高频GNSS单点测速数据提取海浪参数方法研究

High frequency GNSS single station velocimetry technology can provide high resolution marine surface displacement information,which introduce a new data source for the wave measurement. However, the precision of GNSS single station velocity measurement with using the raw Doppler observations is not stable, which is not very good to meet the requirements of wave measurement. On the other hand, based on the high-frequency carrier-phase derived Doppler observations, the precision of GNSS single station velocity measurement is more stable. High-frequency GNSS observation data of single station includes various types of noise, which can not completely meet the requirements of marine tide and wave observations. To solve this problem, this project intends to carry out the study of theory and method that using precise GNSS single station velocimetry data to extract wave related information. In this project, Doppler data derive from carrier phase will be used by single station velocimetry technology to obtain three-dimensional velocity. After solving single station velocity determination, we will aim to obtain the marine surface displacement, and explore effective method of wave and tidal signal separation, focus on adaptive Kalman filter in the marine environment and the directional ocean wave spectrum calculation based on GNSS three-dimensional velocity vector. Through this study we expect to get the wave parameters such as wave height, period and wave direction.

利用高频GNSS单点测速数据可以获取高分辨率的瞬时海面波动信号,这为海浪测量研究提供了一种新的数据源。然而目前高频GNSS单点原始多普勒测速精度不稳定，尚不能很好的满足海浪测量的要求，而利用载波相位历元间差分求取的导出多普勒值进行GNSS单点测速精度更加稳定。因此本项目拟针对性的开展基于高频GNSS单点导出多普勒测速技术的海浪参数提取方法研究，具体内容包括：海洋动态环境下高精度单点GNSS导出多普勒测速模型构建、基于天顶方向速度数据的高精度海浪波动信号提取以及基于GNSS三维速度矢量的海浪谱估计。通过对关键技术的突破来进一步提高海洋动态环境下GNSS单点测速精度，探索海浪波动信号提取技术，结合海浪谱分析技术以期获得波高、周期以及波向等海浪参数。

全球导航定位系统(GNSS)正蓬勃发展，GNSS具有全天候、高精度等诸多优势，已经被广泛应用于地壳运动监测、高层建筑动态特征监测等领域，但在海洋领域尤其是海浪及潮位监测领域中，GNSS技术的应用相对较少。波浪和潮汐作为海洋中重要的运动现象，对人类在海上活动及近岸活动有着巨大影响。本项目研究了利用高频动态GNSS技术反演海浪参数及潮位变化信息的方法，主要做了以下几方面工作：.（1）基于单点GNSS测速的波浪测量.将GNSS载波相位数据通过历元间差分，建立了高精度的GNSS单点测速模型。通过滑动平均处理，消除了速度积分运算带来的“零点漂移”，获取了高精度的海面波动位移。结合谱分析技术进行了海浪功率谱计算，求取了波浪周期及波高等参数，与现有的波浪测量仪及潮位测量仪比对结果一致性较高。只依靠单一GNSS传感器的海浪测量方法，因其不用借助其他外部传感器便可以获取测点处的位置信息以及海浪参数，所以其维护成本大大降低。另外，采用GNSS单点测速方式不受作业距离限制，且测速精度不受位置精度制约，尤其适合远海应用。.（2）GNSS在航潮位测量.结合GNSS动态定位技术（RTK、PPP、PPK多种模式）进行了船载GNSS定位数据的解算，并对高程变化进行了姿态改正，通过门限滤波消除了随机噪声和波浪影响，获得了各测量点基于WGS84椭球的潮位变化。利用近岸控制点资料，基于EGM2008模型构建了似大地水准面精化模型，实现了高程转换，获得了基于当地验潮基准的潮位变化。然后，将结果应用于多波束水深测量的潮位改正，该方法大大提高了水深测量效率及潮位改正精度。.