联合TOPEX/Poseidon与Geosat/ERM测高资料建立区域潮汐模型的研究

利用近十年的T/P测高数据来反演南海(8°~23°N,109°~120°E)九个主要分潮的潮汐参数,并计算了Geosat/ERM卫星对应的各主分潮的混叠周期及Rayleigh周期。根据潮汐参数提取的要求,选取了7个主分潮,为了克服混叠影响,将T/P沿迹点处的主要分潮间的5组差比关系引入到Geosat沿迹点处,并利用T/P提供的Sa模型去除Sa对M2的扰动影响。精度估计的结果表明,Geosat/ERM反演的潮汐参数的精度与传统的月分析结果的精度相近;因差比关系的捆绑,整个全日和半日潮族迟角偏差相近,这主要和Geosat/ERM的轨道设计有关。本文的方法可以应用于利用轨道调整后的T/P卫星的测高数据提取潮汐参数。

Establishment of regional ocean tide model by combination of TOPEX/ Poseidon and geosat/ERM altimeter data

Tidal parameters of 9 constituents in South China Sea(8°～23°N,109°～120°E) are estimated from about 10 years of T/P altimetry data.Alias periods and Rayleigh periods of principal tides under Geosat/ERM sampling are calculated.For overcoming the affect of aliasing,the following approach is adopted that only 7 principal constituents are chosen.Admittances calculated from the results of harmonic tidal analysis along T/P tracks are utilized to form the constrain equations.The heavy aliasing between M2 and annual constituent Sa is removed through the subtraction of Sa contribution,calculated with the T/P estimated results,from sea surface height.The derived tidal parameters are assessed through comparisons between the results both from the ascending and descending data on crossover points of both the T/P and Geosat tracks.The following conclusions are obtained:The accuracy of tidal parameters from Geosat/ERM are consistent with the accuracy of those from monthly tidal gauge observations.And because of the admittances' effect the deviations of phase lags of the whole diurnal and semidiurnal group are very close,which may be caused by the orbital design of Geosat/ERM.The method can also be applied to estimate tidal parameters from Jason-1 altimetry data.