稀疏轨道条件下SAR几何校正轨道拟合策略

针对SAR影像头文件中提供的轨道矢量分布较为稀疏时，使用低阶多项式拟合轨道参数会存在较大误差，从而导致基于距离-多普勒模型的星载SAR影像几何校正精度较差的问题，提出了一种稀疏轨道条件下实用的轨道拟合策略。通过对轨道拟合误差进行分析，综合考虑距离-多普勒模型的解算与现有几何校正资源，选择使用高阶插值方法生成卫星成像时刻处足够的加密点轨道状态矢量，再对局部的轨道进行二阶多项式拟合，利用拟合的轨道模型系数进行几何校正。利用实测GPS点数据进行了SAR几何校正精度验证，结果表明该策略能够明显改善ALOS2 PALSAR影像几何校正精度，证明了该方法的有效性和良好的适用性。

Resolution Merge Method of CBERS-02B HR and CCD Data

CBERS-02B can acquire different spatial resolution and multi-specual data which improves its application ability greatly.However,the spatial resolutions of HR and CCD aredifferent so largdy that resolution merge often cause some problem such as spectral distortion.In this paper,we proposed a two step resolution merge method of HR and OCD data of CBERS-02B.The result shows that the method is effective and can improve the final result of resolution merge compared with the normal method.