The spaceborne Global Navigation Satellite System-Reflectometry (GNSS-R) delay-Doppler map (DDM) data collected over ocean carry typical feature information about the ocean surface, which may be covered by open water, mixed water/ice, complete ice, etc. A new method based on Doppler spread analysis is proposed to remotely sense sea ice using the spaceborne GNSS-R data collected over the Northern and Southern Hemispheres. In order to extract useful information from DDM, three delay waveforms are defined and utilized. The delay waveform without Doppler shift is defined as central delay waveform (CDW), while the integration of delay waveforms of 20 different Doppler shift values is defined as integrated delay waveform (IDW). The differential waveform between normalized CDW (NCDW) and normalized IDW (NIDW) is defined as differential delay waveform (DDW), which is a new observable used to describe the difference between NCDW and NIDW, which have different Doppler spread characteristics. The difference is mainly caused by the roughness of reflected surface. First, a new data quality control method is proposed based on the standard deviation and root-mean-square error (RMSE) of the first 48 bins of DDW. Then, several different observables derived from NCDW, NIDW, and DDW are applied to distinguish sea ice from water based on their probability density function. Through validating against sea ice edge data from the Ocean and Sea Ice Satellite Application Facility, the trailing edge waveform summation of DDW achieves the best results, and its probabilities of successful detection are 98.22% and 96.65%, respectively, in the Northern and Southern Hemispheres.

中文翻译：

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基于星载GNSS-R数据多普勒扩展分析的海冰感知

在海洋上收集的星载全球导航卫星系统反射计 (GNSS-R) 延迟多普勒图 (DDM) 数据携带有关海面的典型特征信息，可能被开阔水域、混合水/冰、完全冰等覆盖提出了一种基于多普勒扩展分析的新方法，利用在北半球和南半球收集的星载 GNSS-R 数据遥感海冰。为了从 DDM 中提取有用的信息，定义并使用了三个延迟波形。没有多普勒频移的延迟波形定义为中心延迟波形（CDW），而20个不同多普勒频移值的延迟波形的积分定义为积分延迟波形（IDW）。归一化CDW（NCDW）和归一化IDW（NIDW）之间的差分波形被定义为差分延迟波形（DDW），它是一种新的观测值，用于描述具有不同多普勒扩展特性的NCDW和NIDW之间的差异。差异主要是由反射面的粗糙度引起的。首先，基于DDW的前48个bin的标准偏差和均方根误差（RMSE）提出了一种新的数据质量控制方法。然后，从 NCDW、NIDW 和 DDW 派生的几个不同的观测值被用于根据概率密度函数区分海冰和水。通过对来自海洋和海冰卫星应用设施的海冰边缘数据进行验证，DDW的后沿波形求和达到了最佳效果，