从天体光度测量原理出发推导出光电倍增管、普通CCD和电子倍增CCD在天体光度测量中的信噪比公式,从理论上比较了三种器件在天体光度测量中的性能,并给出了实验结果。结果表明,电子倍增CCD的性能最好;在光辐射度较小的条件下,读出噪声严重地影响了普通CCD的信噪比,光电倍增管的性能较普通CCD的好;而在光辐射度较大的条件下,量子效率成为信噪比的决定因素,普通CCD的性能较光电倍增管的好。最后从误差平方和与信噪比两个方面对理论推导进行了实验验证, 结果表明实验结果和理论计算吻合得很好。

Based on the principle of measurement of celetial body's brightness, the signal-noise ratio (SNR) of photon-multiplier-tube (PMT), common charge-coupled-device (CCD) and electron-multiplying CCD (EMCCD) was deduced, the performance of these three devices had been compared in theory and experiment. The results showed that the performance of EMCCD was the best in all situations. When the radiation was fairly weak, the dominating factor which had an effect on detection ability was readout noise of CCD, so the performance of PMT was better than CCD's. If the radiation is fairly strong, the limits detection ability was quantum efficiency, then the performance of common CCD was better than PMT's. Finally, sum of squared error and signal-noise ratio (SNR) were experimentally validated, it showed that experimental value was consistent with theoretical value.