Parkes Galactic All-Sky Survey（GASS）的RFI缓解
RFI Mitigation for the Parkes Galactic All-Sky Survey (GASS)
摘要：
GASS是用帕克斯64米射电望远镜观测到的南部天空中银河系原子氢（HI）发射的调查。GASS的通道宽度为1 km/s，灵敏度为60 mK，是对南部天空中银河系HI发射的最灵敏和最准确的调查。我们讨论RFI缓解策略，已应用在数据减少。大多数RFI可以通过使用HI分布的先验信息以及基于中值滤波的统计方法来清除。窄线RFI尖峰在数据处理的第一步期间已被标记。这些线大多数被发现在很长一段时间内是恒定的，这些数据被莱顿/阿根廷/波恩（LAB）调查的内插剖面所取代。通过对0.1度距离内的所有观察结果进行统计学比较，在任何位置搜索剩余RFI。计算线发射的中位数和平均值。在两者之间存在显著偏差的情况下，还检查相关均方根波动是否超过典型分散的3倍。这些数据被中位数取代，这被认为是最少的偏差RFI和其他文物。发现中位数估计量等同于剔除离群值后获得的平均值。
英文摘要：
The GASS is a survey of Galactic atomic hydrogen (HI) emission in the southern sky observed with the Parkes 64-m Radio Telescope. With a sensitivity of 60 mK for a channel width of 1 km/s the GASS is the most sensitive and most accurate survey of the Galactic HI emission in the southern sky. We discuss RFI mitigation strategies that have been applied during the data reduction. Most of the RFI could be cleaned by using prior information on the HI distribution as well as statistical methods based on median filtering. Narrow line RFI spikes have been flagged during the first steps of the data processing. Most of these lines were found to be constant over long periods of time, such data were replaced by interpolating profiles from the Leiden/Argentine/Bonn (LAB) survey. Remaining RFI was searched for at any position by a statistical comparison of all observations within a distance of 0.1 deg. The median and mean of the line emission was calculated. In cases of significant deviations between both it was checked in addition whether the associated rms fluctuations exceeded the typical scatter by a factor of 3. Such data were replaced by the median, which is found to be least biased by RFI and other artifacts. The median estimator was found to be equivalent to the mean, which was obtained after rejecting outliers.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
