WorldView卫星16波段影像光谱特征分类

传统的高分辨率遥感卫星光谱分辨率较低，WorldView卫星在8个可见光G近红外多光谱波段的基础上，新增加的８个短波红外(short wave infrared,SWIR)影像，有助于提高影像提取地物信息能力。分析了WorldView卫星的16波段影像上各种地物的光谱特征和分类性能，提出了新的植被指数、水体指数和建成区指数。实验表明，相比于8波段影像,使用16波段影像分类能够显著提高各类地物特别是裸地、建筑物和道路的分类精度，总体精度提高约5.5％。基于16波段设计的新地物特征指数能更好地避免干扰地物，通过简单阈值提取地物，取得较高的提取精度。

A Comparison of the Algorithms of Land Surface Temperature Retrieval from Landsat TM Thermal Band

The atmospheric parameters the downwelling atmospheric radiance （L^atm↓）, the upwelling atmospheric radiance （Lλ^atm↑）, and the total atmospheric transmissivity （τ） between the surface and the sensor, can be approximately estimated by the mono-window algorithm and the generalized single-channel method. The differences between three atmospheric parameters in two algorithms were analyzed and simulated. The results indicated that the generalized single-channel method overestimated L^atm↓ and Lλ^atm↑and underestimated r when the total atmospheric water vapor content （ω） is high. This made the former retrieve higher land surface temperature except that both the total atmospheric water vapor content （ω） and the mean atmospheric temperature are low. Further analysis shows that the generalized single-channel method is not really generally prevalent and that it is not suitable for the circumstances of high total atmospheric water vapor content （ω） and/or high mean atmospheric temperature.