海洋温度锋区后向散射系数仿真与特性研究  

Research and Simulation of Backscattering Coefficient Characteristic Across Ocean Thermal Fronts

作　　者：许素芹[1] 李婷婷 陈捷[1] 于振涛[1] XU Su-qin;LI Ting-ting;CHEN Jie;YU Zhen-tao(Navy Submarine Academy,Qingdao 266199,Shandong Province,China)

机构地区：[1]海军潜艇学院

出　　处：《计算机仿真》2019年第10期214-218,297,共6页Computer Simulation

摘　　要：海洋温度锋在海洋中普遍存在,其明显特征为海水温度梯度较大,引起锋区海气温差变化,产生大气在锋区的局部环流,造成风场变化.基于海气温差造成的大气不稳定建立了摩擦风速模型,分析了海气温差对摩擦风速的影响.同时以摩擦风速为中间变量,基于主动微波遥感经典Bragg后向散射系数模型,采用EH海浪谱,实现了对海洋温度锋区后向散射系数σ0的仿真,并讨论了波段、极化方式、风速及大气稳定度条件对温度锋区σ0的影响.仿真结果表明:VV极化、较大频率、锋区两侧大气稳定度不同对海洋锋探测最为有利.海洋锋区σ0的仿真实现,有利于更好地模拟海洋锋在合成孔径雷达(Synthetic Aperture Radar,SAR)中的成像仿真,同时为主动雷达遥感探测海洋锋奠定了理论基础.Thermal fronts are common ocean phenomena with the obvious characteristics of strong temperature gradient. The strong gradient causes the change of the air -sea temperature differences at both sides of the front,leading to the local circulation and wind field change in the frontal zone. Friction wind speed model was established based on the thermal unstable stratification,according to which the influence of air-sea temperature differences on friction wind speed was analyzed. Friction wind speed was selected to be the intermediate variable to simulate the backscattering coefficient in the frontal zone,using the classical Bragg backscattering model and E_H ocean wave spectrum,and the influences of wave band,polarizations,wind speed and atmospheric stability on σ^0 in the frontal zone were discussed. Simulation results indicate that VV polarization,higher frequency and different atmospheric stability at different sides of the front were most favorable to ocean front detection. The simulation of σ^0 in the frontal zone helps to simulate the ocean fronts in SAR images better and lays the theoretic foundation for ocean front detection by active radar.

关 键 词：海洋温度锋 后向散射系数 摩擦风速 仿真 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]