丰富的纹理信息,面向对象的影像分割可较好地利用高分辨率数据的几何结构信息实现优化的影像分割,从而提高多光谱影像的分类精度,总体分类精度为90.06%,Kappa系数为87.93%,比单纯利用光谱信息分类的总体精度提高了8.02%,Kappa系数提高了9.65%,表明KZ\|1数据可为光谱分类提供丰富的纹理信息,从而提高城市区域的土地覆盖分类精度。     

基于遗传算法的建筑容积率优化研究与设计

为了自动确定拟建建筑的容积率,提出一种基于遗传算法的最大容积率计算方法,并设计出一套实用软件。求解拟建建筑最佳容积率,是一个NP问题,遗传算法是一种进化优化算法,能够有效地解决这种NP优化问题。所提方法首先计算太阳高度角;然后,由太阳高度角和其他参数,计算拟建建筑的棒影长度;最后,基于日照约束条件,采用遗传算法自动计算拟建建筑的最佳高度,从而进一步计算最佳容积率。满足日照最低要求计算建筑的最佳高度是软件的核心技术。在建筑申报前计算出该地块的建筑最佳高度,进一步计算日照约束下的最大容积率。在建筑申报前,该系统能够计算出地块建筑最佳容积率,提高了建筑设计的科学性和便捷性,也为建筑行业设计提供一种良好设计方法。     

高分辨率影像中基于纹理的建筑区信息提取

在分析QuickBird高分辨率遥感影像特点的基础上,将纹理特征作为分类依据,通过对比实验得出参与分类计算的纹理特征参数为反差和增强反差,按标准距离选出最佳分类因子。选取绿色波段数据,使用改进的最小距离法自动提取影像中的建筑区信息。仿真结果表明,基于该方法提取的建筑区信息识别率为95.4%。     

基于对象的最优尺度建筑物信息提取方法

针对基于像素分析方法不适用于高分辨率影像信息提取的问题,提出一种基于对象的图像分析方法来进行城市建筑信息提取。采用多分辨率图像分割方法得到图像对象,提出非监督的最优尺度判定方法解决单尺度分割造成的欠分割和过分割问题。在对象分类提取过程中,结合LiDAR数据的地形表面高程信息和光谱信息对建筑物进行提取,并利用尺寸、空间位置等信息进行误分类修正。实验区域共提取出18个建筑目标,结果表明所提出的方法有效可行。     

纹理与几何特征在道路提取中的应用

提出一种利用纹理与几何特征的高分辨率遥感影像道路提取方法。首先分析高分辨率遥感影像的纹理特征,提出基于纹理特征的聚类方法,将影像大致分为道路区域和非道路区域,然后选取适当的几何特征指数,剔除道路区域中含有的非道路像素,得到初步道路信息。最后通过数学形态学处理,去除初步道路信息中由于车道线、树木影响而产生的孔洞,最后得到完整的道路信息。实验结果表明,与传统方法相比,该方法能够有效地从高分辨率遥感影像中提取道路。     

Incorporating nocturnal UAV side-view images with VIIRS data for accurate population estimation: a test at the urban administrative district scale

ABSTRACT

In contrast to daytime remote sensing used for observing the Earth, night-time light remote sensing with satellites primarily assesses human activity using urban parameters such as building lights or lighted highways to help determine population density and other habitation characteristics. One limitation to conventional night-time remote sensing is that light emitted from high-rise buildings, for example, is not easily detected because of optical geometry as satellite sensors are generally pointed in only a downward direction. Furthermore, satellite sensors often receive weak optical signals because of streetlights reflected from the Earth’s surface. As a result, accurate information on night-time human activity cannot be gathered from existing satellite remote-sensing methods. To address this, a new method for night-time remote setting is presented. Specifically, an unmanned aerial vehicle (UAV) is used to capture panoramic images of night-time light and processed to reveal side-view light spot information from urban buildings. This dataset was used to predict population density alone, and with the Visible Infrared Imaging Radiometer Suite (VIIRS) data by simple multiple linear regression. The results confirm that nocturnal UAV side-view data or VIIRS data alone can be used to estimate population density, while the combination of the two significantly increases the accuracy of population density estimation compared against estimating population density using nocturnal UAV side-view data or VIIRS data alone. This outcome suggests that multi-angular night-time remote-sensing data sources increase the accuracy of urban population density estimation. One reason for this may be that the side-view night-time data and orthophoto data infer urban population density from different agent variables: building occupancy is a proxy of side-view night-time data, while density of illuminated road network is that of orthophoto data.     

高分辨率多光谱遥感影像中城区道路信息的自动提取

提出一种从高分辨率遥感影像提取城市区域道路网络的方法。该方法采用改进的数学形态学运算方法对影像进行分割,进而得到粗略道路信息网,然后利用道路网的几何特征实现道路与建筑物的有效区分,最后通过抽骨架的方法获得最终道路网中心线。试验数据为某一城区高分辨率卫星影像,并对最终提取的结果进行了评价,结果表明,所提出的方法能够从高分辨率多波段卫星遥感影像上精确、有效、自动提取城区道路网络。     

Characterizing the impact of urban morphology heterogeneity on land surface temperature in Guangzhou,China

The urban morphology is regarded as one of the main reasons for urban heat island (UHI). However, its effect on UHI in city-scale urban areas has seldom been examined. In this paper, we presented a rule-based regression model for investigating the nonlinear relationship between land surface temperature (LST) and urban morphology represented by building height, building density and sky view factor (SVF) across different dates in 2005. Results found that an urban morphology of medium building height and lower density significantly yielded higher LST variation levels, whereas the lowest LST variation levels occurred in high-rise and high-dense building arrays. Compared to building height, building density had a stronger influence on LST. Medium SVF values produced the lowest LST, whereas the largest and smallest SVF values produced the highest LST. Results also showed how rule-based regression model offer great performance in detecting the nonlinear mechanisms of LST as well.     

