超高频雷达海洋表面流的探测结果与分析

Results and analysis of surface current based on UHF radar

近岸海域地形、海流复杂,而超高频雷达系统具有较高距离分辨率、小发射功率的特点,波长介于高频电磁波和微波之间,能同时提取海浪毛细波与重力波信息,与波浪作用比较敏感,能实现近海海洋动力参数的精细测量.不同于高频雷达回波谱,超高频雷达回波中一阶峰、二阶峰展宽严重并混叠在一起,难以划分一阶峰区域,因此,文中系统设计采用数字波束形成进行流速方位提取.雷达反演的流速结果与浮标数据的相关系数为0.88,但是均方根误差很大.通过分析,得出海洋表面流速不仅受到潮汐效应、地球自转的影响,当地风速在很大程度上也会影响表面流速的结论.

Ultra high frequency（UHF）radar has the characteristics of high range resolution and low-power,which can extract information of both capillary wave and gravity wave with the wavelength be-tween high frequency and microwave.It is possible to obtain precise monitoring of the coastal ocean dy-namics parameters by UHF radar,though the offshore topography and ocean surface current are complex. UHF radar is different from HF radar,since the first-order peak and second-order spectrum are indistin-guishable in the sea echo spectrum.It is difficult to extract first-order peak,therefore,multiple signal classification algorithm （MUSIC）is unavailable and digital beam-forming（DBF）is used in extracting the radial velocity.After a month,the radar and buoy datais highly correlated with a coefficient of 0.88,how-ever,the root mean square error is large.The results show that the velocity of the ocean surface is influ-enced not only by the tidal effect and the rotationof the earth,but also by the local wind speed.