基于旋翼无人机的大气边界层环境气象垂直观测及订正方法的研究

基于旋翼无人机开展大气边界层观测可为气象要素和大气污染物垂直结构的研究提供具有高时空解析能力的新方法,有助于深入理解低层大气物理化学变化机制。本文详述了旋翼无人机在开展大气边界层环境气象垂直观测实验的应用及优势。基于自主研发的旋翼无人机环境气象观测平台,通过开展传感器在无人机上不同的搭载位置,以及旋翼无人机与探空气球、高塔的对比观测实验,明确了旋翼无人机对气象环境观测的影响及合理的搭载方式。研究进一步在湖北重污染天气条件下开展了0—1000 m的大气边界层垂直观测,并研发了基于旋翼无人机姿态数据的大气边界层气象要素及污染物垂直观测的订正方法。结果表明:实验获取了2—10 m垂直分辨率的高质量大气廓线数据,可精细捕捉大气边界层及其逆温层高度和污染物浓度等要素的垂直变化特征。本文旨在为无人机观测的科研应用提供一种技术可行且数据可靠的观测手段。     

全数字摄影测量方法在地理信息数据更新中的应用

社会的飞速发展对测绘工作提出了新的要求,数据的现势性、数据采集的快速性矛盾逐渐突出,传统的数据更新方法生产成本高,更新周期长,已不能满足社会高速发展的需要。探索一条快速、高效的数据更新方法迫在眉睫。该文全面介绍了利用全数字摄影测量方法对已有1：1万3D数字产品进行更新的方法和技巧,在很大程度上缩短了数据更新周期,降低了数据更新的成本,提高了工作效率。     

ERDAS在1：l万地形图调绘片纠正中的应用

本文介绍利用ERDAS的几何纠正功能对1：1万调绘片进行纠正的原理和方法。实验证明此种方法的纠正结果不仅可以保证较高精度而且与DLG数据叠加具有良好效果,可以作为底图进行数据编辑。     

Using horizontal and vertical building structure to constrain indirect sensor orientation

This paper presents a method to integrate linear horizontal, vertical and right-angled scene structures into the bundle adjustment of image sequences. An increasing number of airborne image acquisition systems is available and equipped with non-metric small- or medium-frame cameras and no or insufficiently accurate INS devices. In cases where the data is to be used for the production of geo-spatial data, where a certain accuracy and precision is required, an indirect sensor orientation, possibly including self-calibration, needs to be performed. The idea which led to the presented approach is to reduce the number of GCPs necessary for this task by applying the mentioned scene structures. The method directly uses the linear structures, visible at man-made objects as fictive observations within the adjustment, while self-calibration of intrinsic camera parameters and lens distortion is included as well.Experiments with two datasets demonstrate that, through this method, only limited GCP information is required to obtain satisfactory results. In fact, in one experiment using oblique images, several scene constraints were provided and only the datum was defined by ground control. The residuals at check points from this setup were similar to the traditional case where several well-distributed GCPs were available in the scene. In the second experiment the ability of this approach to support the bundle adjustment was shown for a UAV dataset. Although no GCP and camera calibration information was available, the visual inspection of adjusted object points and the residuals at horizontal structures confirmed the ability of the method to align an image block with the structure, as embodied in the defined scene constraints. Despite the convincing outcome of the experiments, it needs to be mentioned that some manual work is still involved in defining the constraints. In future work the issue of automation will be addressed.     

Spatio-temporal changes in land cover and aquatic macrophytes of the Danube floodplain lake