Building Height Estimation from GF-2 Image based on Morphological Shadow Index

GF-2 is a high resolution earth observing satellite with sub\|meter resolution which is developed by our own technique.To estimate urban building height based on GF\|2 remote sensing image combined with the idea of mathematical morphology and object\|oriented classification.First of all,segment image based on multi\|scale segmentation.Then extract shadow and calculate its length based on object\|oriented classification combined with spectral,shape,Morphological Shadow Index (MSI) and other features.In the end,estimate building height based on the geometrical model of satellite,sun and building and then accuracy evaluation and error analysis are carried out by using the field measurement data.Experimental results showed that 90% of the buildings’ absolute error is less than 1 m.This experiment demonstrate that the method can extract the height of urban building from the GF\|2 image effectively and the immense potential of domestic high resolution remote sensing image in applications on urban building information extraction.     

国内外卫星通信技术的新进展

80年代以来,世界各地卫星通信突飞猛进地发展,在国民经济、国防建设以及现代战争中起了非常重要的作用,如卫星电视、卫星电话、卫星气象云图以及火灾监测、遥感遥测和用于军事方面的高空侦察。近几年一种被称为GPS的定位跟踪系统也日臻完善,并且向民用导航方面发展。本文主要介绍国内外卫星通信技术的新进展。     

Estimating parameters of a two-layer stratified ocean from polarity conversion of internal solitary waves observed in satellite SAR images

This paper presents a method for estimating parameters of a two-layer stratified ocean using satellite SAR images. According to weak nonlinearity shallow water theory, internal solitary waves (ISWs) in stratified oceans may be either depression or elevation waves, depending on the sign of the quadratic nonlinearity coefficient in the KdV equation. It has been confirmed that ISWs can convert their polarity when passing through a turning point, where the quadratic nonlinearity coefficient changes sign. For a two-layer stratified ocean, the turning point is located where the upper and lower layer depths are equal. The authors suggest that depression, elevation and broadening ISWs can be discerned according to their different signatures in SAR images. It is also found that a SAR image can record a continuous evolution process from depression to elevation ISWs in its spatial domain, under conditions of a spatially inhomogeneous ocean environment. Therefore, the upper and lower layer depths can be calculated by determining the polarity conversion of ISWs observed in satellite SAR images. Furthermore, the density difference between the upper and lower layers can also be estimated, when the wave speed is known. We extract ocean stratification parameters, including upper layer depth and density difference, from polarity conversion of ISWs observed in a RADARSAT-1 SAR image taken over the northeastern South China Sea. Comparing the estimated results with field measurements, we find that this method can estimate the upper layer depth with considerable success. In estimating the density difference between the upper and lower layers, it also gives a quite reasonable result.     

The automatic height extraction of buildings from shadow region

Height extraction for buildings is a fundamental step of 3D scene reconstruction in many virtual reality applications.In this paper,we propose an automatic method to extract the height of buildings in high resolution satellite imagery based on the length of shadow.Taking into account the limitation of traditional algorithms,we make use of the boundary information of a building to facilitate detecting and matching the shadow regions with higher accuracy.Then,we introduce a shadow-cast model to correct the shadow location in our system.The experimental result shows that when extracting the height of buildings from complex urban regions,our method has better accuracy.     

滨海新区本土文化与城市形象设计模式研究

信息时代,科学技术的普及应用,城市环境形象也发生着变化。城市的发展离不开城市建设,城市经济、政治、文化以及环境等多种因素均见证着该城市的成长历程,如何建设适宜人居住的城市环境形象是当今时代诸多城市规划部门要考虑的首要前提,什么样的城市给人能留下深刻的印象。特色环境形象建设是第一要务。     

Comparative Study on Thermal Environment between Old Urban Areas and New Urban Areas based on Landsat 8 Remote Sensing Image：A Case Study of Chengdu City

A large number of new urban areas have emerged under the rapid urbanization background in recent years in China，and the characteristics of urban thermal environment have significant changes.To analyze the thermal environment diversities between old urban areas and new urban areas and explore the impacting factors，we chose Chengdu City in Sichuan Province as a typical study area.Key surface parameters，including Land Surface Temperature (LST)，building index and vegetation index were derived based on Landsat 8 satellite image acquired on August 13，2014.The comparison study was conducted to analyze the differences of the parameters related to thermal environment changes，and the results indicated that：①Overall,the average surface temperature of the old urban area was higher than that of the new urban area.Regarding the spatial distribution，the central and northern region had higher temperature than the southern region for the old urban areas.In the new urban areas，although high temperature spots can be found in the central west or north，this region generally had a relatively low temperature.②The old urban area emphasized a higher Urban\|Heat\|Island\|Ratio\|Index (URI)，which revealed the descending trend of surface temperature via analyzing the thermal field profile from the old to the new.This showed that the urban thermal environment effect of the old city was stronger than the new urban area.③“Heat Island Effect” was easy to emerge in those areas with high density urban construction and little urban vegetation coverage，whereas reasonable urban landscape planning and layout would help to perfect the urban thermal environment.The comparison of the thermal environment effects between the new urban areas and the old urban areas shows the new urban planning in Chengdu has positively contributed to improve the thermal environment in the new urban areas，which can provide important reference for the future urban planning.