Space and Time Filtering of Remotely Sensed Velocity Turbulence
Space and Time Filtering of Remotely Sensed Velocity Turbulence
复制标题
遥感速度湍流的时空滤波
DOI：
--
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
R. S. Lawrence
中科院分区：
文献类型：
--
作者：
A. White;R. Lataitis;R. S. Lawrence
众所周知，晴空多普勒雷达谱的宽度可以用来估计风的小尺度变化。为了准确地做到这一点，需要考虑对光谱宽度的所有贡献。最近，提出了一个用于校正多普勒频谱宽度的空间和时间滤波效应的近似公式。该公式假设独立的加性贡献的频谱宽度从雷达采样体积和有限的测量间隔的固有体积平均。在本文中的近似公式相比，一个确切的三重积分公式中的空间和时间的影响被证明是耦合在一个非线性的方式。所需的积分进行了数值评估，并在波数空间的整个尺度范围内进行，这与早期的工作不同，早期的工作使用各向同性惯性子范围谱形式的截断形式来获得简单的闭合形式表达式。Comparisons s.
Abstract It is well known that the width of a clear-air Doppler radar spectrum can be used to estimate the small-scale variability of the wind. To do this accurately requires that all contributions to the spectral width be accounted for. Recently, an approximate formula for correcting Doppler spectral widths for spatial and temporal filtering effects was proposed. The formula assumes independent additive contributions to the spectral width from the inherent volume averaging of the radar-sampling volume and the finite measurement interval. In the present paper the approximate formula is compared to an exact triple-integral formulation in which the spatial and temporal effects are shown to be coupled in a nonlinear fashion. The required integrations are evaluated numerically and are carried out over the full range of scales in wavenumber space, in contrast to earlier work, where truncated forms of isotropic, inertial-subrange spectral forms were used to obtain a simple, closed-form expression. Comparisons s...