diff --git a/04-FFT_DFT_and_Applications/spectrogram.ipynb b/04-FFT_DFT_and_Applications/spectrogram.ipynb deleted file mode 100644 index f63f262..0000000 --- a/04-FFT_DFT_and_Applications/spectrogram.ipynb +++ /dev/null @@ -1,52 +0,0 @@ -{ - "cells": [ - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "# Time-Frequency Analysis\n", - "## Moving window analysis\n", - "One way to analyse the time-varying frequency content of a signal is to\n", - "apply windows in the time domain to the signal and to calculate a Fourier spectrum\n", - "of the windowed part. The window marches along the signal with defined overlap creating\n", - "a series of Fourier spectra associated with the center times of the windows. The resulting amplitude\n", - "spectra are then plotted versus window center time. In more detail:\n", - "\n", - "1. Choose windowing functions: $w(t,t_m)$ with $t_m$ the center of the window.\n", - "2. Multiply windowing function with time series: $f_m(t) = f(t)w(t,t_m)$\n", - "3. Detrend the windowed signal.\n", - "4. Perform a DFT: $F_{km} = \\Delta t\\sum_{n=0}^N f_m(t)\\exp(-2\\pi i \\frac{kn}{N})$\n", - " and calculate the absolute value, $|F_{km}|$.\n", - "5. Plot the resulting matrix: $|F_{km}|$ in the time-frequency plane." - ] - }, - { - "cell_type": "code", - "execution_count": null, - "metadata": {}, - "outputs": [], - "source": [] - } - ], - "metadata": { - "kernelspec": { - "display_name": "Python 3", - "language": "python", - "name": "python3" - }, - "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 3 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython3", - "version": "3.6.7" - } - }, - "nbformat": 4, - "nbformat_minor": 2 -} diff --git a/README.md b/README.md index bb77044..d5e8fc5 100644 --- a/README.md +++ b/README.md @@ -18,4 +18,21 @@ This has been forked from [Seismo Live](http://seismo-live.org). The source code 1. Simple Cross Correlation: Use the cross-correlation to detect and determine the time shift of two test events with one template event. 2. Enhanced Picker: This has been taken from the [ObsPy Tutorial](https://docs.obspy.org/master/tutorial/code_snippets/xcorr_pick_correction.html). ObsPy is licensed under the [LGPL v3.0](https://www.gnu.de/documents/lgpl-3.0.en.html) -3. Ambient Seismic Noise Analysis from [Seismo Live](http://seismo-live.org). The source code is available at https://github.com/krischer/seismo_live (licensed under a ***CC BY-NC-SA 4.0 License***. © 2015-2019 Lion Krischer). \ No newline at end of file +3. Ambient Seismic Noise Analysis from [Seismo Live](http://seismo-live.org). The source code is available at https://github.com/krischer/seismo_live (licensed under a ***CC BY-NC-SA 4.0 License***. © 2015-2019 Lion Krischer). + +### 04 - FFT, DFT and Applications + +Interpolation and Deciamtion of Time Series using the DFT + +### 05 - Spectrogram + +1. Analysing dispersive signals. How to visualize changes in frequency content over time (moving window analysis, mutiple filter technique, instantaneous frequency, continuous wavelet transform, the uncertainty problem). +2. Filtering time series with non spectral filtering method. + +### 06 - Surface Waves + +Analysing phase and group velocity of recorded earthquake signals at one and two seismological stations. + +### 07 - Receiver Functions + +How to get receiver functions from seismograms. \ No newline at end of file