Automatic extraction of building roofs using LIDAR data and multispectral imagery     

《ISPRS Journal of Photogrammetry and Remote Sensing》2013

Automatic 3D extraction of building roofs from remotely sensed data is important for many applications including city modelling. This paper proposes a new method for automatic 3D roof extraction through an effective integration of LIDAR (Light Detection And Ranging) data and multispectral orthoimagery. Using the ground height from a DEM (Digital Elevation Model), the raw LIDAR points are separated into two groups. The first group contains the ground points that are exploited to constitute a ‘ground mask’. The second group contains the non-ground points which are segmented using an innovative image line guided segmentation technique to extract the roof planes. The image lines are extracted from the grey-scale version of the orthoimage and then classified into several classes such as ‘ground’, ‘tree’, ‘roof edge’ and ‘roof ridge’ using the ground mask and colour and texture information from the orthoimagery. During segmentation of the non-ground LIDAR points, the lines from the latter two classes are used as baselines to locate the nearby LIDAR points of the neighbouring planes. For each plane a robust seed region is thereby defined using the nearby non-ground LIDAR points of a baseline and this region is iteratively grown to extract the complete roof plane. Finally, a newly proposed rule-based procedure is applied to remove planes constructed on trees. Experimental results show that the proposed method can successfully remove vegetation and so offers high extraction rates.  相似文献   

ASE3OO与快速索氏抽提仪处理沉积岩样品的地化参数对比     

魏彩云  王汇彤  赵丽娜  张水昌  程磊 《矿物岩石地球化学通报》2012,31(1):89-95

本文对加速溶剂萃取仪(ASE300)和快速索氏抽提仪提取的氯仿沥青“A”及由其分离出的饱和烃、芳烃、胶质和沥青质组分做了详细对比.结果表明:多数情况下ASE300抽提出的氯仿沥青“A”的量比快速索氏抽提仪抽提出的量略多,主要是胶质和沥青质量的增加;不同抽提装置得到的饱和烃和芳烃组分的色谱-质谱谱图高度一致,定量结果的相对偏差在5％以内.各组分的稳定碳同位素分析精度±0.5‰.所有的地化参数表明ASE300完全可以替代快速索氏抽提仪,从而降低消耗、提高分析效率.  相似文献   

雨生红球藻多糖的提取分离及理化性质研究     

冯以明  李广生  吴建东  王培培  赵峡  于广利 《海洋科学》2012,36(1):17-22

将雨生红球藻(Haematococcus pluvialis)经乙醇/乙酸乙酯(1:2,V/V)脱脂,通过冷水、热水和5%碳酸钠提取,得到3种粗多糖(HPC、HPH和HPA),通过Q-Sepharose FF阴离子交换柱进一步分级,从HPC中得到HPC1、HPC2和HPC3共3种多糖组分。运用高效液相色谱法(HPLC)、红外光谱(IR)等方法对其单糖组成、相对分子质量和基本结构特征进行分析比较。结果表明,各组分单糖组成复杂,主要含有半乳糖(Gal)、甘露糖(Man)、阿拉伯糖(Ara)、葡萄糖(Glc)、葡萄糖醛酸(GlcUA)、半乳糖醛酸(GalUA)、木糖(Xyl)、鼠李糖(Rha)、岩藻糖(Fuc)、葡萄糖胺(GlcN)和半乳糖胺(GalN),其中,Gal含量最高,大于20%。多糖HPC1、HPC2和HPC3的相对峰位分子质量分别为502.6,373.2,577.5和300.5 ku。  相似文献   

萃取结晶法回收碳酸钠实验研究          下载免费PDF全文

樊光友  刘有智  祁贵生  张秀东  尚海茹 《盐湖研究》2009,17(3):44-47

研究了萃取结晶回收无机盐的过程,提出了萃取结晶回收盐的优势,并以水-碳酸钠-正丁醇体系为研究对象,分别考察了加料方式、正丁醇与碳酸钠溶液的溶剂比、温度、搅拌速率等因素对碳酸钠收率的影响。结果表明采用反加法、较大的溶剂比和搅拌速率有利于提高碳酸钠的收率,温度的影响不是特别明显。  相似文献   

