peak-particle-velocity

Raspberry Shake Peak Particle Velocity (PPV) calculation script

Coded by Giuseppe Petricca (@gmrpetricca)

This script will read data from a 3D unit on the Raspberry Shake AM network (or in stand-alone mode) and convert the output displacement (in mm) into Ground Vibration measurement (PPV - in mm/s).

The source for the conversion formula is here.

Required software and packages:

• Python 3
• Jupyter
• Obspy
• Matplotlib
• Numpy

For the offline version two more packages are needed:

• datetime
• paramiko

Installation via Anaconda (online version):

# install the environment with the correct software:
conda create -n ppvmotion python=3 jupyter jupyterlab matplotlib obspy numpy
# activate the environment
conda activate ppvmotion
# navigate to the folder where you have the Python code via command prompt
cd -local address of the Python folder-
# start Jupyter Lab
jupyter lab

Installation via Anaconda (offline version):
```bash
# install the environment with the correct software:
conda create -n ppvmotion python=3 jupyter jupyterlab matplotlib obspy numpy paramiko
# activate the environment
conda activate ppvmotion
# navigate to the folder where you have the Python code via command prompt
cd -local address of the Python folder-
# start Jupyter Lab
jupyter lab

Once this is done, it is possible to open one of the two .ipynb files in the repository:

• PPVmotion-online.ipynb for when the station is connected to the network
• PPVmotion-offline.ipynb for when the station is in stand-alone mode

Some data are provided in the offline folder for testing purposes. Please keep the folder structure as it is.

The station.xml provided file is for a RS3D V5 Shake unit. Different Shakes will reqiuire different files, they can be found here.

The file is commented throughout the various steps, however, this is a brief guide to use it:

1. Insert a valid Raspberry Shake 3D (RS3D) unit code
2. Insert a valid start and end time references for the script to work. The format is "YYYY-MM-DDThh:mm:ss.ddd"
3. If needed, modify the values for the filtering process (the default is a bandpass filter between 0.7 Hz and 2.0 Hz)
4. The filter can also be removed by commenting out (with #) line 48 of the online script or line 94 of the offline script st.filter("bandpass", freqmin=f1, freqmax=f2, corners=cor)

Done! Executing the script will create and save a plot which whill show the Peak Particle Velocity (in mm/s) for each channel (EHZ, EHN, EHE) of the selected RS3D unit.

-- Troubleshooting: If required, the datetime package can be installed from within the environment with pip install DateTime.