机载激光雷达对青岛及周边海域的气溶胶探测   总被引：12，自引：1，他引：11       下载免费PDF全文

毛敏娟  张寅超  方海涛  戚福弟  邵石生  胡欢陵  周军 《地球物理学报》2007,50(2):370-376

工作波长为532 nm的机载大气环境探测激光雷达AEDAL（Atmospheric Environment Detecting Airborne Lidar）装载在CMS_3807飞机上,于2005年11月7～11日期间在青岛地区及周边海域上空进行了飞行探测.此次实验的目的有两个：验证我国用于大气环境探测的激光雷达技术已经具备从地基向空基乃至天基发展的条件;获得青岛地区及周边海域边界层结构及大气气溶胶时空分布变化的特点.激光雷达的高时空分辨率为获取飞行路径上的边界层结构及气溶胶时空分布提供了可能.为了研究下垫面对边界层及气溶胶时空分布的影响,预定的飞行路径上包含了丰富的地形变化,有城市、丘陵、海区等.通过给出11月8日及11日的探测结果,不仅得到了不同地区边界层结构及气溶胶的时空分布特点,还可以看到冷锋、地形、地面气象场等因素对它们的影响.  相似文献   

无人机倾斜摄影与LiDAR融合监测技术     

侯方国  刘欣  任秀波 《测绘通报》2022,(11):128-131

本文以成都市环城生态区生态修复项目为依托,利用飞马D200无人机实现了倾斜摄影和LiDAR技术的融合监测,通过三维模型制作、大比例尺地形图生产、点云处理、方格网计算、精度评定等步骤,验证了倾斜摄影和机载LiDAR协同监测方式可以满足1∶500地形图和方格网测量的精度,对后期无人机测绘实际生产具有指导意义。  相似文献   

基于纹理特征的围填海SAR图像分水岭分割方法          下载免费PDF全文

王衍  许小贝  洪海凌 《海洋学研究》2018,36(2):44-49

本文提出了一种基于纹理特征的围填海SAR图像分水岭分割方法,首先对机载MiniSAR图像进行灰度共生矩阵纹理滤波,获得纹理特征图像,再对纹理特征图像进行分水岭算法分割,将获得的形态学重建图像进行门限阈值分割,得到最后的二值化分割结果。该方法一方面通过调整灰度共生矩阵纹理滤波的窗口大小,抑制了斑点噪声的影响;另一方面,利用分水岭算法对边缘模糊杂乱图像的优势,提高了围填海信息提取的准确性。实验结果表明,本方法对高分辨率SAR图像围填海监测图像的分割效果良好。  相似文献   

机载LiDAR地形特征信息快速提取     

刘智敏  杨安秀  宿殿鹏  刘盼 《大地测量与地球动力学》2018,38(11):1186-1190

为更有效地获取地形特征信息,提出一种机载LiDAR地形特征信息快速提取算法。首先,通过构建二次曲面拟合模型,建立实测LiDAR地形数据与拟合曲面的几何规则;然后,采用LM算法迭代参数寻优,获得最优化结果下的地形拟合参数,计算拟合时间及拟合精度;最后,以地形拟合模型为基础,进行地形特征信息的快速提取。通过机载LiDAR实测数据验证,当最优搜索半径为2 m时,地形曲面的拟合时间仅为0.02 s,RMSE仅为5.09 cm。该算法保证了地形特征信息提取效率和精度,能够有效满足机载LiDAR科学研究和工程应用的技术需求。  相似文献   

捷联式航空重力扰动矢量解算及误差补偿     

郭栋  孙中苗  吴富梅  张琪 《大地测量与地球动力学》2018,38(12):1295-1301

介绍捷联式航空重力矢量测量的基本原理,利用波数相关滤波（WCF）、比力线性校正的方法对重力扰动的水平和垂向分量进行误差补偿,评定内符合精度。对国产捷联式航空重力矢量仪的某次试验数据进行处理,以验证和评估航空重力矢量仪的性能。结果表明,在半波长分辨率为7.5 km时,6条重复测线的重力扰动水平分量经波数相关滤波处理后,东、北向分量的平均内符合精度分别从9.77 mGal、9.18 mGal提高到5.95 mGal、3.83 mGal;对比力的垂向分量线性校正后,将解算的重力扰动垂向分量再用WCF方法处理,其平均内符合精度从1.27 mGal提高到0.59 mGal。  相似文献   

Capabilities of the bathymetric Hawk Eye LiDAR for coastal habitat mapping: A case study within a Basque estuary   总被引：1，自引：0，他引：1  

Guillem Chust  Maitane Grande  Ibon Galparsoro  Adolfo Uriarte  Ángel Borja 《Estuarine, Coastal and Shelf Science》2010