含激电效应的CSAMT一维正演研究   总被引：3，自引：2，他引：1       下载免费PDF全文

岳安平  底青云  王妙月  石昆法 《地球物理学报》2009,52(7):1937-1946

地电体对频率域电磁波激发源的响应为电磁感应和激电效应的综合响应.传统CSAMT法进行数据正反演时认为大地介质电阻率是与频率无关的实数,而实际上因为激电效应,地下可极化体的电阻率是一个与频率相关的复数.为推进二者总体响应研究,并扩展激电法的应用范围,同时提高电磁法勘探的精度,本文基于Dias模型,以复电阻率代替不考虑地电体极化效应的直流电阻率,对CSAMT场源一维层状模型进行了正演模拟,为提取CSAMT信号中所含激电信息提供理论基础.结果表明,考虑激电参数后,视电阻率及相位响应曲线出现明显异常（包括远场、过渡场、近场）;极化前后振幅比值异常峰值、相位差值异常峰值可直观体现激电异常;异常峰值与极化层层厚、埋深以及电阻率变化有连续的对应关系.认为从频率域电磁法信号中提取激电信息有乐观的前景.  相似文献   

可变点约束叠前流体因子直接提取方法   总被引：1，自引：1，他引：0       下载免费PDF全文

杨培杰  王长江  毕俊凤  刘书会 《地球物理学报》2015,58(6):2188-2200

以Gassmann流体因子(Gassmann Fluid Item,GFI)为目标,提出了一种流体因子直接提取的新方法.首先,以贝叶斯反演框架为基础,将似然函数、先验信息以及Gassmann流体因子近似方程相结合,得到初始的目标函数;其次,进一步在初始目标函数中加入可变数量的点约束信息,并得到最终的目标函数;最后,通过求解该目标函数,就直接提取出了Gassmann流体因子.该方法的主要特点是不需要初始模型的参与,而是通过一个约束模型来控制提取结果的稳定性和准确性,并且可以从约束模型中选定不同数量的约束点进行约束,称为可变点约束.给出并讨论了三种常用的不同点约束模式和原则,并用模型说明了它们不同的约束效果.模型验证和实际应用结果皆以表明,该方法即使在叠前数据信噪比很低的情况下也能较好地提取出Gassmann流体因子,流体因子提取结果客观性高、稳定性好,并且能够与已知的流体解释结果很好地匹配,益于进一步推广应用.  相似文献   

溶剂萃取法提硼研究概述   总被引：3，自引：1，他引：2       下载免费PDF全文

高成花  邓小川  张琨 《盐湖研究》2010,18(1):49-52

溶剂萃取法作为一种有效的溶液提硼方法之一,对于硼资源的开发利用、环境保护以及其它化学工业的发展具有重要意义。从萃取剂、萃取工艺和萃取设备3个方面讨论溶剂萃取法提硼的研究进展,并对今后溶液提硼的发展方向进行展望。  相似文献   

Quantifying geological structures of the Nigde province in central Anatolia,Turkey using SRTM DEM data   总被引：1，自引：0，他引：1  

