基于Jason-3的海洋二号C卫星IGDR数据质量评估

Quality assessment of IGDR data of Haiyang-2C satellite by using Jason-3 altimeter data

为了评估国产第3颗海洋动力环境卫星海洋二号C卫星(HY-2C)高度计产品质量,选择HY-2C卫星15~56周期的IGDR数据进行统计分析与质量评估。首先分析了HY-2C卫星IGDR数据的完整性和有效性;然后以同期Jason-3卫星GDR数据为参考,利用标准差、均方根误差(RMSE)、皮尔逊相关系数等方法分析了两卫星之间的后向散射系数、有效波高、海况偏差、电离层延迟改正和湿对流层延迟改正等地球物理参数的日均值情况;最后统计了HY-2C卫星地面轨迹自交叉点海平面异常(SLA)不符值以及HY-2C和Jason-3之间的互交叉点SLA差值。结果显示:HY-2C数据完整性较高,有效性较好;与Jason-3对应的地球物理参数日均值一致性较好;地面轨迹自交叉点SLA不符值的RMSE为5.80 cm,平均值为0 cm;互交叉点SLA差值的RMSE为5.46 cm,平均值为1.84 cm。因此,HY-2C卫星整体运行稳定,精度与Jason-3接近,达到了设计要求。

This study chooses IGDR data of Haiyang-2C(HY-2C)from cycles 15-56 for statistical analysis and quality evaluation.The completeness and validity of the HY-2C satellite's IGDR data are first examined;then,the geophysical parameters such as backscatter coefficient,significant wave height,sea state bias,ionospheric delay correction,and wet tropospheric delay correction are compared between the two satellites by using standard deviation,root mean square error(RMSE),Pearson correlation coefficient,and other methods.Finally,the sea level anomaly(SLA)discrepancy values at the self-crossing point of the HY-2C satellite ground track and the difference in SLA at the intersection point of HY-2C and Jason-3 are computed.The findings indicate that the HY-2C has a high level of stability;the RMSE of the difference in SLA at self-crossing points is 5.80 cm,with an average value of 0 cm;and the RMSE of the difference in SLA at intersection points is 5.46 cm,with an average value of 1.84 cm.The accuracy is comparable to that of the Jason-3 satellite,and the HY-2C satellite fulfills the design accuracy criteria.