THE THEORY AND APPLICATION OF THE STRUCTURE LIGHT ENGINEERING SURVEYING BASED ON A LASER THEODOLITE WITH THREE FREEDOMS OF ROTATION

1　ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｏｕｒｃｏｕｎｔｒｙ ,ｔｈｅｓｕｒｖｅｙｉｎｇｗｏｒｋｏｎｉｎｄｕｓｔｒｉａｌｏｂｊｅｃｔｓｈａｖｅ ｇｒａｄｕａｌｌｙｉｎｃｒｅａｓｅｄ .Ｔｈｏｓｅｉｎｄｕｓｔｒｉａｌｏｂｊｅｃｔｓｉｎｃｌｕｄｅｒａｉｌｗａｙａｎｄｈｉｇｈｗａｙｔｕｎｎｅｌｓ,ｖａｒｉ ｏｕｓｏｉｌａｎｄｇａｓｃａｎｓ ,ｖａｒｉｏｕｓａｉｒｃｒａｆｔ,ｓｈｅｌｌｏｆｃａｒｓ,ｌａｒｇｅｍｉｌｉｔａｒｙａｎｔｅｎｎａｕｓｅｄｆｏｒｓｃｏｕｔｉｎｇｓｔｅａｌｔｈｐｌａｎｅ ,ｓｈｉｐ ,ｉｎｔｅｒｎａｌｓｔ…     

遥感GPP模型在高寒草甸的应用比较

随着遥感数据时空分辨率的提高,大范围实时监测总初级生产力GPP(Gross Primary Productivity)的变化成为可能。本研究收集了黑河流域阿柔冻融观测站的气象观测资料和MODIS数据,驱动VPM、TG、VI和EC-LUE4个模型估算了该站点的GPP,并应用涡动相关观测的GPP验证了模拟结果,并比较了这4个模型的模拟精度。结果表明:阿柔站2009年的涡动相关观测的GPP、NEE(Net Ecosystem Exchange)和ER(Ecosystem Respiration)分别为:804.2gC/m2/yr、129.6gC/m2/yr和673.6gC/m2/yr。该站点光合作用固定的碳有83.8%通过生态系统的呼吸作用释放到大气中。基于遥感的GPP模型能够很好地模拟高寒草甸的GPP,全年的判定系数在0.94以上,生长季的判定系数大于0.84。     

基于空间认知的三维地图光影模型

针对现有三维地图在光照与阴影表达上存在的表现手法单一、调节功能欠缺、认知作用有限等诸多不足,从色彩学的角度探讨光照与阴影的颜色随经纬度和时间变化而变化的规律,充分考虑人们的空间认知习惯,建立一种简单可行的三维地图光影模型,可以非常方便、逼真地模拟任何地方的光照与阴影时空变化过程及规律,为人们在使用已有三维建模软件或利用组件式技术开发三维地图可视化软件时提供依据,以增强三维地图的视觉表达效果。     

基于线结构光视觉方法的绝缘子防污参数测量

提出了基于结构光视觉量测原理的绝缘子防污参数测量方法,采用非接触的测量方式高效地获取绝缘子带有结构光条影像,充分利用摄影测量、视觉量测技术和目标旋转体的几何结构特性,实现了变电站输变电设备带电工作状态下的绝缘子几何模型重建和防污参数量测。试验证明,该方法的自动化程度和精度可以满足绝缘子防污参数工程测量的要求,为变电设备调爬、带电水冲洗等防污工作的开展提供高精度的数据服务。     

Large-scale estimates of gross primary production on the Qinghai-Tibet plateau based on remote sensing data

Vegetation gross primary production (GPP) is an important variable for the carbon cycle on the Qinghai-Tibetan Plateau (QTP). Based on the measurements from 12 eddy covariance flux sites, we validated a light use efficiency model (i.e. EC-LUE) to evaluate the spatial-temporal patterns of GPP and the effect of environmental variables on QTP. In general, EC-LUE model performed well in predicting GPP at different time scale over QTP. Annual GPP over the entire QTP ranged from 575 to 703 Tg C, and showed a significantly increasing trend from 1982 to 2013. However, there were large spatial heterogeneities in long-term trends of GPP. Throughout the entire QTP, air temperature increase had a greater influence than solar radiation and precipitation (PREC) changes on productivity. Moreover, our results highlight the large uncertainties of previous GPP estimates due to insufficient parameterization and validations. When compared with GPP estimates of the EC-LUE model, most Coupled Model Intercomparison Project (CMIP5) GPP products overestimate the magnitude and increasing trends of regional GPP, which potentially impact the feedback of ecosystems to regional climate changes.     

