基于目标函数分布特征的散射计海面风场反演方法  

A Wind Field Retrieval Method for Scatterometer Based on the Distribution Characteristic of its Objective Function

作　　者：解学通[1,2] 林明森[1] 陈克海[3] 田栋轩[4] 刘丽霞[4] 王小宁[4] 

机构地区：[1]国家卫星海洋应用中心,北京100081 [2]国防科技大学电子科学与工程学院ATR重点实验室,湖南长沙410073 [3]中国科学院南海海洋研究所,广东广州510301 [4]西安空间无线电技术研究所空间微波技术国防科技重点实验室,陕西西安710100

出　　处：《信号处理》2010年第7期968-973,共6页Journal of Signal Processing

基　　金：国家863项目(2007AA092201);国家863项目(2007AA12Z126);中国博士后科学基金(20080431403)

摘　　要：本文以SeaWinds散射计为例,针对圆锥扫描散射计星下点附近区域容易产生风向模糊问题,在分析其目标函数分布特征的基础上,对传统的最大似然风矢量反演算法和圆中数滤波算法进行了改进,提出了一种适合于圆锥扫描散射计的海面风场反演方法。该方法通过在目标函数分布较平坦的区域设置风向扩展区间,并使扩展后的更多风向解参与模糊去除来提高风向选择的准确性。利用200条轨道的SeaWinds散射计L2A数据和相应浮标数据,对本文给出的风场反演方法进行了验证。结果表明,该方法在无需外部辅助风场数据作为参考的条件下,能够使星下点附近区域的风向模糊性得到明显改善,从而证明了该方法的可行性。Aiming at the problem of high directional ambiguity in the nadir region of conically scanning scatterometer,taking SeaWinds as an example and in consideration of its objective function distribution characteristic,a modified wind field retrieval method suitable for this kind of scatterometer is presented in this paper,which is designed based on the traditional maximum likelihood wind vector retrieval algorithm and circle median filter algorithm. This method attempts to enhance the accuracy in selecting the true wind direction by extending the possible range of wind direction and allowing them to be taken into account in the ambiguity removal. Two hundred of SeaWinds Level 2A data files and some corresponding co-located buoy data are used to validate this retrieval method. The experimental results indicate that the retrieval method is feasible due to its capability of effectively improving the directional ambiguity existing in the nadir region without any external reference data to aid in wind field initialization.

关 键 词：SEAWINDS散射计 目标函数 风矢量反演 风向扩展区间 模糊去除 

分 类 号：TP722.6[自动化与计算机技术—检测技术与自动化装置] TP79[自动化与计算机技术—控制科学与工程]