The detection of signals hidden in noise is one of the oldest and common problems in astronomy. Various solutions have been proposed in the past such as the parametric approaches based on the least-squares fit of theoretical templates or the non-parametric techniques as the phase-folding method. Most of them, however, are suited only for signals with specific time evolution. For generic signals the spectral approach based on the periodogram is potentially the most effective. In astronomy the main problem in working with the periodogram is that often the sampling of the signals is irregular. This complicates its efficient computation (the fast Fourier transform cannot be directly used) but overall the determination of its statistical characteristics. The Lomb-Scargle periodogram (LSP) provides a solution to this last important issue, but its main drawback is the assumption of a very specific model of the datawhich is not correct for most of the practical applications. These issues are not always considered in literature with theoretical and practical consequences of no easy solution. Moreover, apart from pathological samplings, it is common believe that the LSP and the classical periodogram (CP) usually provide almost identical results. In general, this is true but here it is shown that there are situations where the LSP is less effective than the CP in the detection of signals in noise. There are no compelling reasons, therefore, to use the LSP instead of the CP which is directly connected to the correlation function of the observed signal with the sinusoidal functions at the various frequencies of interest.
Studies in Astronomical Time Series Analysis: The Double Lomb-Scargle Periodogram and Super Resolution
NASA Ames Research Center（NASA 艾姆斯研究中心）；Julius-Maximilians-Universität Würzburg（维尔茨堡大学）；Stanford University（斯坦福大学）；Institut de Física d’Altes Energies (IFAE)（高能物理研究所 (IFAE)）；The Barcelona Institute of Science and Technology (BIST)（巴塞罗那科学技术研究院 (BIST)）
A Multi-instrument Generalized Lomb-Scargle Periodogram Implementation
Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）；Fakultät für Physik und Astronomie, Universität Heidelberg（海德堡大学物理与天文学院）；Department of Astronomy, Universidade de São Paulo（圣保罗大学天文学系）；Space Telescope Science Institute（太空望远镜科学研究所）；William H. Miller III Department of Physics and Astronomy, Johns Hopkins University（约翰斯·霍普金斯大学威廉·H·米勒三世物理与天文系）
本文提出一种多仪器广义 Lomb-Scargle 周期图（GLS）的闭式实现，将其应用于热木星 TOI-481 b 的径向速度数据，能更高显著性地恢复其周期，代码已在 GitHub 开源。
Modern Time-Series and Spectral Methods for Analyzing Solar and Stellar Oscillatory Signals
School of Aerospace, Harbin Institute of Technology, Shenzhen（哈尔滨工业大学（深圳）航天学院）；Faculty of Information Engineering and Automation, Kunming University of Science and Technology（昆明理工大学信息工程与自动化学院）
