一种高光谱相机绝对辐射定标方法

A method of absolute radiation calibration for a hyperspectral camera

随着高光谱相机在特定区域特定波段背景辐射精确测量方面的应用,对高光谱相机辐射定标的精度、分辨率的要求也不断提高。本文通过测量滤波片透过率及积分球出射DN值得到各波段透过的能量占总透过能量的百分比,并结合实际测得的各波段辐亮度,建立其与相机探测器输出的各波段DN值的关系,达到辐射定标的目的。将提高高光谱相机定标分辨率转换为提高测量滤波片透过率的波长分辨率,简化了研究过程。通过定标结果可知,波长在较小范围内变化时,高光谱相机对其增益系数也会发生变化。

With the application of hyperspeetral camera in precise measurement of background radiation in specific areas and bands, the requirements on the accuracy and resolution of the camera＇ s radiation calibration are constantly increased. In this paper, by measuring the filter transmittance and DN value of integrating sphere, the percentage of the energy transmitted fronl each band is obtained. Combined with the percentage and intensity of each wave band, the relation between intensity and the DN value of the camera detector is established, so far,the radiation calibration has been completed. In the paper, to improve calibration resolution of the hyperspeetral camera is converted to improve wavelength measurement resdution of the filter transmittance, which simplifies the research process. The calibration results show that,when the wavelength changes in a small range,the gain coefficient of the hyperspeetral camera changes.