高光谱与多光谱遥感影像反演地表不透水面的对比——以Hyperion和TM/ETM+为例

不透水面遥感信息的反演是近十年来遥感领域的一个热门课题，但是利用高光谱影像反演不透水面信息的研究较少，高光谱和多光谱影像反演不透水面的对比研究也少有报道。重点研究了高光谱EO-1 Hyperion和多光谱Landsat TM/ETM+数据在反演不透水面信息方面的特点，首先在福州、广州和杭州选取了三个实验区，利用线性光谱混合分析模型反演Hyperion和TM/ETM+影像的不透水面信息。对于多达242个波段的Hyperion影像，进一步利用判别分析从中选取了11个特征波段构成新的Hyperion’影像，以考察是否可用缩减波段的方法来取得较好的反演效果。结果表明，Hyperion高光谱影像反演不透水面的能力优于多光谱影像TM/ETM+，而利用特征波段构成的Hyperion’的反演精度最高，这主要得益于Hyperion具有更高的光谱分辨率和辐射分辨率，使其可以更有效地区别不同地物在光谱特征和辐射特征上的微细变化，从而可以更好地区分不同地物。而由特征波段构成的Hyperion’影像由于大幅减少了高光谱影像波段的冗余度，所以获得了更高的反演精度。

Comparison of Performances in Retrieving Impervious Surface between Hyperspectral (Hyperion) and Multispectral (TM/ETM+) Images

The retrieval of impervious surface is a hot topic in the remote sensing field in the past decade. Nevertheless, studies on retrieving impervious surface from hyperspectral image and the comparison of the performances in retrieving impervious surface between hyperspectral and multispectral images are rarely reported. Therefore, The present paper focuses on the characteristics of hyperspectral (EO-1 Hyperion) and multispectral (Landsat TM/ETM+) images and implements a complementary study on the comparison based on the retrieved impervious surface information between Hyperion and TM/ETM+ data. For up to 242 bands of Hyperion image, a further study was carried out to select feature bands for impervious surface retrieving using stepwise discriminant analysis. As a result, 11 feature bands were selected and a new image named Hyperion’ was thus composed. The new Hyperion’ image was used to investigate whether this band-reduced image could obtain higher accuracy in retrieving impervious surface. The three test regions were selected from Fuzhou, Guangzhou and Hangzhou of China, with date-coincident or nearly coincident image pairs of the used sensors. The linear spectral mixture analysis (LSMA) was employed to retrieve impervious surface and the results were accessed for their accuracy. The comparison shows that the Hyperion image has higher accuracy than TM/ETM+, and the Hyperion’ composed of the selected 11 feature bands has the highest accuracy. The advantages of Hyperion in spectral and radiometric resolutions over TM/ETM+ are believed to be the main factors contributing to the higher accuracy. The high spectral and radiometric resolutions of Hyperion image allow the sensor to have higher sensitivity in distinguishing subtle spectral changes of ground objects. While, the highest accuracy the 11-band Hyperion’ image achieved is owing to the significant reduction of the band dimension of the image and thus the band redundancy.