极化SAR遥感中森林特征探测

为了利用微波遥感数据对森林植被地区进行分类检测,寻找一种新的敏感于树木高度、种群数量和植被疏密程度等森林特征的遥感参量,该文利用中国天山地区SIR-C/X-SARL波段全极化干涉数据,对极化散射矩阵总功率、极化熵、相似性参数和极化干涉最优相关系数等极化和干涉合成孔径雷达(SAR)遥感参数进行了分析,并将这些参数进行加权组合,利用特征值分析方法求取最优加权系数,从而提出两种对森林特征敏感的参数组合表达式。在比较上述组合表达式图与同地区极化遥感总功率图之后,发现该组合表达式图中,森林地区较其他地区获得明显加强。这表明提出的组合表达式对森林地区的检测和监测具有良好的效果。

A review of underlying topography estimation over forest areas by In SAR: Theory, advances, challenges and perspectives

The paramount importance and multi-purpose applications of underlying topography over forest areas have gained widespread recognition over recent decades, bringing about a variety of experimental studies on accurate underlying topography mapping. The highly spatial and temporal dynamics of forest scenarios makes traditional measuring techniques difficult to construct the precise underlying topography surface. Microwave remote sensing has been demonstrated as a promising technique to retrieve the underlying topography over large areas within a limited period, including synthetic aperture radar interferometry(InSAR), polarimetric InSAR(PolInSAR) and tomographic SAR(TomoSAR). In this paper, firstly, the main principle of digital elevation model(DEM) generation by InSAR and SAR data acquisition over forest area are introduced. Following that, several methods of underlying topography extraction based on InSAR, PolInSAR, and TomoSAR are introduced and analyzed, as well as their applications and performance are discussed afterwards. Finally, four aspects of challenge are highlighted, including SAR data acquisition, error compensation and correction, scattering model reconstruction and solution strategy of multi-source data, which needs to be further addressed for robust underlying topography estimation.

一种基于深度学习的舰船目标融合识别算法

低分辨率SAR(合成孔径雷达)卫星遥感图像具有大幅宽特点,是广域海上目标搜索的重要手段,但相较于高分辨率遥感图像,可用于目标识别的特征较少,导致识别性能有待提高。论文探索并设计了一种基于深度学习的低分辨率多极化SAR卫星遥感图像舰船目标融合识别的算法。首先,以多极化SAR图像为输入,利用改进的VGG16网络提取图像特征得到各极化通道的分类结果,同时自动学习各极化通道的权重,然后,对分类结果进行决策级加权融合;最后,利用公开的OpenSARShip数据集进行实验验证,结果表明,与单极化SAR图像舰船目标识别以及其他融合识别方法相比,该算法一定程度上提升了舰船目标识别效果。