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针对微波散射计资料的海面风场反演,本文首先利用QuikSCAT卫星散射计的近实时资料,借助荷兰皇家气象学会的SeaWinds散射计数据处理模式,在不同风速和海域的情况下,采用多解方案结合二维变分同化方法进行风向的模糊去除,达到消除解的不唯一性的目的,且对4种反演结果(低速风、中速风、高速风和近海岸风)与美国国家海洋和大气管理局卫星资料中心的近实时风场数据的对比分析,说明了该技术的有效性.在此基础上,对反演得到的中速风场利用广义变分最佳分析方法进行了调整,调整后的风场结构有了进一步的改善.此方法可为我国散射计资料反演海面风场的研究提供新的思路和方法. 相似文献
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Application of Tikhonov regularization method to wind retrieval from scatterometer data Ⅱ: cyclone wind retrieval with consideration of rain 下载免费PDF全文
According to the conclusion of the simulation experiments in paper I, the Tikhonov regularization method is applied to cyclone wind retrieval with a rain-effect-considering geophysical model function (called GMF+Rain). The GMF+Rain model which is based on the NASA scatterometer-2 (NSCAT2) GMF is presented to compensate for the effects of rain on cyclone wind retrieval. With the multiple solution scheme (MSS), the noise of wind retrieval is effectively suppressed, but the influence of the background increases. It will cause a large wind direction error in ambiguity removal when the background error is large. However, this can be mitigated by the new ambiguity removal method of Tikhonov regularization as proved in the simulation experiments. A case study on an extratropical cyclone of hurricane observed with SeaWinds at 25-km resolution shows that the retrieved wind speed for areas with rain is in better agreement with that derived from the best track analysis for the GMF+Rain model, but the wind direction obtained with the two-dimensional variational (2DVAR) ambiguity removal is incorrect. The new method of Tikhonov regularization effectively improves the performance of wind direction ambiguity removal through choosing appropriate regularization parameters and the retrieved wind speed is almost the same as that obtained from the 2DVAR. 相似文献
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黄思训 《中国科学B辑(英文版)》1989,(12)
In this paper we discuss the problem of a nonlinear gravity inertial wave of twodimensions and the possibility of solitary wave's existence. First of all, the existingcondition and analytic solution expression of shallow water waves are obtained by theapplication of the qualitative method of O. D. Es. We find that when the problem is de-generated, some physical values produce the nonlinear solitary wave, while other physi-cal values will be unbounded, so we consider that the nonlinear solitary wave for thesystem does not exist. Then we introduce concepts of the generalized energy (i. e. pseu-do-energy): when the pseudo-energy produces the tiny change at acting on a special ex-ternal effect, there will be solitary waves in this system. Finally, we obtain the repre-sentative of the nonlinear solitary wave which is different from KdV equation. 相似文献
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通过引入信息容量的概念,并借助Bayesian估计理论,给出了星载探测资料中所包含的如温度,湿度,O3,SO2,CH4等大气参数的信息容量的计算方案,该方法充分考虑了仪器各通道对反演参数的敏感性、各通道的观测误差特性以及背景场的误差特性;然后利用该方法对HIRS,AMSU,AIRS,IAIS四种仪器以及三种组合所包含的大气温度、湿度的信息容量进行了计算,得到十分有价值的结果,该方法预期在星载大气探测仪器的设计、各仪器的评估与比较、探测资料的
关键词:
大气探测资料
信息容量
权函数矩阵 相似文献
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借助于Bancroft方法快速决定全球定位系统中接收机的大概位置,可作为观测方程线性化的初值.采用最小二乘法来求解方程时,观测数据存在较大误差(即出现粗差)的情况下,最小二乘解会出现不稳定性,即问题呈不适定性.为了克服解的不适定性,引入了正则化方法,采用正则化方法及正则化参数最优选择来提高抗粗差能力.实验结果表明,利用这种定位方法的抗粗差能力有一定的改进,这对实时、快速定位有重要意义.
关键词:
全球定位系统
Bancroft方法
最小二乘法
正则化 相似文献
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黄思训 《数学物理学报(A辑)》1996,16(1):61-68
该文讨论具有非局部对流的一类反应扩散方程的脉冲解的存在性借助于方程的某种对称性,利用三维空间中追赶法技巧及拓扑方法,当参数ε在一定范围内,证明了方程的脉冲解存在性.最后给出波速C与人口速率和出生及死亡的动力学过程的相互关系. 相似文献
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本文考虑有外界热源情况下的非线性重力惯性内波,首先我们讨论了波解存在的条件及得到了解析解的表达式。然后我们利用拟能影响函数中的根与系数之间关系,导出一个无量纲的量M,利用M把周期解存在条件转化为M>2/3,当M→2/3时,就得到了区别于KdV方程的孤立波解。最后利用M我们建立了非线性波的波速公式,波速C与振幅,特征散度,M之间的关系,当波速公式向线性化波速公式退化时,我们发现当M≥l时系统呈线性效应;当2/3相似文献
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本文考虑一阶非线性超定组的拟 Riemann-Hilbert 问题,首先考虑全纯函数的拟 R-H问题,得到解的表达式,然后考虑线性问题的拟 R-H 问题,把问题化为标准化形式,指出一部分指标对讨论拟 R-H 问题已失去作用,最后讨论非线性问题,利用 Schwartz 公式及不动点定理,证明了在一定条件下问题是可解的. 相似文献