机载综合孔径辐射计图像和光学图像融合及评价

Airborne Synthetic Aperture Radiometer image and Optical Data Fusion and Evaluation

微波辐射计图像可以很直观的反映地表亮温,但其分辨率不高且图像地物的几何外形不明显等缺点给研究带来诸多不便。现有一些光学图像与之相比,具有分辨率高,几何外形更清晰等优点。如何有效利用光学图像的信息来研究辐射计图像是一件有意义的课题。采用IHS方法、PCA方法、小波方法对机载综合孔径微波辐射计图像和Landsat ETM+图像进行融合。从对实验结果定量和定性的分析表明小波融合方法更具潜力。融合结果中可以看出在多光谱图像中表达相似的地物,可以很快的在图像中分辨出来。结果图像基本上保持了辐射计图像的辐射特性,并且融合了光学图像的不同地物的光谱信息,为在辐射计图像上对大区域地物的解译和分析带来方便。

Microwave radiometer image contains information of ground brightness temperature. For its low resolution and unclear object＇s shape, it is not convenient to be studied. Something like SAR, synthetic aperture microwave radiometer also has the characteristics that it can acquire images during day and night and with all weather conditions. Moreover, it has the ability to “penetrate” surface soil or vegetation under lower frequency region. Contrast to the radiometer image, the optical images have higher resolution and contain different information. To integrate some features of these two kinds of images, some transform schemes, such as intensity-hue-saturation （IHS）, principal component analysis （PCA） and wavelet transform （WT）, were applied to merge the airborne synthetic aperture microwave radiometer and ETM＋ images. The experiments show that the wavelet based transform method not only can preserve the spectral information of ETM＋ image well, but also can preserve the texture information from radiometer image. In conclusion, the WT approach has the best potential among those three methods.