海洋成像光谱仪信噪比研究

为实现海洋遥感卫星高光谱分辨率及弱目标的探测需求,需要在窄谱段内、低照度下实现高信噪比.通过对成像光谱仪信噪比的推导,建立了成像光谱仪信噪比的评估模型.利用成像光谱仪的光学透过率、光栅的衍射效率、CCD器件的量子效率、CCD暗电流、读出噪声,以及视频噪声等,对海洋水色谱段、中心波长处、典型辐亮度下、5 nm光谱带宽内的系统信噪比进行仿真分析.最后,对系统信噪比进行了测试.测试结果表明:仿真分析正确,此成像光谱仪信噪比可达到60 dB.

Study on Signal-to-Noise Ratio of the Ocean Imaging Spectrometer

To meet the requirements of high spectral resolution and the weak target detection of the ocean remote sensing satellite, the high signal-to-noise ratio (SNR) must be realized in the narrow band and low illumination. By deriving the SNR formula of the imaging spectrometer, the evaluation model is established. By using the optical transmittance, the diffraction efficiency of the grating, the quantum efficiency of CCD, the dark current of CCD, the readout noise and the video noise, the SNR of the system in 5 nm spectra bandwidth is analyzed at ocean color spectral, center wavelength and typical radiance. At last, the system SNR is tested. The results show that the simulation results are correct, the SNR of the imaging spectrometer can achieve to 60 dB.