Quantum Time Series Analysis: Drift, Noise Spectroscopy and Calibration Forecasting R package qtsa version 0.1.1 Tools for exploratory statistical analysis of quantum-hardware calibration time series. The package provides simulators for random telegraph noise (RTN), power-law noise, and Ornstein-Uhlenbeck dephasing; Welch and sine-multitaper power spectral density estimators; a lightweight two-state hidden Markov model for switching signals; cumulative sum (CUSUM) and binary-segmentation diagnostics for calibration drift; residual-quantile interval forecasts; and filter-function calculations for illustrative coherence curves. The package includes a reproducible generator of simulated superconducting-qubit calibration records; it does not retrieve authenticated live provider data. Methodological background is provided by Welch (1967) <doi:10.1109/TAU.1967.1161901>, Thomson (1982) <doi:10.1109/PROC.1982.12433>, Rabiner (1989) <doi:10.1109/5.18626>, Page (1954) <doi:10.1093/biomet/41.1-2.100>, Paladino et al. (2014) <doi:10.1103/RevModPhys.86.361>, and Cywinski et al. (2008) <doi:10.1103/PhysRevB.77.174509>. Software Depends: R (>= 4.1.0) Imports: stats, graphics, utils Leila Marvian Mashhad <leila.marveian@gmail.com> Comprehensive R Archive Network (CRAN) Leila Marvian Mashhad [aut, cre] MIT + file LICENSE (https://CRAN.R-project.org/package=qtsa/LICENSE) 2026-08-06 application/tgz https://CRAN.R-project.org/package=qtsa doi:10.32614/CRAN.package.qtsa