ETM图像大气邻近效应校正

准确地利用所获遥感图像反演地物的反射率,是提高遥感图像后续产品的质量和遥感定最化应用的前提.然而,由于大气对电磁波的散射作用,星载传感器所接收到的被观测目标的电磁辐射信号包含了来自背景地物的贡献,产生了邻近效应,使得所获遥感图像模糊不清,对比度降低,反演的地物反射率精度下降,从而降低了遥感图像后续产品的质量和定量遥感的精度.以ETM图像为实验数据,根据大气辐射传输模型,采用点扩散率函数法进行了ETM图像大气邻近效应校正实验.实验结果表明,经过大气邻近效应校正后,ETM图像的对比度明显增大,图像清晰,可识别细节增加,反演的地物反射率更加准确.

Atmospheric adjacency effect correction of ETM images

It is an important precondition to retrieve the ground surface reflectance exactly for improving the subsequent product of remote sensing images and the quantitative application of remote sensing. However, because the electromagnetic wave is scattered by the atmosphere during its transmission from the ground surface to the sensor, the electromagnetic wave signal of the target received by the sensor contained the signal of the background. The adjacency effect emerges. Because of the adjacency effect, the remote sensing images become blurry, and their contrast reduces. So the ground surface reflectance retrieved from the remote sensing images is also inaccurate. Finally, the quality of subsequent product of remote sensing images and the accuracy of quantitative application of remote sensing might decrease. In the present paper, according to the radiative transfer equation, the atmospheric adjacency effect correction experiment of ETM images was carried out by using the point spread function method. The result of the experiment indicated that the contrast of the corrected ETM images increased, and the ground surface reflectance retrieved from those images was more accurate.