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孙海丽  姚连璧  周跃寅  孙盼盼 《大地测量与地球动力学》2015,35(1):177-181

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戴华阳  岳冲  徐翀  阎跃观  邹定辉  刘杰  韩云春 《大地测量与地球动力学》2015,35(2):360-364

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地基微波辐射计探测大气边界层高度方法   总被引：4，自引：3，他引：1       下载免费PDF全文

刘思波  何文英  刘红燕  陈洪滨 《应用气象学报》2015,26(5):626-635

采用2013年中国科学院大气物理研究所香河大气综合观测试验站的地基微波辐射计和激光雷达观测数据,以激光雷达探测的大气边界层高度为参考,分别利用非线性神经网络和多元线性回归方法建立微波亮温直接反演大气边界层高度的算法,并对比两种方法的反演能力, 同时分析非线性神经网络算法在不同时段及不同天气状况下反演结果的差异。结果表明:非线性神经网络算法的反演能力优于多元线性回归算法,其反演结果与激光雷达探测的大气边界层高度有较好一致性,冬、春季的相关系数达到0.83,反演精度比线性回归算法约高26%;对于不同时段和不同天气条件,春季的反演结果最好,晴空的反演结果好于云天; 四季和不同天气状况的划分也有利于提高反演精度。  相似文献   

Correlation and characterisation of individual glass shards from tephra deposits using trace element laser ablation ICP‐MS analyses: current status and future potential     

Nicholas J. G. Pearce  Joanna S. Denton  William T. Perkins  John A. Westgate  Brent V. Alloway 《第四纪科学杂志》2007,22(7):721-736

Laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) is a high spatial resolution analytical method which has been applied to the analysis of silicic tephras. With current instrumentation, around 30 trace elements can be determined from single glass shards as small as ～ 40 µm, separated from tephra deposits. As a result of element fractionation during the ablation process using a 266 nm laser, a relatively complex calibration strategy is required. Nonetheless, such a strategy gives analyses which are accurate (typically within ±5%) and have an analytical precision which varies from ～ ±2% at 100 ppm, to ～ ±15% at 1 ppm. Detection limits for elements used in correlation and discrimination studies are well below 1 ppm. Examples of the application of trace element analysis by LA‐ICP‐MS in tephra studies are presented from the USA, New Zealand and the Mediterranean. Improvements in instrumental sensitivity in recent years have the potential to lower detection limits and improve analytical precision, thus allowing the analysis of smaller glass shards from more distal tephras. Laser systems operating at shorter wavelengths (e.g. 193 nm) are now more widely available, and produce a much more controllable ablation in glasses than 266 nm lasers. Crater sizes of <10 µm are easily achieved, and at 193 nm many of the elemental fractionation issues which mar longer wavelengths are overcome. By coupling a short wavelength laser to a modern ICP‐MS it should be possible to determine the trace element composition of glass shards as small as 20 µm and, providing sample preparation issues can be overcome, the determination of the more abundant trace elements in glass shards as small as 10 µm is within instrumental capabilities. This will make it possible to chemically fingerprint tephra deposits which are far from their sources, and will greatly extend the range over which geochemical correlation of tephras can be undertaken. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

我国月球激光测距研究与进展   总被引：2，自引：0，他引：2  

郑向明  郭锐  李语强  李祝莲  伏红林  熊耀恒 《天文研究与技术》2007,4(3):231-237

月球激光测距是国内外所瞩目的宏伟目标,代表着单光子探测技术的高峰。文中概述了全球月球激光测距的现状以及21世纪初月球激光测距的发展趋势;分析了我国开展月球激光测距的意义。最后介绍了云南天文台1.2m望远镜进行月球激光测距的发展战略和科学目标。  相似文献   

