便携式波长色散X射线荧光光谱仪及初步应用

介绍了SPECTROSCAN-U便携式波长色散X射线荧光光谱仪的技术指标及特点;使用该仪器并采用粉末样品压片制样测定了水系沉积物及土壤样品中的11个元素,得到了较好的精密度和准确度,为野外现场测试作了有益的尝试。     

高分遥感影像样本的结构特征分析

空间结构特征是高分影像最显著的特征之一,高分影像的各种地物类型都表现出不同的结构特征,这些结构既包括纹理的、几何的,也包括空间关系的,有效地利用高分影像的结构特征可以弥补光谱特征进行分类的不足.本文以高分影像的空间结构特征建模与信息的提取为主题,主要研究了空间自相关统计量的计算和利用空间自相关统计量对图像进行处理,以及...     

高精地图道路矢量化模型表达规则探讨

随着高精地图伴随自动驾驶技术出现,近些年来其生产技术日趋成熟。外业生产依托于三维激光扫描技术的广泛应用,高精度的基础数据的快速获取已实现。在高精地图内业生产端,其表现形式及表达规则由行业特定需求决定。高精地图的生产原理及应用大同小异,但无统一规则,使得高精地图的使用范围过小,不能一测多用。本文以道路要素的通用化表达为目的,分解出道路要素的道路模型、车道模型、地物模型,讨论各类模型的表达规则,以道路向量及车道向量及其拓扑关系建立表达粒度为车道级的路网关系。通过上述表达讨论使得高精地图的表达层次更加清晰,生产过程中依据性更强,统一规则表达的高精地图应用范围更广。     

贵州唐房-舍居乐地区“地物化遥”综合找矿标志及铅锌矿成矿预测

本文系统总结分析唐房-舍居乐地区地物化遥测量成果,以地物化遥综合成矿信息为基础,以化探信息为先导,总结分析区内铅锌矿床成因及综合找矿标志,用证据找矿信息量加权模型进行成矿预测和矿产查证工作,于该区圈定了摆布卡、陈家屋基、银厂口子、银厂坡、大黑山、小石桥、黑桃坪、九股水8个铅锌矿找矿远景区,提出了下步工作建议。     

Multilevel assessment of spatiotemporal variability of vegetation in subtropical mountain-hill region

The complex spatiotemporal vegetation variability in the subtropical mountain-hill region was investigated through a multi-level modeling framework. Three levels - parcel, landscape, and river basin levels- were selected to discover the complex spatiotemporal vegetation variability induced by climatic, geomorphic and anthropogenic processes at different levels. The wavelet transform method was adopted to construct the annual maximum Enhanced Vegetation Index and the amplitude of the annual phenological cycle based on the 16-day time series of a5om Moderate Resolution Imaging Spectroradiometer Enhanced Vegetation Index datasets during 2OOl-2OlO. Results revealed that land use strongly influenced the overall vegetation greenness and magnitude of phenological cycles. Topographic variables also contributed considerably to the models, reflecting the positive influence from altitude and slope. Additionally, climate factors played an important role： precipitation had a considerable positive association with the vegetation greenness, whereas the temperature difference had strong positive influence on the magnitude of vegetation phenology. The multilevel approach leads to a better understanding of the complex interaction of the hierarchical ecosystem, human activities and climate change.     

ERDAS I MAGINE V8.7新功能介绍——建立数字城市的地物纹理建模工具

ERDASIMAGINEV8.7中的立体分析模块 1.4版新增2个在立体像对的工程文件中创建带有纹理的 3维矢量纹理工具 ,这些纹理可以是真实世界照片或普通的贴图平铺纹理。·Block自动纹理化。前一版本的ERDAS立体分析工具提供捕获摄影测量工程文件立体影像的纹理信息 ,现在立体分析 1.4版提供为 3D矢量图形贴纹理的新功能。这些纹理可以作为纹理矢量标志文件 (扩展名为 .tvs)存储起来。纹理自动提取工具它通过移动 3D表面和摄影测量工程文件中每一个面的对应区域作为感兴趣面 ,计算最接近感兴趣表面几何视角 ,作为提取纹理的帧。     

基于LiDAR点云数据的地物几何特征提取与制图

从机载激光雷达数据自动识别地物对象,可提高数据的解译能力,成为快速、高效地形图测量、数字地籍、三维城市等数据获取的有效途径。本文基于机载Li DAR数据和遥感数据,进行快速数据获取与制图研究,充分利用激光雷达获取数据质量高的优势,通过高密度、不规则点云分析,构建建筑物、树木、地表、电力线等地物的离散几何模型,从而提高点云数据的分类精度及制图自动化。根据描述地物使用线和面以及纹理、颜色的方面的约束条件,通过构建点云的离散几何模型,对高维数据进行降维,达到高精度构建地物信息。应用法线估计法,计算邻域法线的各项异性的相似度,判断相邻网格是否属于一个平面,结合区域增长法构建规则地物的几何模型;采用自组织神经网络法对点云数据进行处理,利用自由曲面描述地物,以长春师范大学校园为例,实现了Li DAR点云数据的地物几何信息提取与制图。     

综合识别法去除风廓线雷达地物杂波的可行性研究

以杂波谱极小值连线的思想为基础,针对强风天气条件下的风廓线雷达地物杂波信号,提出一种综合识别杂波的去除方法,并与常规的地物杂波抑制方法相比较。结果表明:利用该方法对强风天气下的地物杂波有更好的抑制效果,水平风速得到了明显增强,与地面观测数据相比,雷达产品更趋于真实风速。     

第三次全国土地调查线状地物调查方法探讨

通过第二次、第三次全国土地调查执行的土地利用现状分类和土地调查技术规程对比分析,根据现有第二次全国土地调查成果和第一次全国地理国情普查成果等已有资料,提出在第三次全国土地调查中,应将村道纳入公路调查范围的观点,归纳已有资料,对利用方法、线状地物图斑构建方法和构建中可能遇到的问题提出处理方案,供开展三调工作的工程技术人员讨论。     

Satellite-based estimation of daily average net radiation under clear-sky conditions

ABSTRACT Daily average net radiation （DANR） is an important variable for estimating evapotranspiration from satellite data at regional scales, and is used for atmospheric and hydrologic modeling, as well as ecosystem management. A scheme is proposed to estimate the DANR over large heterogeneous areas under clear-sky conditions using only remotely sensed data. The method was designed to overcome the dependence of DANR estimates on ground data, and to map spatially consistent and reasonably distributed DANR, by using various land and atmospheric data products retrieved from MODIS （Moderate Resolution Imaging Spectroradiometer） data. An improved sinusoidal model was used to retrieve the diurnal variations of downward shortwave radiation using a single instantaneous value from satellites. The downward shortwave component of DANR was directly obtained from this instantaneous value, and the upward shortwave component was estimated using satellite-derived albedo products. Four observations of air temperature from MOD07_L2 and MYD07_L2 data products were used to derive the downward longwave component of DANR, while the upward longwave component was estimated using the land surface temperature （LST） and the surface emissivity from MOD1 l_L2. Compared to in situ observations at the cropland and grassland sites located in Tongyu, northern China, the root mean square error （RMSE） of DANR estimated for both sites under clear-sky conditions was 37 W m-2 and 40 W m-2, respectively. The errors in estimation of DANR were comparable to those from previous satellite-based methods. Our estimates can be used for studying the surface radiation balance and evapotranspiration.