基于激光扫描和无人机倾斜摄影的露天采场安全监测应用

为解决露天采场安全监测中观测困难、效率低下等问题,结合引用三维激光扫描和无人机倾斜摄影等三维测量技术开展露天采场安全监测融合应用研究。通过应用研究表明:2类技术结合应用可实现露天采场生产环境信息完整三维数据采集;通过统一控制点坐标系和基于点云特征点的迭代最临近点配准算法（ICP）可有效融合2类点云数据,能构建高时效、高精度、高分辨率的采场三维点云模型;融合的三维模型能直观再现采场生产环境,多尺度精准监测安全隐患问题,有效辅助采场生产安全规划;该技术方案弥补了人工安全监测缺陷,提高了安全监测效率,可适用于矿山尾矿库、水电大坝等其他危险源安全监测应用。     

基于无人机遥感的岛状盐沼潮沟与植被发育特征研究

潮沟和植被是盐沼湿地系统的重要组成部分,探究二者在发育过程中相互作用形成的不同形态特征,有助于理解盐沼湿地生态系统的稳定性机制。本研究选取辽河口门头岗岛状盐沼,基于厘米级无人机遥感影像并结合GF-2卫星高分辨率遥感影像,采用地理信息系统（GIS）技术,获取了滩面75条潮沟系统和高精度的地形高程数据以及盐沼植被分布情况。通过对潮沟系统形态特征参数与植被覆盖度（Fractional Vegetation Coverage,FVC）的计算和系统性分析,得到了潮沟等级发育率与发育时间,以及潮沟曲率、密度与植被覆盖度间的相对关系,并发现了基于Gravelius分级法得到的1、2级潮沟夹角近似呈正态分布以及翅碱蓬在潮沟边缘的多种分布模式。这些发现揭示了潮沟与植被在不同发育阶段的形态特征,可为辽河口盐沼湿地在潮沟构建等方面的保护和修复工作提供理论参考。     

High-Resolution Vegetation Data for Mangrove Research as Obtained From Aerial Photography

In this methodological study, the applicability of aerial photographs for monitoring mangrove vegetation dynamics at high resolution was investigated. Vegetation maps of three mangrove forests in Sri Lanka (Galle, Rekawa and Pambala) were produced based on visual analysis of aerial photographs. The visual analysis was aided by applying an interpretation key constructed during a first fieldwork mission. Image attributes used for the identification of individual trees included: gray values, texture, form and size of the crowns and the presence or absence of a shaded side. For the identification of species assemblages, the vegetation structure (i.e. the distribution of individual trees) appeared to be an important attribute. The accuracy and reliability of the vegetation maps were investigated during a second fieldwork mission. The aerial photographs proved to be very useful for the production of genus-based vegetation maps. The error analysis showed that density estimations (quantitative identification) based on aerial photography was not sufficiently accurate for the objectives of the study, but that the overall identification of vegetation assemblages (qualitative identification) coincided most satisfactory with the ground-truth data. In addition to the applicability of aerial photography in monitoring mangroves, the importance of aerial photography in the management of the mangrove ecosystem is clearly highlighted.     

Evaluating post-Katrina recovery in Mississippi using repeat photography

Hurricane Katrina of August 2005 had extensive consequences for the state of Mississippi in the United States. Widespread infrastructure and property damage, massive social dislocation, and ecological loss remain among the many challenges faced by communities as they work towards 'normalcy'. This study employs repeat photography to understand differential recovery from Hurricane Katrina in Mississippi. Revealing change with conventional landscape photography, a process known as repeat photography, is common in the natural sciences. Simply stated, repeat photography is the practice of re-photographing the same scene as it appears in an earlier photograph. Photographs were taken at 131 sites every six months over a three-year period. Each photograph was assigned a recovery score and a spatially interpolated recovery surface was generated for each time period. The mapped and graphed results show disparities in the progression of recovery: some communities quickly entered the rebuilding process whereas others have lagged far behind.     