The aquatic vegetation of ?í?ov Lake in the Danube floodplain, which is listed in the Ramsar Convention, was investigated to address three main questions: (1) how have landscape composition and the structures of the lake and its buffer zone changed from the mid-20th century; (2) how have species richness and the abundance of the aquatic macrophyte assemblage in this lake ecosystem changed over the last 34 years; and (3) which landscape metrics can best explain these temporal changes for floating-leaved macrophytes? Two methodological approaches, remote sensing and botanical field surveys, were applied. Historical (1949, 1970, 1990) and contemporary (2006) aerial photographs were analysed to determine land cover. Landscape configuration and structure were analysed using eight landscape metrics selected in advance to measure spatio-temporal changes and the fragmentation of the lake ecosystem and its corresponding buffer zone. The species diversity, abundance and distribution of true aquatic macrophytes were surveyed eleven times in five survey stretches between 1973 and 2007.At the landscape level, a decrease in the area covered by floating-leaved macrophytes, as well as an increase in open water surface and fragmentation of the land cover classes in the lake ecosystem, were recorded from 1949 to 2006. Overall, 30 true aquatic macrophytes were found from 1973 to 2007. Species richness did not change considerably, but the abundance of aquatic species fluctuated over the years. Three groups of true aquatic vegetation, based on common structural characteristics, were found in 1973–1983, 1989–2002, and 2004–2007 over the last 34 years. The landscape metrics NP, PD, LPI, and SHDI, which all express patterns of landscape fragmentation mostly indicate temporal changes in floating-leaved macrophytes.     

南极测绘中小像幅航片的区域网平差

本文介绍了用日产 Bronika SQ- A1 2 0型非量测相机对东南极拉斯曼丘陵 1 :40 0 0 0摄影比例尺小像幅航片进行加密的情况。通过用武汉测绘科技大学研制的联合平差程序 Wu CAPS软件的带附加参数的光束法区域网平差获得了实地上平面± 2 .82 9m,高程± 4.973 m的加密精度。文中还分析了若干精度问题 ,所得结论对今后的进一步研究将有所裨益     

3D urban models: Recent developments in the digital modelling of urban environments in three-dimensions

This paper reports on recent developments in the visualisation of urban landscapes. There is a growing interest in the contstruction of 3D models of urban and built environment for which a host of digital mapping and rendering techniques are being developed. This paper extracts some of the cases that we came across during worldwide interviews carried out in March 2000. Building on this review, we identify the range of data and techniques adopted for the development of 3D contents and how they could contribute to geographical analysis and planning of urban environment. A particular focus is given on the effectiveness of GIS and its related methods for their capacity to accommodate the demands for visual representation of urban environment as well as the basis for analysis and simulation. This revised version was published online in July 2006 with corrections to the Cover Date.     

基于多种软件进行无人机数据空三加密处理方法的探讨

随着无人机在测绘行业的广泛利用与推广,快速便捷处理无人机数据成为研究热点.本文以无人机数据的空三加密处理为主,介绍了PhotoScan、INPHO、SVSUAV三种软件的无人机数据处理的流程及其优缺点,提出了利用各软件优点与数据兼容特点,结合不同软件平台进行无人机数据空三加密处理,提升了空三加密整体精度,并为后续的DL...     

无人机航测技术在海草床调查中的试点应用

通过无人机飞行参数、飞行高度、潮汐条件和调查范围等试验,采用无人机对东郊椰林近岸海域海草进行航拍,利用PIX4D软件处理得到了高分辨率海草分布影像图,利用ArcGIS软件对海草分布区进行了矢量化提取,选择有代表性的区块结合实地调查进行验证,得出了试验区的海草分布特征和海草种类。结果表明：海草分布在离岸300 m范围内的珊瑚礁砰上,呈斑块状、间隔式分布特征,在试验区中海草分布面积为2 449.6 m²,占比为24.5%。实地调查到海草种类有圆叶丝粉草(Cymodocea rotundata)、单脉二药草(Halodule uninervis)、海菖蒲(Enhalus acoroides)、泰来草(Thalassia hemprichii)和卵叶喜盐草(Halophila ovalis)等5种海草,泰来草为优势种,单脉二药草和卵叶喜盐草分布在潮间带有淤泥的低潮区;圆叶丝粉草分布在低潮带至潮下带的上部,海底堆积和冲刷区的交界处;泰来草在不同水深处均有分布,分布面积最大。     

倾斜摄影技术在丘陵山区大比例尺测图中的应用

针对丘陵山区大比例尺测图应用的需求,本文探讨了如何通过倾斜摄影的技术方法获取高精度的影像模型.首先通过分析航线布设方法、控制点布设采集要点、空三数据处理关键点等,获取满足丘陵山区大比例尺测图应用的数据模型,基于数据模型获取大比例尺地形图数据;然后通过与实地测量数据进行精度对比分析获取试验结果,结果表明倾斜摄影技术不但能...