Month: September 2025

Fast streaming local time-frequency transform

September 11, 2025 Examples No comments

A new paper is added to the collection of reproducible documents: Fast streaming local time-frequency transform for nonstationary seismic data processing 

Schematic illustration of the proposed SLTFT

The CPU time comparison among the time-frequency analysis methods. Orange line: STFT; blue dash line: SLTFT; red dot line: streaming attributes; green dash-dot line: LTF decomposition. The convergence speed affects the CPU time of the LTF decomposition, resulting in a non-smooth curve

Time-frequency analysis serves as a useful approach to solve different complex problems in seismic data processing. From a practical standpoint, the majority of time-frequency transform techniques frequently grapple with the trade-off between time and frequency localization adaptability, flexibility in sampling time and frequency, and the pursuit of computational efficiency. To address this, we tailor the streaming computation to implement a fast time-frequency transform, namely the streaming local time-frequency transform (SLTFT), which can significantly decrease the computational cost of adaptive time-frequency analysis. We add a localization scalar to the proceeding streaming algorithm to circumvent the need for taper functions, which provides rapid forward and inverse transforms and applicability in various scenarios. We demonstrate the adaptive time-frequency characteristics of the proposed method, which offers a nonstationary time-frequency representation with variable time-frequency localization. Numerical tests indicate that the proposed SLTFT is a more balanced method compared to previous time-frequency adaptive transforms. It proves suitable for a range of practical applications in nonstationary seismic data processing, including ground-roll attenuation, inverse-Q filtering, and multicomponent data registration.

madagascar-4.2

September 9, 2025 Celebration No comments

The major version of Madagascar, stable version 4.2, has been released. The new version includes new reproducible papers and other enhancements.

According to the SourceForge statistics, the previous stable distribution has been downloaded about 6,000 times. The top country (with 38% of all downloads) was China, followed by the USA, Brazil, Germany, and India.

The total cumulative number of downloads for the stable version of Madagascar has exceeded 70 thousand. The current development version continues to be available through Github.