航空遥感地震灾害信息的快速提取

航空遥感地震灾害信息的快速提取是地震灾害损失快速评估的关键技术。遥感与地理信息系统的结合应用使得震害调查快速而又正确。本文重点论述了震害地类的特性与建立解译模型的原则、方法与不同种类信息源所采用的二套技术方案,并比较分析了二套技术方案各自的优势,探讨地震灾害信息快速提取的技术方法。     

“空地一体化”环境应急监测与管理系统设计

在总结我国环境应急管理体系建设现状的基础上,提出了"空地一体化"的环境应急监测与管理体系的框架和功能设计,介绍了引入无人机监测系统对环境应急体系的功能改进。最后从无人机机载传感器、"空地一体化"数据分析处理和通讯保障3个维度对关键技术的选择问题进行了探讨,分析了其现状、技术难点与发展趋势,以期为现代化的环境应急体系建设提供有益的参考。     

航空绿化遥感中的遮蔽校正计算

对航空绿化遥感调查中存在的绿化信息定量提取精度不足的缺陷,在分析航空遥感成像特点基础上,探讨了遮蔽现象对城市绿化信息提取精度的影响,进而推导出航空遥感遮蔽校正的计算公式,在实例研究的过程中,提出了3种遮蔽校正方法,并对其的计算结果进行了对比,分析了各自的适用条件。     

Precision Measurements from Very-Large Scale Aerial Digital Imagery

Managers need measurements and resource managers need the length/width of a variety of items including that of animals, logs, streams, plant canopies, man-made objects, riparian habitat, vegetation patches and other things important in resource monitoring and land inspection. These types of measurements can now be easily and accurately obtained from very large scale aerial (VLSA) imagery having spatial resolutions as fine as 1 millimeter per pixel by using the three new software programs described here. VLSA images have small fields of view and are used for intermittent sampling across extensive landscapes. Pixel-coverage among images is influenced by small changes in airplane altitude above ground level (AGL) and orientation relative to the ground, as well as by changes in topography. These factors affect the object-to-camera distance used for image-resolution calculations. ‘ImageMeasurement’ offers a user-friendly interface for accounting for pixel-coverage variation among images by utilizing a database. ‘LaserLOG’ records and displays airplane altitude AGL measured from a high frequency laser rangefinder, and displays the vertical velocity. ‘Merge’ sorts through large amounts of data generated by LaserLOG and matches precise airplane altitudes with camera trigger times for input to the ImageMeasurement database. We discuss application of these tools, including error estimates. We found measurements from aerial images (collection resolution: 5–26 mm/pixel as projected on the ground) using ImageMeasurement, LaserLOG, and Merge, were accurate to centimeters with an error less than 10%. We recommend these software packages as a means for expanding the utility of aerial image data.     

面向交通事故现场三维实景建模的无人机航拍参数

在交通事故现场三维实景建模的图像采集过程中,针对无人机（UAV）航拍参数主要依靠人工经验设置,导致模型测量误差大、精度低的问题,提出一种无人机航拍关键参数自动计算方法。首先,确认单镜头无人机环绕事故现场航拍的关键参数为航拍高度、云台角度和拍摄间隔角,并分析其与成像范围、成像精度以及重叠度的数值关系;然后,构建无人机航拍关键参数计算模型,以给定事故现场场景、无人机技术参数、图像长宽比以及重叠度要求为输入,在事故现场处于有效成像范围且无成像盲区的前提下,以提高图像利用率保障模型精度和呈现效果为目标,自动计算得到航拍参数;最后,结合实例,应用该方法计算无人机航拍参数完成事故现场的图像采集,经测算,构建的事故现场三维实景模型的平均测量误差为1.72%,测量精度为3.54 cm,相较于人工经验法平均误差降低47.56%,精度提高48.40%。研究表明：该方法能实现交通事故现场三维实景建模的航拍参数自动计算,构建厘米级误差的三维实景模型,可提升无人机航拍的参数化和自动化水平。     

三维倾斜摄影技术在尾矿库风险防控上的运用

为提高尾矿库信息化安全管理水平,保障尾矿库安全平稳运行.采用无人机倾斜摄影技术对尾矿库及下游区域进行影像数据采集,创建尾矿库三维图像,并将尾矿库空间三维模型关键数据与企业设计数据进行对比分析,对尾矿库汛期防洪能力进行预测分析.结果表明:该技术能够及时发现尾矿库运行期间存在的隐患,防范化解尾矿库安全风险,提高预测尾矿库汛...