Jason-2卫星阈值重跟踪算法比较

选取Jason-2卫星在中国南海北纬15°~18.5°范围1 276个波形数据,依据Threshold算法和SeaIce算法对波形进行重跟踪,得到不同阈值水平下的距离改正结果。结果表明:当星下点轨迹靠近陆地时,距离改正值增大。然后,依据不同方法、不同阈值水平对应的距离改正值对卫星观测的海面高实施修正,得到相应的海面高结果。作为验证,选取法国国家太空研究中心(CNES)发布的海面高作为外部检核条件。将修正后的海面高与CNES公布的海面高进行较差比较,较差值的统计分析表明:SeaIce重跟踪算法在阈值水平为50%时,差值的标准差明显小于其他方法的计算结果。

Threshold Algorithm Comparison for Jason-2

The 1 276 waveform data of Jason-2,which from 15 degree north latitude to 18.5 degree in the South China Sea,were selected in the paper.The distance corrections of different threshold levels were computed based on Threshold algorithm and SeaIce algorithm.The results showed that when satellite tracking was close to the land,the distance corrections increased.Then,modified SSH(sea surface hight) was obtained according to the results above.As a verification,SSH released by Centre National d'Etudes Spatiales(CNES) was selected as the external checking condition.Compared with the results published by the CNES,the STD(standard deviation) of SeaIce method was lower than those of other methods when the threshold level was 50％.