{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "
\n", "
\n", "
\n", "
Noise
\n", "
Lab: Probabilistic Power Spectral Densities
\n", "
\n", "
\n", "
\n", "\n", "\n", "Seismo-Live: http://seismo-live.org\n", "\n", "##### Authors:\n", "* Tobias Megies ([@megies](https://github.com/megies))\n", "\n", "---" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "%matplotlib inline\n", "import matplotlib.pyplot as plt\n", "plt.style.use(\"bmh\")\n", "plt.rcParams['figure.figsize'] = 10, 6" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ " * read waveform data from file `data/GR.FUR..BHN.D.2015.361` (station `FUR`, [LMU geophysical observatory in Fürstenfeldbruck](https://www.geophysik.uni-muenchen.de/observatory/seismology))\n", " * read corresponding station metadata from file `data/station_FUR.stationxml`\n", " * print info on both waveforms and station metadata" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "from obspy import read, read_inventory\n", "\n", "st = read(\"data/GR.FUR..BHN.D.2015.361\")\n", "inv = read_inventory(\"data/station_FUR.stationxml\")\n", "\n", "print(st)\n", "print(inv)\n", "inv.plot(projection=\"ortho\");" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ " * compute probabilistic power spectral densities using `PPSD` class from obspy.signal, see http://docs.obspy.org/tutorial/code_snippets/probabilistic_power_spectral_density.html (but use the inventory you read from StationXML as metadata)\n", " * plot the processed `PPSD` (`plot()` method attached to `PPSD` object)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "from obspy.signal import PPSD\n", "\n", "tr = st[0]\n", "ppsd = PPSD(stats=tr.stats, metadata=inv)\n", "\n", "ppsd.add(tr)\n", "ppsd.plot()" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Since longer term stacks would need too much waveform data and take way too long to compute, we prepared one year continuous data preprocessed for a single channel of station `FUR` to play with..\n", "\n", " * load long term pre-computed PPSD from file `PPSD_FUR_HHN.npz` using `PPSD`'s `load_npz()` staticmethod (i.e. it is called directly from the class, not an instance object of the class)\n", " * plot the PPSD (default is full time-range, depending on how much data and spread is in the data, adjust `max_percentage` option of `plot()` option) (might take a couple of minutes..!)\n", " * do a cumulative plot (which is good to judge non-exceedance percentage dB thresholds)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "from obspy.signal import PPSD\n", "\n", "ppsd = PPSD.load_npz(\"data/PPSD_FUR_HHN.npz\", allow_pickle=True)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "ppsd.plot(max_percentage=10)\n", "ppsd.plot(cumulative=True)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ " * do different stacks of the data using the [`calculate_histogram()` (see docs!)](http://docs.obspy.org/packages/autogen/obspy.signal.spectral_estimation.PPSD.calculate_histogram.html) method of `PPSD` and visualize them\n", " * compare differences in different frequency bands qualitatively (anthropogenic vs. \"natural\" noise)..\n", " * nighttime stack, daytime stack\n", " * advanced exercise: Use the `callback` option and use some crazy custom callback function in `calculate_histogram()`, e.g. stack together all data from birthdays in your family.. or all German holidays + Sundays in the time span.. or from dates of some bands' concerts on a tour.. etc." ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "ppsd.calculate_histogram(time_of_weekday=[(-1, 0, 2), (-1, 22, 24)])\n", "ppsd.plot(max_percentage=10)\n", "ppsd.calculate_histogram(time_of_weekday=[(-1, 8, 16)])\n", "ppsd.plot(max_percentage=10)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ " * do different stacks of the data using the [`calculate_histogram()` (see docs!)](http://docs.obspy.org/packages/autogen/obspy.signal.spectral_estimation.PPSD.calculate_histogram.html) method of `PPSD` and visualize them\n", " * compare differences in different frequency bands qualitatively (anthropogenic vs. \"natural\" noise)..\n", " * weekdays stack, weekend stack" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "ppsd.calculate_histogram(time_of_weekday=[(1, 0, 24), (2, 0, 24), (3, 0, 24), (4, 0, 24), (5, 0, 24)])\n", "ppsd.plot(max_percentage=10)\n", "ppsd.calculate_histogram(time_of_weekday=[(6, 0, 24), (7, 0, 24)])\n", "ppsd.plot(max_percentage=10)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ " * do different stacks of the data using the [`calculate_histogram()` (see docs!)](http://docs.obspy.org/packages/autogen/obspy.signal.spectral_estimation.PPSD.calculate_histogram.html) method of `PPSD` and visualize them\n", " * compare differences in different frequency bands qualitatively (anthropogenic vs. \"natural\" noise)..\n", " * seasonal stacks (e.g. northern hemisphere autumn vs. spring/summer, ...)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "ppsd.calculate_histogram(month=[10, 11, 12, 1])\n", "ppsd.plot(max_percentage=10)\n", "ppsd.calculate_histogram(month=[4, 5, 6, 7])\n", "ppsd.plot(max_percentage=10)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ " * do different stacks of the data using the [`calculate_histogram()` (see docs!)](http://docs.obspy.org/packages/autogen/obspy.signal.spectral_estimation.PPSD.calculate_histogram.html) method of `PPSD` and visualize them\n", " * compare differences in different frequency bands qualitatively (anthropogenic vs. \"natural\" noise)..\n", " * stacks by specific month\n", " * maybe even combine several of above restrictions.. (e.g. only nighttime on weekends)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [] } ], "metadata": { "jupytext": { "encoding": "# -*- coding: utf-8 -*-" }, "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": "3.12.3" } }, "nbformat": 4, "nbformat_minor": 2 }