机载超低频雷达探测海洋内波

The Method of Detecting Ocean Internal Waves through Airborne Ultra Low Frequency Radar

机载超低频雷达探测海洋内波是海洋内波探测的新方法。海洋内波使海水电导率垂向分布发生扰动,当雷达发射的电磁波探测信号传播到内波扰动界面,电磁信号发生反射,部分反射信号再次穿透海面传播到空气中并被天线捕捉,雷达系统通过处理内波界面处的反射信号并抑制海面的反射信号实现对海洋内波的探测。根据麦克斯韦方程和海水的物理性质,推导出超低频电磁波在海水中的传播特性,研究海水温度、盐度变化对海水电导率的影响,根据KDV方程解和垂向特征函数解构造了海洋内波垂向结构,仿真了雷达接收到的海表面处、内波界面处的反射信号及其延迟时间,仿真结果表明,可以使用该方法探测海洋内波。

The use of airborne ultra-low frequency radar functions as a new method for detecting ocean internal waves which brings about disturbance of the vertical distribution of seawater conductivity. When electromagnetic waves emitted by radar propagate to the perturbation interface of internal waves, electromagnetic signal reflection occurs, with a portion of reflected signals once again passing through the sea surface and spreading into the air, which are then received by the antenna. The radar system can detect ocean internal waves by processing the reflected signals from the interface and curbing the reflected signals from the sea surface. The propagation characteristics of ultra-low frequency electromagnetic waves in seawater are derived based on Maxwell 's equations and the physical properties of seawater, and research was conducted on the effects of seawater temperature and salinity variation on seawater conductivity. The vertical structure of ocean internal waves is constructed based on the solutions of the KDV equation and vertical characteristic function. The reflected signals received by radar from the sea surface and interface of internal waves and their delayed time are simulated, which results in the conclusion that the method is appropriate for detecting ocean internal waves.