夜间灯光数据支持下的广州市人口空间化

了解区域人口的空间分布,能够为城市精细化管理和城市规划提供有力的支撑数据,对提高城市发展水平有重要的现实意义。为此,本文以“珞珈一号”(LJ-1 01)夜间灯光(NTL)影像为基础数据,以广州市为研究区,结合人口估算模型等方法,开展基于NTL数据的人口空间化研究。结果表明:LJ-1 01 NTL数据能够有效地应用于人口空间化研究。人口空间化后,广州市人口分布具有显著的“一主中心,多核心”的特征,各区域内部的人口分布差异可被清晰地展示与区分。本文结果对城市规划与城市管理具有一定价值的辅助支撑作用。     

The theory and application of the structure light engineering surveying based on a laser theodolite with three freedoms of rotation

The concepts of “confining structure” and structure light are illuminated in this paper. A laser theodolite with three freedoms of rotation, which is aimed at “confining structure”, is developed. Various scanning modes and their mathematical models based on laser theodolite with three freedoms of rotation are discussed. According to the features of a huge object the structure light engineering surveying based on laser theodolite with three freedoms of rotation is determined as the main method in an actual application. The observation of four sound concrete posts and forced centering plates. Subsequently, it is transformed into the huge object coordinate system. The scanning mode with plumb plane is selected as the main mode in the whole work. And other assistant methods, such as close range photogrammetry and the method of using reflection sheet, are applied to the work of “scanning dead angle”. At last, a surveying accuracy estimation of this method is done and a surveying accuracy test is finished. It can be concluded that the structure light engineering surveying based on laser theodolite with three freedoms of rotation is considered to be an effective and applied method, and has many superiority to some other surveying methods in the work of surveying “confining structure”.     

基于逐日夜间灯光遥感的新冠肺炎疫情变化信息快速提取——以北京市为例

针对国内外日益复杂的疫情形势,本文以2020年6月北京疫情为例,利用NPP-VIIRS卫星的逐日夜间灯光数据,分析疫情受影响区域及疫情的控制与恢复状况,探索与人口密度等社会经济因素的关系。研究结果表明,逐日夜间灯光遥感可以有效提取疫情影响的区域范围及反映该区域受影响程度,所提取的受影响区域与国家划定的中高风险区域情况一致;同时基于逐日夜间灯光遥感能够及时监测疫情发展及疫情防控措施状况,区域夜间灯光强度随着疫情及防控的进展呈现明显的变化;平均夜间灯光损失强度及恢复强度同疫情暴发期区域人口密度均具有较强的相关性,相关性指标R²分别为0.97和0.91。本文研究结果表明逐日夜间灯光影像在快速提取新冠肺炎疫情变化信息方面有较大潜力。     

应用暗原色先验规律的遥感影像去雾技术

遥感影像去雾技术具有重大的应用价值。暗原色先验规律的提出为遥感影像的去雾提供了一种新的方法。根据遥感影像的特点,对应用暗原色先验规律的去雾方法进行了简化。实验证明,这种简化的方法对遥感影像的去雾处理能够在有效简化计算步骤的前提下取得良好的效果。     

Experimentation of structured light and stereo vision for underwater 3D reconstruction

Current research on underwater 3D imaging methods is mainly addressing long range applications like seafloor mapping or surveys of archeological sites and shipwrecks. Recently, there is an increasing need for more accessible and precise close-range 3D acquisition technologies in some application fields like, for example, monitoring the growth of coral reefs or reconstructing underwater archaeological pieces that in most cases cannot be recovered from the seabed. This paper presents the first results of a research project that aims to investigate the possibility of using active optical techniques for the whole-field 3D reconstructions in an underwater environment. In this work we have tested an optical technique, frequently used for in air acquisition, based on the projection of structured lighting patterns acquired by a stereo vision system. We describe the experimental setup used for the underwater tests, which were conducted in a water tank with different turbidity conditions. The tests have evidenced that the quality of 3D reconstruction is acceptable even with high turbidity values, despite the heavy presence of scattering and absorption effects.