基于SIR-C数据的SAR极化特征参数区分海冰与海水的能力评价

利用1994年10月南极区域的6景SIR-C影像,评估了L波段和C波段下13种主要的SAR极化特征参数区分海冰、海水信息的能力。结果表明:L波段下有6种参数能较好地区分海冰和海水,它们是:散射熵、交叉极化比HV/VV、同极化比VV/HH、同极化相关系数ρHH-VV、HV极化后向散射系数、Alpha角;另外,HH极化后向散射系数、交叉极化比HV/HH具有一定的区分海冰和海水的能力;其余5种难以区分海冰和海水。C波段下有4种参数能较好地区分海冰和海水,他们是:散射熵、同极化相关系数ρHH-VV、HV极化后向散射系数、同极化比VV/HH;HH极化后向散射系数、交叉极化比HV/VV、Alpha角和VV极化后向散射系数这4种参数具有一定的区分海冰和海水的能力;其余5种难以区分海冰和海水。且总体来看,L波段区分海冰和海水的能力好于C波段。这为海冰探测的研究提供了有用的参考。

THE CAPACITY EVALUATION THAT USE POLARIZATION CHARACTERISTIC PARAMETERS OF SAR TO DISTINGUISH SEA ICE AND SEAWATER WITH SIR-C DATA

The sea ice identification capability of 13 kinds of polarization characteristic parameters on L-Band and C-Band using SIR-C images in Antarctica are assessed. Six parameters best distinguish sea ice from seawater on L-band: entropy, cross polarization ratio HV/VV, polarization ratio VV/HH, polarization correlation coefficient ρHH-VV, HV polarization backscatter coefficient, and Alpha angle. Additionally, HH polarization backscatter coefficient and cross-polarization ratio HV/HH differentiate sea ice from seawater, whereas other parameters experience difficulty doing so. Four parameters best distinguish sea ice and seawater on C-band: entropy, polarization correlation coefficient ρHH-VV, HV polarization backscatter coefficient, and polarization ratio VV/HH; HH polarization backscatter coefficient, cross-polarization ratio HV/VV, Alpha angle and VV polarization backscattering coefficient can also differentiate sea ice and seawater, but the remaining five parameters have difficulty doing so. Overall, L-band capabilities distinguish sea ice from seawater better than C-band. This provides a useful reference for sea ice detection studies.