运动补偿下双通道星载高光谱成像仪图像配准

最新一代可见近红外（VNIR）和短波红外（SWIR）双通道星载高光谱成像仪，多采用视场分离器将VNIR和SWIR通道分离为多个子视场，同一时刻各子视场对地成像区域不同，在采用运动补偿技术提高图像信噪比时，各子视场对同一地物的观测角不同，导致图像间失配关系复杂，无法获取同一地物的VNIR-SWIR连续光谱。通过建立运动补偿下的严格成像几何模型，定量分析了双通道图像的畸变和失配规律，进而提出了各子视场分别几何定位再相位相关法配准的方案，并利用东天山区域运动补偿下星载双通道高光谱仿真数据进行验证。结果表明，传统的基于图像的配准方案精度为3.9像元，仍无法得到同一地物像元的VNIR-SWIR光谱曲线，文中方案配准精度提高到0.3像元，VNIR和SWIR重叠波段的反射率光谱重合度误差由41.5%降低到1.2%。

Image registration of the dual-channel spaceborne hyperspectral imager with motion compensation

Latest generation of dual-channel spaceborne hyperspectral imager based on visible near infrared(VNIR)and short wave infrared(SWIR)uses the field slitter to separate VNIR and SWIR channels into several sub-fields,and each sub-field image has different ground area at the same time.When using motion compensation technology to improve signal to noise ratio of the instrument,the observation angles of each sub-field are different,which leads to more complicated mismatch of images and make it impossible to get the continuous VNIR-SWIR spectrum of the ground pixel.The rule of image distortion and dual-channel mismatch quantitatively was analyzed by Rigorous imaging model,and the registration scheme by using geometric orientation of each sub-field separately as well as the phase correlation method was proposed on this basis.Verification based on dual-channel spaceborne hyperspectral simulated data of Dongtianshan under motion compensation was performed.The result shows that registration accuracy of traditional scheme based on correlation of images reaches 3.9 pixel,which means the continuous VNIR-SWIR spectrum of the ground pixel is still unavailable.The registration accuracy of the scheme proposed by this paper reaches 0.3 pixel,and the reflectance spectrum overlap ratio error of the overlapping bands of VNIR and SWIR reduces from 41.5%to 1.2%.