The bathymetric LiDAR system is an airborne laser that detects sea bottom at high vertical and horizontal resolutions in shallow coastal waters. This study assesses the capabilities of the airborne bathymetric LiDAR sensor (Hawk Eye system) for coastal habitat mapping in the Oka estuary (within the Biosphere Reserve of Urdaibai, SE Bay of Biscay, northern Spain), where water conditions are moderately turbid. Three specific objectives were addressed: 1) to assess the data quality of the Hawk Eye LiDAR, both for terrestrial and subtidal zones, in terms of height measurement density, coverage, and vertical accuracy; 2) to compare bathymetric LiDAR with a ship-borne multibeam echosounder (MBES) for different bottom types and depth ranges; and 3) to test the discrimination potential of LiDAR height and reflectance information, together with multi-spectral imagery (three visible and near infrared bands), for the classification of 22 salt marsh and rocky shore habitats, covering supralittoral, intertidal and subtidal zones. The bathymetric LiDAR Hawk Eye data enabled the generation of a digital elevation model (DEM) of the Oka estuary, at 2 m of horizontal spatial resolution in the terrestrial zone (with a vertical accuracy of 0.15 m) and at 4 m within the subtidal, extending a water depth of 21 m. Data gaps occurred in 14.4% of the area surveyed with the LiDAR (13.69 km²). Comparison of the LiDAR system and the MBES showed no significant mean difference in depth. However, the Root Mean Square error of the former was high (0.84 m), especially concentrated upon rocky (0.55–1.77 m) rather than in sediment bottoms (0.38–0.62 m). The potential of LiDAR topographic variables and reflectance alone for discriminating 15 intertidal and submerged habitats was low (with overall classification accuracy between 52.4 and 65.4%). In particular, reflectance retrieved for this case study has been found to be not particularly useful for classification purposes. The combination of the LiDAR-based DEM and derived topographical features with the near infrared and visible bands has permitted the mapping of 22 supralittoral, intertidal and subtidal habitats of the Oka estuary, with high overall classification accuracies of between 84.5% and 92.1%, using the maximum likelihood algorithm. The airborne bathymetric Hawk Eye LiDAR, although somewhat limited by water turbidity and wave breaking, provides unique height information obscured from topographic LiDAR and acoustic systems, together with an improvement of the habitat mapping reliability in the complex and dynamic coastal fringe.  相似文献   

Remote sensing of water depths in shallow waters via artificial neural networks     

Özçelik Ceyhun  Arısoy Yalçın 《Estuarine, Coastal and Shelf Science》2010

Determination of the water depths in coastal zones is a common requirement for the majority of coastal engineering and coastal science applications. However, production of high quality bathymetric maps requires expensive field survey, high technology equipment and expert personnel. Remotely sensed images can be conveniently used to reduce the cost and labor needed for bathymetric measurements and to overcome the difficulties in spatial and temporal depth provision. An Artificial Neural Network (ANN) methodology is introduced in this study to derive bathymetric maps in shallow waters via remote sensing images and sample depth measurements. This methodology provides fast and practical solution for depth estimation in shallow waters, coupling temporal and spatial capabilities of remote sensing imagery with modeling flexibility of ANN. Its main advantage in practice is that it enables to directly use image reflectance values in depth estimations, without refining depth-caused scatterings from other environmental factors (e.g. bottom material and vegetation). Its function-free structure allows evaluating nonlinear relationships between multi-band images and in-situ depth measurements, therefore leads more reliable depth estimations than classical regressive approaches. The west coast of the Foca, Izmir/Turkey was used as a test bed. Aster first three band images and Quickbird pan-sharpened images were used to derive ANN based bathymetric maps of this study area. In-situ depth measurements were supplied from the General Command of Mapping, Turkey (HGK). Two models were set, one for Aster and one for Quickbird image inputs. Bathymetric maps relying solely on in-situ depth measurements were used to evaluate resultant derived bathymetric maps. The efficiency of the methodology was discussed at the end of the paper. It is concluded that the proposed methodology could decrease spatial and repetitive depth measurement requirements in bathymetric mapping especially for preliminary engineering application.  相似文献   

自动表面船用于岛礁水深测绘   总被引：1，自引：0，他引：1  

金久才  张杰  王岩峰  官晟  程凯  刘善伟 《海洋技术学报》2010,29(2)

岛礁具有重要的地位,然而对其附近水深的调查手段却不充分。比较了几种水深测绘手段的优缺点,设计了一种小型自动表面船用于岛礁水深测绘。该表面船底部安装声学测深仪,具备自动定位、导航与运动功能;其尾部安装两个电动推进器提供动力,通过独立控制两个推进器的转速,可实现船体的前进、后退和转向;利用无线电与岸基单元进行数据通讯。根据不同水深测绘条件,该船可以用三种控制方式进行水深测量:直接控制、间接控制和自主控制。测量数据实时传输到岸基单元,并自动存储于船载存储单元。初步试验结果表明,设计的自动表面船测量系统具有可行性。  相似文献   

基于机载LiDAR和倾斜影像的城市三维建模方法     

王旭科  闫世伟  李艳芳  李龙 《北京测绘》2021,35(1):51-55

"数字孪生"城市建设是近两年新兴的一条建设智慧城市的技术路径,它是构建一个与现实物理城市匹配对应的数字城市,实现城市要素数字化,其核心数据之一是高度仿真的城市三维模型.本文在研究机载LiDAR点云、倾斜摄影和三维可视化等技术之后,探讨了利用机载LiDAR和倾斜影像进行互补融合,构建城市三维模型的方法,并详细描述了三维建...  相似文献   

Fractal reconstruction of sea-floor topography     

Jean-Claude Mareschal 《Pure and Applied Geophysics》1989,131(1-2):197-210

Sea-floor bathymetric profiles exhibit features at many different scales of length; this suggests that they could be described as fractals. An algorithm interpolating a fractal line between points has been used to reconstruct bathymetric profiles from a few data points. In general, this fractal line has the same Fourier amplitude spectrum as real bathymetry, and, if the parameters of the interpolation are suitably chosen, it has a very similar appearance. The success of this fractal reconstruction algorithm for the sea-floor raises the possibility that it could be used to extrapolate, from data collected at one scale, the properties of the sea-floor at finer scales, and that similar techniques could be used to interpolate a surface between bathymetric profiles. The fractal character is a sign that the processes that shape the sea-floor are scale invariant and suggests that the renormalization group technique could be used to model these processes.  相似文献