A. C. Demirkesen 《Environmental Geology》2009,56(5):865-875

A digital terrain model and a 3D fly-through model of the Nigde province in central Anatolia, Turkey were generated and quantitatively analyzed employing the shuttle radar topographic mission (SRTM) digital elevation model (DEM). Besides, stream drainage patterns, lineaments and structural–geological features were extracted and analyzed. In the process of analyzing and interpreting the DEM for landforms, criteria such as color and color tones (attributes of heights), topography (shaded DEM and 3D fly-through model) and stream drainage patterns were employed to acquire geo-information about the land, such as hydrologic, geomorphologic, topographic and tectonic structures. In this study, the SRTM DEM data of the study region were experimentally used for both DEM classification and quantitative analysis of the digital terrain model. The results of the DEM classification are: (1) low plain including the plains of Bor and Altunhisar (20.7%); (2) high plain including the Misli (Konakli) plain (28.8%); (3) plateau plain including the Melendiz (Ciftlik) plateau plain (1.0%); (4) mountain including the Nigde massif (33.3%); and (5) high mountain (16.2%). High mountain areas include a caldera complex of Mt Melendiz, Mt Hasan and Mt Pozanti apart from the Ala mountains called Aladaglar and the Bolkar mountains called Bolkarlar in the study region (7,312 km²). Analysis of both the stream drainage patterns and the lineaments revealed that the Nigde province has a valley zone called Karasu valley zone (KVZ) or Nigde valley zone (NVZ), where settlements and agricultural plains, particularly the Bor plain in addition to settlements of the Bor town and the central city of Nigde have the most flooding risk when a heavy raining occurs. The study revealed that the NVZ diagonally divides the study region roughly into two equal parts, heading from northeast to southwest. According to the map created in this study, the right side of the NVZ has more mountainous area, where the Aladaglar is a wildlife national park consisting of many species of fauna and flora whereas the left side of the NVZ has more agricultural plain, with exception of a caldera complex of Mt Melendiz and volcanic Mt Hasan. The south of the study region includes the Bolkarlar. In addition, the Ecemis fault zone (EFZ) lying along the Ecemis rivulet, running from north to south at the west side of the Aladaglar, forms the most important and sensitive location in the region in terms of the tectonics.  相似文献   

包裹体岩片卸洗新方法—索氏抽提法     

王朴  郝运轻  谢忠怀  甄贞  李博 《岩矿测试》2009,28(1):29-31

有机溶剂在恒温常压下封闭系统内,以浸泡淋洗的原理,建立了包裹体岩片卸洗新方法——索氏抽提法,克服了以往卸洗方法手工操作不便、难洗干净、易破碎、不能大批量处理等缺点。方法具有卸洗效率高、省心省力、操作方便、环保等优点,大大地提高了包裹体岩片卸洗的质量和效率。  相似文献   

Simplification of a Sequential Extraction Scheme To Determine the Mobilisable Heavy Metal Pool in Soils     

Tim Koeckritz  Jorg Thming  Christine Gleyzes  Knut E. degrd 《洁净——土壤、空气、水》2001,29(4):197-205

This investigation had the purpose of evaluating the reliability of a sequential extraction procedure according to Zeien and Brümmer (1989) which is performed routinely to analyse the distribution of heavy metals to different soil phases. Reliability was tested by two hypotheses. According to the first hypothesis an error propagation increased during a morefold extraction of heavy metals from a single soil sample to such an extend that it does not allow a statistical comparison of different analyses. This assumption was confirmed in an interlaboratory study of five participants applying the sequential extraction scheme on two different soils. The heavy metal amounts extracted by the different partners were of the same magnitude, but from the results no statistical correspondence at the 95% confidence level could be observed. The second hypothesis stated that also weak extraction agents were able to release metals from the more immobile soil fractions, especially if the amount of easily soluble metals was comparatively small. To answer this question the sequential extraction was modified by carrying out selected weak extraction steps several times. As expected the intensified extraction conditions caused a decrease of the element content within the more resistant phases. However, the additional release in the first four extraction steps of Pb, Mn, Fe, and Zn was only in the range of 5 to 10%. Furthermore, it was observed that a single EDTA extraction (step four within the sequential extraction scheme) was capable to extract the same amount of metals as the first four extraction steps of the original scheme at a variation of about 15%. From these results it was concluded that the EDTA step alone already represents a reliable pool of mobilisable metals. Thus it can be maintained that such a simple single EDTA extraction can be used to assess the environmental risk from heavy metal contaminated soils or to predict the potential heavy metal release of soil remediation processes.  相似文献