太阳参考光谱是星上辐射定标和波长定标的基准。 太阳活动周期内, 太阳辐照度光谱幅值存在周期性波动, 紫外波段光谱幅值变化达10%以上, 相对于3%的星上绝对定标需求, 太阳的时变特性不可忽略。 针对不同分辨率和采样率的太阳参考光谱, 首先研究了插值间隔和卷积间隔对计算MgII参数的数值影响, 通过分析比较后选择合适的插值、 卷积间隔, 并基于Climate和SORCE的MgII参数时间序列完成太阳周期性变化建模。 然后选择2003年8月21日至2012年4月15日期间80组数据, 每组包含2个不同日期的不同波长的辐照度光谱幅值和MgII值, 针对该80组数据使用一阶拟合取代比值方法计算得到转换因子, 将不同日期的太阳参考光谱幅值修正到同一日期并与实际观测真值比较; 结果表明了一阶拟合与比值方法相比有着更高的反演精度及预测精度。 最后, 基于一阶拟合转换因子和MgII参数时间序列对现有光谱进行时间和格式归一化, 通过分波段筛除偏离较大光谱数据的方法构建了2008年6月25日, 分辨率为1 nm、 采样率为0.1 nm的太阳参考光谱。 原有的12条光谱经过筛除后, 留下全波段均位于中位的光谱6条, 所构建的光谱同筛选出的6条光谱平均值相比, 绝对误差在0.982%以内。 所构建的光谱可以通过MgII参数时间序列和转换因子计算得到任意日期下的光谱。 针对该参考光谱利用KNMI高光谱进行分辨率和采样率提升, 最终基于我国计划发射的风云三号紫外高光谱臭氧探测仪（OMS）在轨观测和星上定标需求, 构建得到了波长范围250～500 nm, 分辨率0.1 nm, 采样率0.01 nm的太阳参考光谱。

The solar reference spectrum is the basis for radiometric calibration and wavelength calibration in the field of on-board calibration. During the solar cycle, the amplitude of the solar irradiance spectrum fluctuates periodically, changing by more than 10% in the ultraviolet band. However, the on-board absolute calibration requirement is 3%. Temporal variation characteristics of the sun cannot be ignored. First of all, we studied the influence of calculation of MgII when given spectra, which are based on interpolation and convolution intervals, with different resolutions and sampling. After selecting appropriate interpolation and convolution interval, we model the periodic variation of the solar-based on the MgII of Climate spectrum and SORCE spectrum. Secondly, we select 80 sets (there are two dates for every set) of amplitude variation of MgII and irradiance at a different wavelength from August 21, 2003, to April 15, 2012. By first order fitting instead of ratio method, the first order fitting method decreases error from 1.167% to 0.125% for Climate spectrum, from 1.057% to 0.558% for SORCE spectrum, when compared to true irradiance data from August 21, 2003, to April 15, 2012. The results show that the first-order fitting method has higher inversion precision and prediction accuracy than the ratio method. Finally, based on time series of MgII we fulfil normalization of time and format of the spectrum. By eliminating large deviated data over the different spectrum, we got a solar reference spectrum with the resolution of 1 nm and sampling of 0.1 nm on June 25, 2008. In addition, the spectrum has an absolute error of 0.982% compared to the average of six spectra without eliminating deviated data in all wavelength. The spectrum can also be converted to any day using solar cycle activity model based on MgII and conversion factor. By promotion of resolution and sampling for this reference spectrum based on KNMI hyperspectral, as a result, we get the solar reference spectrum with the spectrum range of 250~500 nm, resolution of 0.1 nm and sampling of 0.01 nm, which can provide reference spectrum for on-orbit observation and on-board calibration of China’s FY-3 ultraviolet hyperspectral ozone detector (OMS).