L波段探空仪温度资料误差分析   总被引：13，自引：2，他引：13  

陶士伟  陈晓红  龚建东 《气象》2006,32(10):46-51

我国探空观测业务已逐步用L波段探空仪取代59型探空仪。为了解L波段探空仪观测质量，利用观测资料减模式背景场的差（简称OMB）的统计分析技术和贝塞尔函数拟合法分离观测误差技术，分析了2005年35月我国36个L波段探空仪探测的温度误差特性。结果表明，L波段和59型的OMB平均偏差差别不大，一般都在0．2℃之内。而温度随机误差在500-300hPa减小约0．2℃，在00时300hPa以上，有更明显的减小，达0．4℃，约占59型观测误差的四分之一。  相似文献   

一种稳健的干涉相位解模糊新方法     

靳国旺徐青  何钰刘继东  杨韫澜 《测绘科学与工程》2006,26(3):12-16

相位解模糊是影响雷达干涉测量技术应用的一个瓶颈问题，本文提出了采用质量图区域生长对干涉低相干区进行屏蔽并对屏蔽区相位采用移动曲面拟合的干涉图解模糊方法。通过对由多种不同雷达干涉数据获取的干涉图进行解模糊处理，验证了该方法的稳健性和可靠性。  相似文献   

Cosmic ray and hydrogen distributions and cosmic gamma — rays     

Zhou Da-zhuang

K. K. Tang 《Chinese Astronomy and Astrophysics》1991,15(4):416-422

We calculate the spectrum of the diffuse cosmic gamma ray in the single and double leaky box models for several galactic distribution laws of cosmic rays and hdydrogen. The results show that LI Ti-pei's distribution law for the cosmic rays is the best and that the number of interstellar hydrogen molecules should be less than Gordon's value divided by 1.7. The observed spectrum of gamma rays can be reproduced by a suitable choice of the galactic distributions within certain ranges.  相似文献   

Steady-state vertical distribution of cohesive sediments in a flow   总被引：1，自引：0，他引：1  

Martin Sánchez  Patricia Grimigni  Yann Delanoë 《Comptes Rendus Geoscience》2005,337(3):357-365

Settling velocity of diluted suspended aggregates is examined under steady-state conditions. It is shown that if the local settling velocity of the suspended mass of sediments at the bottom is gamma distributed, then, the vertical variation of the local mean settling velocity $\overline{W}$ is proportional to a power $1/r$ of the local concentration C, where r is the gamma distribution parameter. That is a consequence of the suspended-sediment sorting produced by the vertical dynamics. The parameter r characterizes the range of settling velocity values for all the aggregates simultaneously in suspension. To cite this article: M. Sánchez et al., C. R. Geoscience 337 (2005).  相似文献   

High energy gamma-rays from cygnus X-3     

Tipei Li  Mei Wu 《Chinese Astronomy and Astrophysics》1989,13(4):383-385

Simultaneous observations by the ESA satellite COS-B show that the 2–12 keV X-rays and 150–5000 MeV gamma-rays of Cyg X-3 are negatively correlated. A clear gamma-ray image of Cyg X-3 can be obtained between June 1977 and June 1980, when the X-ray emission was low, to yield a flux of P(E > 100MeV) ~ 1 × 10⁻⁶cm⁻²s⁻¹.  相似文献   

Stochastic modeling of daily precipitation in China   总被引：6，自引：1，他引：6  

LIAO Yaoming  ZHANG Qiang  CHEN Deliang   《地理学报(英文版)》2004,14(4):417-426

1IntroductionWeather Generator (WG) is a stochastic model that can be used to simulate daily weather based on parameters determined by historic records. Precipitation, maximum temperature, minimum temperature, radiation and more can all be simulated by WG. Recently WG has gained renewed attention and has been extensively applied in studying impacts of climate change on a variety of systems including ecosystem and risk assessment. Specifically, it has been used in the following ways. 1) WG …  相似文献   

机载三线阵CCD摄影中心轨迹及姿态拟合的半参数法     

孙海燕  李瑞明  闫利 《武汉大学学报(信息科学版)》2003,28(6):706-709

只要给出摄像瞬间摄像中心的位置和摄像平台的姿态，通过机载三线阵CCD获取的影像就可以直接解算地面点坐标。拟合摄像中心的位置函数和摄像平台的姿态函数是机载三线阵CCD摄影测量的最基本问题。针对由GPS／INS得到的摄像平台位置和姿态观测值，提出了半参数拟合法。模拟计算表明，这种方法可以有效地克服对飞行轨迹及姿态的先验数学模型的模型误差，从而达到较高的精度。  相似文献   

GPS城区地籍控制网的精度分析及高程拟合研究   总被引：2，自引：0，他引：2  

高伟  齐建国 《国土资源遥感》2003,14(4):42-45

对某县城GPS城区地籍控制网进行了数据处理和精度分析,采用二次多项式曲面拟合函数,获得测区的高程异常模型,把GPS控制点的大地高转换为正常高,最后拟合点和检核点的精度达到了4等水准测量的精度要求,满足了地籍测量工作的需要。  相似文献   

设计洪水频率曲线数学适线法的比较分析     

费永法  平克建 《水文》2001,21(6):26-28

运用全国91座大型水库洪水资料,比较分析了绝对值最小准则适线、离差平方和最小准则适线、概率权重矩法和双权函数法等适线结果与设计成果采用值(一般为目估适线结果)的差别.结果显示,无论是频率曲线参数,还是各频率洪水设计值,离差平方和最小准则适线结果均与采用成果的差别最小,多数(56%～87%)水库设计值的相对误差在±5%以内,绝大多数(79%～93%)水库设计值的相对误差在±10%以内.  相似文献   

Models for Fitting Gravimetric Geoids and GPS Results     

EssamGhanem  LIJiancheng 《地球空间信息科学学报》2002,5(1):28-30

The aim of this investigation is to study how to use a gravimetric(quasi) geoid for levelling by GPS data in an optimal way.The advent of precise geodetic GPS has made the use of a technique possible,which might be called GPS- gravimetric geoid determination.In this approach,GPS heights above the reference ellipsoid are determined for points whose levelled (orthometric) height H is above sea level people have already surveyed;for these points,we thus have the values of the geoid undulation N.These values are then used to constrain the geoid undulations N‘ obtained from the gravimetric solution.  相似文献