海南近海Envisat测高波形重构海面高质量评价

Assessment of Retracked Envisat Altimetry Sea Surface Heights near Hainan Coastal Ocean

摘要:

以海南近海（14~20°N，108~120°E）为研究区域，采用四种波形重构算法（Ocean1算法，阈值（Threshold）算法，重心偏移（OCOG）算法和Beta5参数算法）对Envisat高度计RA2第20周期八条轨迹的测高波形数据重新进行计算，并对波形重构后的海面高（SSH）精度进行评价.结果表明：波形重构算法能显著提高测高海面高数据质量，且重构后海面高的空间分辨率有较大改善.其中Threshold 50%算法的重构精度最高，Ocean1算法的精度也较好.Threshold 50%算法的结果最为稳定，比其他三种算法更适合于海南近海的测高波形重构.

关键词:卫星测高; 波形重构; 近岸海域; 海面高(SSH); 评价指标

Abstract:

Four waveform retracking algorithms, Ocean1, Threshold, Offset center of gravity (OCOG), and Beta 5 parameter retracking algorithms, were used to retrack the Envisat waveforms over the Hainan coastal ocean and the accuracy of retracked sea surface heights (SSHs) were assessed. The results indicate that the accuracy of the SSHs can be improved by waveform retracking algorithms and the spatial resolution of the retracked SSHs is significantly improved. The accuracy of the Threshold 50% Algorithm is the highest and the Oceanl Algorithm also performs better than the other two. The Threshold 50% Algorithm is the most stable retracking method and more suitable for the Envisat waveform retracking over Hainan coastal ocean.

Key words:satellite altimetry; waveform retracking; coastal ocean; sea surface height; assessment indicators