Tang Fei, Xu Han-Qiu
Guang Pu Xue Yu Guang Pu Fen Xi. 2014 Apr;34(4):1075-80.
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.
不透水表面的提取是过去十年遥感领域的一个热门话题。然而，关于从高光谱图像中提取不透水表面以及高光谱图像与多光谱图像在提取不透水表面性能方面的比较研究却鲜有报道。因此，本文聚焦于高光谱（EO-1 Hyperion）和多光谱（Landsat TM/ETM+）图像的特征，并基于Hyperion和TM/ETM+数据提取的不透水表面信息进行了对比的补充研究。对于Hyperion图像的多达242个波段，进一步开展研究，采用逐步判别分析选择用于不透水表面提取的特征波段。结果，选择了11个特征波段，从而构成了一幅名为Hyperion'的新图像。利用新的Hyperion'图像研究这幅波段减少的图像在提取不透水表面时是否能获得更高的精度。从中国的福州、广州和杭州选取了三个测试区域，使用的传感器具有日期一致或近乎一致的图像对。采用线性光谱混合分析（LSMA）提取不透水表面，并对结果的精度进行评估。比较结果表明，Hyperion图像的精度高于TM/ETM+，由所选11个特征波段构成的Hyperion'图像精度最高。Hyperion在光谱和辐射分辨率方面优于TM/ETM+，被认为是精度更高的主要因素。Hyperion图像的高光谱和辐射分辨率使传感器在区分地面物体细微光谱变化方面具有更高的灵敏度。而11波段Hyperion'图像实现的最高精度归因于图像波段维度的显著减少以及波段冗余的降低。
