MODIS气溶胶光学厚度产品在地面PM_(10)监测方面的应用研究

利用MODIS(中分辨率成像光谱仪)两年的气溶胶光学厚度(AOD)产品与北京地区API转化得到的PM10质量浓度、北京大学站点直接监测的PM10质量浓度以及香港元朗站点监测的PM10质量浓度做相关性分析,发现二者的直接相关程度较低。将AOD除以气溶胶季节标高,得到地面消光系数,与地面PM10质量浓度相关性提高。对地面消光系数进行相对湿度订正,得到计算的质量浓度,与地面实际观测的PM10质量浓度相关性进一步提高。经过两年时间资料的对比分析,证实气溶胶遥感光学厚度经过垂直和湿度影响订正后,可以应用于地面PM10监测。     

最近邻河道相对高度及其在中国洪水淹没制图中的应用

基于国际上由数字高程模型（digital elevation model,DEM）衍生的最近邻河道相对高度（height above nearest drainage,HAND）概念,采用STRM DEM数据派生了中国1000和250 m水平分辨率的HAND数据集,并将HAND数据集应用于洪水淹没制图,建立了河道水位相较枯水期上涨1~10 m情景下的中国河道型洪水淹没图库．进一步以淮河一级支流淠河2020年7月大洪水为例,采用遥感提取及HEC-RAS计算的淹没范围,验证了基于HAND绘制的淹没图．结果表明,HAND相对于经典的DEM能够补充提供局地地形信息,基于HAND的淹没制图方法具有可行性和合理性．本文计算的中国HAND数据集可为地理学相关领域的研究提供凸显局地特征的地形数据,建立的基于HAND的淹没图库可为中国的洪水淹没制图工作及洪水风险管理提供参考．      

谈MapGIS在地质制图中的应用及其存在的问题

随着国家经济的飞速发展,地理学、计算机学、制图学及数据库技术的不断发展和应用,为了科学、有序地部署和实施全国危机矿山接替资料找矿工作,国土资源部组织开展了全国主要固体矿产大中型矿山资源潜力调查工作.MapGIS软件除了制图功能,在数据的提供上有很大的用处,可以将数据进行深入的整合、统计,并对其进行分析,为技术人员提供相关参数,大大提高了工作效率节约了人力资料,MapGIS技术成为资源潜力大调查数据库建立中最基本的制图平台.     

Classification of vegetation in North Tibet Plateau based on MODIS time-series data

Based on the 16d-composite MODIS （moderate resolution imaging spectroradiometer）-NDVI（normalized difference vegetation index） time-series data in 2004, vegetation in North Tibet Plateau was classified and seasonal variations on the pixels selected from different vegetation type were analyzed. The Savitzky-Golay filtering algorithm was applied to perform a filtration processing for MODIS-NDVI time-series data. The processed time-series curves can reflect a real variation trend of vegetation growth. The NDVI time-series curves of coniferous forest, high-cold meadow, high-cold meadow steppe and high-cold steppe all appear a mono-peak model during vegetation growth with the maximum peak occurring in August. A decision-tree classification model was established according to either NDVI time-series data or land surface temperature data. And then, both classifying and processing for vegetations were carried out through the model based on NDVI time-series curves. An accuracy test illustrates that classification results are of high accuracy and credibility and the model is conducive for studying a climate variation and estimating a vegetation production at regional even global scale.     

一种实时数据处理的软硬件算法研究

针对某中分辨率成像光谱仪遥感图像数据的特点,在研究基于局域纹理特征适合空间应用图像无损压缩技术的基础上,进行无损解压缩算法的设计,阐述了如何采用并行处理和流水线技术优化算法,实现算法到VLSI结构的优化映射,研制无损解压缩专用芯片,该芯片可以不低于16 Mbps的速率实时处理压缩数据,进行无损解压.     

青藏高原东部及周边地区热红外背景场特征

背景场是卫星红外地震异常研究的基础.利用均值法构建红外背景场,并从季节、纬度和地形等方面分析了强震高发的青藏高原东部及其周边地区的卫星红外辐射背景场特征.结果显示,青藏高原东部及其周边地区红外背景场具有明显的季节年变化特征,但不同地区的年变化趋势不完全一样;红外背景场具有纬度特征,高纬度地区年变幅度大,低纬度地区年变幅...     

Estimation of net surface shortwave radiation from land surface temperature in regional scale

The method to estimate NSSR (net surface shortwave radiation) from LST (land surface temperature) in regional scale is discussed. First, an elliptical model between the time series of normalized LST and NSSR was developed using the daily evolution of LST and NSSR. Second, time series of LST and NSSR were simulated by common land model (CoLM) and were proved to be of high accuracy. On the basis of these, a non-linear least square ellipse fitting using the genetic algorithm method was used to fit the normalized LST and NSSR. Finally, LST was inverted using MODIS (moderate resolution imaging spectroradiometer) data with the split-window algorithm, and the regional NSSR was then estimated with LST and an elliptical model. The validation result shows that the derived average NSSR of 50×50 pixels of MODIS data was quite close to the observed data, and the distribution was reasonable, which indicates that the proposed method was capable of estimating NSSR on a regional scale.     

