4种无人机遥感影像快速拼接方法的试验分析

无人机遥感技术凭借其操作方便、灵活性高、分辨率高、投入成本低、现势性好等优势,已经成为获取遥感数据的重要方法之一。但不可否认的是,无人机遥感技术也存在影像量大、像幅小、无规律、拼接难的缺陷。因此,针对无人机遥感影像的拼接处理问题,本文通过试验对比了几种无人机遥感影像拼接方法,并对这几种拼接方法的精度以及应用范围进行了分析。     

Progress in the study on the formation of the summertime subtropical anticyclone

The studies in China on the formation of the summertime subtropical anticyclone on the climate timescale are reviewed. New insights in resent studies are introduced. It is stressed that either in the free atmosphere or in the planetary boundary, the descending arm of the Hadley cell cannot be considered as a mechanism for the formation of the subtropical anticyclone. Then the theories of thermal adaptation of the atmosphere to external thermal forcing and the potential vorticity forcing are developed to understand the formation of the subtropical anticyclone in the three-dimensional domain. Numerical experiments are designed to verify these theories. Results show that in the boreal summer, the formation of the strong South Asian High in the upper troposphere and the subtropical anticyclone over the western Pacific in the middle and lower troposphere is, to a great extent, due to the convective latent heating associated with the Asian monsoon, but affected by orography and the surface sensible heating over the continents.On the other hand, the formation of the subtropical anticyclone at the surface over the northern Pacific and in the upper troposphere over North America is mainly due to the strong surface sensible heating over North America, but affected by radiation cooling over the eastern North Pacific. Moreover, in the real atmosphere such individual thermal forcing is well organized. By considering the different diabatic heating in synthesis, a quadruple heating pattern is found over each subtropical continent and its adjacent oceans in summer. A distinct circulation pattern accompanies this heating pattern. The global summer subtropical heating and circulation may be viewed as “mosaics” of such quadruplet heating and circulationpatterns respectively. At last, some important issues for further research in understanding and predicting the variations of the subtropical anticyclone are raised.     

影响山东的台风温比亚（1818）中尺度云团“列车效应”特征分析

基于多普勒天气雷达、区域气象观测站、常规观测和NCEP再分析数据等,利用三维雷达拼图技术对2018年第18号台风“温比亚”造成的山东暴雨中尺度特征进行分析。研究表明：台风“温比亚”造成的山东暴雨,不同阶段雨强特征有较大差异,长时间强降雨是造成灾害性暴雨的主要因素;此次台风暴雨雨团具有很强的移动特征,是否形成“列车效应”是造成灾害性暴雨的重要因素;雷达三维拼图数据可以清晰识别和分析暴雨过程中尺度雨团的移动、合并和发展规律,这些对准确监测预报暴雨的发生至关重要。     

景观格局的数量研究方法

依据景观局数量方法的研究进展,从单个斑块特征分析、单一景观要素的格局分析及景观镶嵌体特征分析等三个方面介绍了数量分析方法,并介绍最常用的和近年来发展的新方法。     

TM图像的大地校正及其镶嵌方法研究

大地校正和数字图像镶嵌是应用遥感图像进行资源环境监测工作的基础,其精度的高低将对后续工作产生直接影响。基于经过系统校正的TM图像内部几何精度高的前提,本文提出一种快速实用的大地校正及图像镶嵌方法,该方法避免了传统方法在应用控制点建立拟合方程时耗时长的缺点,保证了TM镶嵌图像的几何精度.     

基于二进小波变换的遥感影像镶嵌方法

提出了一种新的影像镶嵌方法。通过与经典的直方图色调匹配方法实验结果比较,证明该方法克服了相邻影像中局部灰度差异大的问题,保证了接缝邻域处的图像清晰度和光滑度两个方面的要求。     

数字摄影测量工作站(JX4C DWP)制作无缝正射影像的经验与技巧

在数字正射影像数据应用工作中以及进行正射影像数据库的建库实际作业当中,制作无缝正射影像数据是非常重要的一环,笔者在实践中摸索并总结了一些制作无缝正射影像数据的作业方法和技巧,仅供同行参考。     

一种基于Mosaic Dataset的海量影像数据处理方法

高精度海量影像数据是天地图、数字城市等公共服务平台的基础数据源之一。巨大的数据量使得传统影像数据加工方法的效率大大降低,这也成为制约公共服务平台数据生产效率的瓶颈之一。本文基于ArcGIS10版本推出的Mosaic Dataset模型,实现了海量高精度影像数据的高效处理,从海量数据管理、数据预处理、投影变换、去黑边、填补空洞等方面,详细叙述了该模型在海量影像数据处理方面的应用。本研究期望为相关数据加工与生产提供借鉴。     

QUANTITATIVE ANALYSIS AND FRACTAL MODELING ON THE MOSAIC STRUCTURE OF LANDSCAPE IN THE CENTRAL AREA OF SHANGHAI METROPOLIS

The mosaic structure of landscape of the central area of Shanghai Metropolis is studied by quantitative methods of landscape ecology based on Remote Sensing (RS) and Geographic Information System (GIS) in this pa-per. Firstly, landscapes are classified into eight categories: residential quarter, industrial quarter, road, other urban landscape, farmland, village and small town, on-building area, river and other water bodies (such as lake, etc.). Sec-ondly, a GIS is designed and set up based on the remote sensing data and field investigation, and a digital map of landscape mosaic is made. Then the indexes of diversity, dominance, fragmentation and isolation, and fractal dimen-sion of each type of landscape in different periods are calculated by using spatial analysis method of GIS. With refer-ence to the calculated results, a series of relative issues are discussed.     

北京1号小卫星多光谱影像全国镶嵌技术与制图研究

北京1号小卫星在轨运行一年多成功接收了覆盖中国各个行政区域的多光谱影像数据,为全国数字镶嵌图的研究提供了丰富的数据资料.针对北京1号小卫星特点进行关键技术和方法研究,形成了北京1号小卫星多光谱影像全国范围数据获取任务测控优化模式,解决了北京1号小卫星多光谱数据预处理中去条带、波段自动配准、MTF复原处理等关键技术,系统地、全面地阐述了全国镶嵌图制作的技术流程和方法.