太阳Hα空间望远镜是国际上首次实现全日面Hα单色像(包括Hα线心和线翼3个波段)的空间观测望远镜,对太阳物理研究有着重要的意义。信噪比是定量评价空间望远镜成像质量和工作稳定性的重要指标, 因此信噪比的计算和估计对太阳Hα空间望远镜的研制和使用至关重要。本文从太阳Hα空间望远镜工作原理和能量传递的角度出发, 建立了信噪比计算模型, 推导了信噪比计算公式。在此基础上计算了信噪比以及曝光时间区间, 给出了最佳工作状态下单像元和像元合并情况下曝光时间分别为5 ms和10 ms。实验结果表明, 计算值和测量值误差在1%以内, 由此可以验证该信噪比计算模型的准确性和实用性。

The solar Hα space telescope is the first space observation telescope to realize the full-surface Hα monochromatic image in the world (including the three bands of Hα core and wire wing), which is of great significance for solar physics research. The signal-to-noise ratio (SNR) is an important index for quantitative evaluation of imaging quality and working stability of space telescope, so it is very important to calculate and estimate SNR for the development and use of solar Hα space telescope. The calculation model of the signal-to-noise ratio is established and the formula is derived according to the principle of the solar Hα space telescope and the way of energy transfer. On this basis, the interval of the signal-to-noise ratio and the exposure time is calculated, and the exposure time of the single pixel in the best working condition is 5 ms, and the exposure time of the pixel combination is 10 ms. It has been experimentally verified that the calculated and measured values are within one percent of the error. This can verify the accuracy and practicability of the signal-to-noise ratio calculation model.