青藏高原东缘岩石圈及软流圈结构

青藏高原东缘岩石圈及软流圈结构的研究是认识该区域地壳上地幔的构造形变及高原内部物质向东运移的重要手段。通过搜集四川区域数字地震台站和野外临时地震台站记录的观测资料,采用接收函数共转换点(CCP)偏移叠加成像方法对青藏高原东缘深部结构研究。研究结果揭示:青藏高原东缘的地壳厚度比四川盆地的地壳厚度大10~20km;在青藏高原东缘与四川盆地的过渡地带,莫霍面处存在大幅度的垂向错断和变形。从青藏高原东缘到四川盆地,岩石圈与软流圈分界面(LAB)显示出深度逐步增加、410km间断面深度则有变浅的趋势。在地壳的下界面和LAB界面间以及LAB界面与410km间断面间也存在多条不连续的分层。青藏高原东缘和四川盆地的LAB界面的下方都有明显的低速层分布,但它们之间存在差别,四川盆地的LAB界面的下方低速层分布较为完整,而青藏高原东缘LAB界面下方的低速层分布中可见离散的高速块体分布。青藏高原东缘与四川盆地深部结构的明显差异,体现了该地区的深部地球动力学背景的复杂性。     

基于STBC MIMO-OFDM系统特性的并行选择映射算法

正交频分复用(OFDM)技术是第四代移动通信系统的核心技术之一,但是高峰均功率比(PAPR)问题的存在一直是该技术实用化的主要障碍.针对该问题,证明了基于空时分组码的MIMO-OFDM系统中,共轭信号具有相同的峰均功率比特性,提出了基于相同峰均比特性的并行选择映射算法.所提算法不仅保持了已有并行选择映射算法的峰均比降低性能,同时有效地减少了算法复杂度,降低了边带信息的传输量,提高了系统的频带利用率.仿真实验结果证明了所提算法的有效性.     

SLAM中融合形状上下文和随机步进的图匹配数据关联算法

提出了一种在非确定环境下求解SLAM数据关联问题的图匹配算法. 算法建立了SLAM中数据关联的图论模型,对图模型节点提取了不依赖位置信息的形状上下文特征(shape context,SC),最后通过二次加权随机步进算法(reweighted random walks,RRW)得到图匹配问题的优化解. RRW&SC图匹配算法充分利用了路标间的拓扑结构关系以及路标间的形状结构,极大地扩展了数据关联时所依据的几何信息量. 仿真实验结果表明,与传统算法相比,该算法能有效处理SLAM中噪声干扰增加、机器人迷失、路标被动态遮挡等不确定程度高、歧义性大环境中的数据关联.      

河北彭家沟银矿床地质特征及控矿因素

论述了彭家沟银矿床的地质特征及控矿因素。     

Integrated Evaluation Model for Eco-Environmental Quality in Mountainous Region Based on Remote Sensing and GIS

Based on Remote Sensing （RS）, Geographic Information System （GIS）, and combining Principal Component Analysis, this paper designed a numerical integrated evaluation model for mountain eco-environment on the base of grid scale. Using this model, we evaluated the mountain eco-environmental quality in a case study area-the upper reaches of Minjiang River, and achieved a good result, which accorded well with the real condition. The study indicates that, the integrated evaluation model is suitable for multi-layer spatial factor computation, effectively lowing man＇s subjective influence in the evaluation process; treating the whole river basin as a system, the model shows full respect to the circulation of material and energy, synthetically embodies the determining impact of such natural condition as water-heat and landform, as well as human interference in natural eco-system; the evaluation result not only clearly presents mountainous vertical distribution features of input factors, but also provides a scientific and reliable thought for quantitatively evaluating mountain eco-environment.     

基于证据权重法的辽西钼-多金属矿床评价预测

针对目前矿业勘探开发中的资源潜力快速评价问题,以基于GIS的数据驱动模型证据权重法为主导,结合基础地质资料,从遥感影像中提取相关构造、矿化及蚀变信息.采用中上寒武-奥陶统、义县组、雾迷山组、燕山期花岗岩、粘土蚀变、二价铁强度、三价铁强度和构造强度等8个因子评价辽西钼-多金属矿床,并通过X2独立性检验证明其在数学上的可行性,且在3大矿集区符合的基础上,评价预测出高家岭、红崖子两个成矿远景区.