Cheng, Jen-ChiehJen-ChiehChengDing, Jian-JiunJian-JiunDing2026-03-202026-03-202026-01-0316876172https://www.scopus.com/record/display.uri?eid=2-s2.0-105029164396&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/736488Due to the limitation from the uncertainty principle, the window size consistently affects the resolution of time–frequency distributions. Determining the optimal window size is crucial for time–frequency analysis. In this work, we propose the concept of the reliable window width range along time and frequency axes, which simplifies the process of determining the optimal window size and the search range for adaptive methods. Moreover, in existing work, adaptive time–frequency analyses apply either time- or frequency-varying windows. In this study, we utilize a multitaper technique to integrate time- and frequency-varying windows. The proposed concept of the reliable window width range can be applied to any window-based time–frequency analysis method and enhance post-processing methods in the time–frequency plane. Subsequently, together with the reliable window width range, we propose the multitaper adaptive time–frequency windowed synchroextracting transform. It can estimate the optimal window size for time and frequency axes simultaneously and achieve a more energy-concentrated time–frequency analysis result.trueAdaptive time–frequency analysisMultitaperSynchroextracting transformThe reliable range of the window widthWindow sizejournal article10.1186/s13634-025-01287-82-s2.0-105029164396