应用自适应相位补偿法减弱机载激光探测时湍流的干扰          下载免费PDF全文

叶修松  张传定  黄谟涛  吴星  王爱兵 《海洋测绘》2009,29(4):12-13

从理论上推导了自适应相位补偿法的基本原理，详细分析了探测光波在经过湍流前后的相位畸变关系。得出了为能补偿掉湍流影响所要求辐射孔径上需要的场强。  相似文献   

用中国卫星激光测距资料解算地球定向参数   总被引：1，自引：0，他引：1  

朱元兰  冯初刚  张飞鹏 《天文学报》2006,47(4):441-449

利用我国SLR网卫星Lageosl的激光测距资料独立测定地球定向参数EOP的可能性和可达到的精度,选取了2001年4月19日—5月30日,2001年9月1日—10月30日这两时段国内SLR网对Lageosl卫星激光测距资料,用SHORDE软件估算地球定向参数,并在同样的时间段内用全球的Lageosl卫星的激光测距资料也测定地球定向参数,分别将两序列的地球定向参数与IERS的EOPc04序列进行比较,其外符精度分别为：X_p、Y_p4—5mas、D_r-0．32ms(用目内资料解算的),X_p、Y_p1—0．35mas、D_(r1)-0．03ms(用全球的激光资料解算的)．  相似文献   

基于多波长激光吸收光谱技术的气体浓度与温度二维分布遗传模拟退火重建研究   总被引：1，自引：0，他引：1  

李宁  翁春生 《海洋学报》2010,32(10):6914-6920

利用可调谐半导体激光吸收光谱技术实现气体浓度温度二维分布重建.设计了气体浓度温度二维分布重建测量系统,采用四路波分复用技术以减少投影光路布置数量和增加气体吸收测量信息.针对于图像重建过程中建立的非线性投影方程组,将遗传算法与模拟退火算法相结合进行求解,在实现全局最优搜索基础上提高算法搜索效率.建立燃烧环境下H₂O浓度温度二维分布模型,借助于近红外波段1.3—1.5 μm范围内4条H₂O气体吸收谱线,利用数值模拟计算方法进行了气体分布重建,重建结果与模型符合得很好  相似文献   

基于GIS与三维激光扫描的古建筑保护研究   总被引：1，自引：0，他引：1  

邢昱  范张伟  吴莹 《地理空间信息》2009,7(1):88-91

以三维激光扫描点云数据作为基础数据，以河南大学明伦校区近代建筑群为研究对象，结合地理数据库和三维建模技术，建立了古建筑数据库利用ArcGIS Engine二次开发平台，设计了基于GIS的古建筑数字化保护系统，并同时探讨了系统建立过程中的若干技术问题：研究结果说明，基于三维激光扫描和GIS的新技术手段，为古建筑的数字化保护带来了新的契机。  相似文献   

Documentation of Istanbul Historic Peninsula by Kinematic Terrestrial Laser Scanning     

Thomas P.  Kersten  Gürcan  Büyüksal&#;h  &#;brah&#;m  Baz  Karsten  Jacobsen 《The Photogrammetric Record》2009,24(126):122-138

Although the Historic Peninsula of old Istanbul was added to the UNESCO World Heritage List in 1985, complete documentation of this important area has not yet been carried out. In 2006 the Istanbul Metropolitan Municipality's Historical Environment Protection Directorate initiated the "Historic Peninsula Project", which covers an area of 1500 ha and includes approximately 48 000 buildings in crowded and frequently narrow streets. BİMTAŞ, a company owned by the Municipality, immediately started the documentation of all buildings in the project area using terrestrial laser scanning. This created the challenge of building up an efficient production environment with new high-end technology to fulfil the requirements of this project in a very short timeframe of 2 years. This paper describes the entire production environment for documentation of all buildings, detailing the frequent adaptations of the process resulting from learning on the job. Although the data acquisition and mapping environment was established in the course of production, it was always essential to optimise the technical solutions in order to meet the requirements for data quality and delivery deadlines. Only 80 ha of the required 1500 ha was completed using static scanning during the first 6 months, thus requiring a change from static to mobile terrestrial laser scanning in order to accelerate the work and to conclude the scanning phase for the remaining major area within 3 months.  相似文献