Treffer: User Manual of GITpy: a Python-based tool for the Generalized Inversion Technique

GITpy is an open-source object-oriented Python software that implements the Generalized Inversion Technique (GIT) to isolate the source, propagation and site contributions to ground shaking in the spectral domain (Fourier Amplitude Spectra, FAS). GITpy includes modules to perform both the non-parametric spectral decomposition and to fit the resulting source spectra and spectral attenuation to standard seismological models. Although the GIT is a well-established approach [Andrews 1986; Castro et al., 1990; Boatwright et al., 1991; Oth et al., 2011; Bindi et al., 2020; Bindi et al., 2023a and 2023b], this tool offers the opportunity to: 1) simplify the attenuation and source modeling process for the user through configuration files or interactive procedures to test different models in a fast way; 2) choose between different levels of attenuation modeling complexity (geometrical spreading and anelastic attenuation); 3) choose between different source spectrum modeling options such as applying a homogeneous or heterogeneous crustal model or selecting the frequency range for the model fitting; 4) calculate apparent source spectra (and relative source parameters) through a specific module using a procedure that allows the input FAS to be corrected for site amplification and non-parametric attenuation obtained from the inversion, and then fit the source spectra as observed at the stations. This is particularly useful for directivity studies. Furthermore, this module can be used independently for a rapid estimation of source parameters in case of a strong event; 5) provide additional source parameters including the radiated energy, the apparent stress and the radiation efficiency together with seismic moment, corner frequency and stress drop. The additional parameters can be estimated for both the best-fit parametric source models and the non-parametric GIT results. Here we present the documentation to help Users in the execution of GITpy. We also provide an example dataset (GITpy_db) to test the GITpy code and Jupyter ...