中国科学院云南天文台机构知识库

大气背景辐射强弱决定了红外望远镜系统极限灵敏度,直接影响系统设计,背景辐射也是反映天文台站观测性能优劣与否的一项重要指标。实测了国内的阿里天文台、德令哈观测站、怀柔观测站等几个典型天文台站大气红外背景辐射,尤其是获得了阿里天文台大气红外背景辐射的一手资料。实测结果表明:阿里天文台大气红外背景辐射的强弱以及辐亮度均值的昼夜变化在几个台站中均最小,其最大辐亮度均值为1.30×10-6W·cm-2·sr-1,辐亮度均值的最大昼夜变化仅为18%,其红外背景辐射限最优;其次是德令哈观测站。将扫天实测辐亮度与MODTRAN模拟辐亮度进行对比,发现对于国内如阿里等青藏高原高海拔地区无论是标准大气模式还是实际大气模式其模拟结果与实测间皆存在较大差异。 

The intensity of background radiation directly determines the sensitivity limit of the infrared telescope system and directly affects the system design. Background radiation is also an important index to reflect the astronomical observing conditions and performance of observatory stations. The atmospheric infrared background radiation of Ali, Delingha Observatory and Huairou Observatory astronomical observatories were measured, particularly the first-hand data of atmospheric infrared background radiation were obtained for the Ali astronomical observatories. The measured results show that the atmospheric infrared background radiation intensity and the diurnal variation of the radiance on the Ali astronomical observatories are the smallest among the three stations, and the average values of the highest radiance is 1.30 ×10 -6 W·cm -2·sr -1. The maximum diurnal variation of Ali's radiance mean value is only 18%. Therefore, the lowest infrared background radiation limits is Ali astronomical observatories. The second is Delingha Observatory. Finally, the measured radiance in sky sweeping was compared with the MODTRAN software simulated radiance. It is found that there is quite a difference between the simulation results and the actual measurement in the high altitude areas of the Qinghai-Tibet Plateau, whether it is the standard atmospheric mode or the actual atmospheric mode.