高分辨率遥感影像制作方法创新

随着卫星遥感获取技术的发展,运用遥感技术获取的影像资源日益丰富,特别是高分辨率遥感影像被列入国家重大工程建设以来,其在制作正射影像、三维模型、对地观测系统等方面作用突出,能够真实地反映研究地区地表的各种地理信息特点。与此同时,高分辨率遥感影像能够在实时状态下获取地理信息,可满足未来信息化战争、非战争军事行动等对地理环境保障提出的新要求。本文结合工作实际,对高分辨率遥感影像制作方法,以及影像制作中方案的改进进行探讨,取得了事半功倍的效果。     

OESM辅助的高分辨率航空正射影像拼接线自动检测算法

针对常规拼接线检测算法在城市区域影像镶嵌时容易出现拼接线穿越建筑物从而破坏地物完整性的问题,提出了一种影像高程同步模型(OESM)辅助的拼接线自动检测算法。该算法首先通过对OESM模型规格化处理标识正射影像中的地物目标;然后在非地物目标区利用改进贪婪蛇算法检测拼接线。通过对建筑物密集分布的城市区域影像进行拼接线检测实验表明,该算法是一种理想的拼接线检测算法。     

资源三号影像的DOM制作对比分析

为了提高国产资源三号卫星影像数据制作DOM的效率,文章对比分析了PixelGrid与PixelFactory软件在DOM制作过程中各个环节的特点,主要从数据准备、提取控制点、影像配准、纠正融合、匀光调色、几何精度、操作环境等方面进行对比分析,总结添加基础数据方式、对提点结果所提供的处理方式、影像匀光调色方式、几何精度、操作环境等的特点,为相关研究提供参考。     

Sources and biodegradability of dissolved organic matter in two headwater peatland catchments at the Marcell Experimental Forest,northern Minnesota,USA

Where they are present in catchments, peatlands are a dominant source of dissolved organic matter (DOM) to surrounding waterways due, in part, to high production rates. Despite the preponderance of peatlands in northern latitudes and expected peatland vulnerability to climate change, little is known about peatland DOM degradation relative to a more comprehensive understanding of degradation when DOM is sourced from upland-dominated catchments. We compared DOM biodegradability of various sources of stream water in two catchments having peatlands (22%–33% of the area) surrounded by upland forests (70%–90% of the area, either deciduous or coniferous). We measured total organic carbon (TOC), and biodegradable dissolved organic carbon concentrations; bacterial respiration rates; streamflow; and upland runoff during and after snowmelt (March to June, 2009–2011). We also explored if DOM in upland runoff stimulated biodegradation of peatland-derived DOM (i.e., a priming effect), and if forest cover type affected DOM biodegradability. As expected, the peatlands were the largest sources of both water (72%–80%) and TOC (92%–96%) to the streams although more area in each catchment was in uplands (70%–90%). Several results were unexpected, yet revealing: (1) DOM from peatlands sometimes had the same biodegradability as DOM from uplands, (2) upland sources of DOM had negligible effects on biodegradability in the peatland and downstream, and (3) upland deciduous cover did not yield more degradable DOM than conifer cover. The most pronounced effect of upland runoff was dilution of downstream TOC concentrations when there was upland runoff. Overall, the effects of upland DOM may have been negligible due to the overriding effect of the large amount of biodegradable DOM that originated in bogs. This research highlights that peatland-sourced DOM has important effects on downstream DOM biodegradability even in catchments where upland area is substantially larger than peatland area.     

基于Pixelgrid的无人机数据处理

工程施工前的设计阶段必须对土石方量进行预算,它直接关系到工程的费用概算及方案选优。在现实中的一些工程项目中,因土方量计算的精确性而产生的纠纷也是经常遇到的。如何利用测量单位现场测出的地形数据或原有的数字地形数据快速准确地计算出土方量就成了人们日益关心的问题,比较经常使用的几种计算土方量的方法有：方格网法、断面法、平均高程法和DTM法（不规则三角网法）等。     

基于激光点云的3维可视化方法

介绍了利用3维激光点云与数字影像,生成云冈石窟正射影像的原理与方法.采用激光扫描与数码相机同步获取石窟、石佛的3维点云与数字影像,建立点云与数字影像映射关系模型,将影像的纹理信息赋予3维点云模型,实现点云模型真彩色3维可视化,并在此基础上生成正射影像图.研究成果对于历史遗迹、文物保护与修复具有重要意义.     

垃圾渗滤液水溶性有机物对污染土壤中重金属Pb迁移性的影响

采用土柱淋滤试验研究了不同填埋年限的垃圾渗滤液DOM在土壤中垂直迁移及其对土壤重金属Pb淋滤溶出的影响。结果表明,不同填埋年限(0.4~5.12 a)的垃圾渗滤液DOM在土壤中垂直向下的迁移速率存在差异,填埋时间短的垃圾渗滤液DOM在土壤中迁移性较强。与对照相比(不加渗滤液DOM),垃圾渗滤液处理对红壤中土壤重金属Pb的累积解吸率高74.25%;在潮土上高-38.79%,且垃圾填埋年限中期的渗滤液DOM对土壤重金属的溶出影响更显著,说明垃圾渗滤液DOM进入土壤环境对重金属的迁移有促进作用。