GNSS浮标海面高测量中海浪的影响分析

Analysis of the Influence of Ocean Wave on the Sea Surface Height Measured by GNSS Buoy

以骑浪式浮标为对象,研究了海浪对于GNSS浮标测量海面高的影响。以单向规则波的形态简化模拟了海浪以及GNSS浮标随海浪的运动过程。在某固定海况条件下,比较了浮标天线参考点高不同时海面高测量误差;在浮标天线参考点高固定的条件下,比较了不同海况时海面高测量误差;给出了GNSS浮标在卫星高度计定标应用中的建议。结果表明:浮标测量海面高误差与天线参考点高成正比,海浪周期越长、波高越小时,测量误差越小;天线参考点高为5 cm,海浪振幅为1 m、周期为7 s、传播速度为5 m/s时,测量海面高平均比实际海面高低0.4 mm;相同浮标在小于3~4级的海况条件下,由海浪引起的海面高测量偏差约在1 mm以内,对于卫星高度计定标工作而言,该误差影响可以忽略。

The influence of ocean wave on the sea surface height（ SSH） measured by waverider GNSS buoy was studied. Ocean wave was simply modeled as regular wave in single direction,and the movement of GNSS buoy with ocean wave was numerically simulated. SSH errors measured under different antenna reference point（ ARP）heights were compared respectively. Giving fixed ARP height,SSH errors were compared under different ocean conditions. Based on the above analysis,suggestions of using GNSS buoy in satellite altimeter calibration were proposed. The results show that SSH measuring error is proportional to ARP height. The longer wave period and the shorter wave height is,the smaller SSH error is. When the ARP height is 5 cm,wave amplitude is 1 m,wave period is 7 s and spreading velocity is 5 m/s,the measured SSH is 0.4 mm lower than the truth value by average. During low sea states（ less than 3 to 4 on the Beaufort scale）,the measuring error of the same buoy caused by ocean wave is smaller than 1 mm,which can be omitted in satellite altimeter calibration.