OrientPy is a toolbox to help determine seismometer orientation using automated (and manual) processing of earthquake data. These methods are particularly useful for broadband ocean-bottom seismic stations, but are also applicable to broadband land stations or shorter period instruments (depending on the method selected). The code uses the StDb package for querying and building a station database and can be used through command-line scripts. Currently the toolbox includes the following methods:

• DL (Doran and Laske, 2017): Based on Rayleigh-wave polarization at a range of frequencies and for the two fundamental mode Rayleigh wave orbits.

• BNG (Braunmiller, Nabelek and Ghods, 2020): Based on P-wave polarization from regional and teleseismic earthquakes.

Each method can be used independently to produce an estimate of station orientation, in terms of the azimuth of seismic component 1 (or N).

Installation, Usage, API documentation and scripts are described at https://nfsi-canada.github.io/OrientPy/.

Author: Pascal Audet (Developer and Maintainer)

The toolbox DL is heavily based on the software DLOPy written by A. Doran.

All constructive contributions are welcome, e.g. bug reports, discussions or suggestions for new features. You can either open an issue on GitHub or make a pull request with your proposed changes. Before making a pull request, check if there is a corresponding issue opened and reference it in the pull request. If there isn't one, it is recommended to open one with your rationale for the change. New functionality or significant changes to the code that alter its behavior should come with corresponding tests and documentation. If you are new to contributing, you can open a work-in-progress pull request and have it iteratively reviewed.

Examples of straightforward contributions include editing the documentation or adding notebooks/scripts that describe example usage of the code in publications. Suggestions for improvements (speed, accuracy, flexibility, etc.) are also welcome.

• Braunmiller, J., Nabelek, J., and Ghods, A., 2020, Sensor orientation of Iranian broadband seismic stations from P-wave particle motion, Seism. Res. Lett., doi:10.1785/0220200019.

• Doran, A. K., and Laske, G., 2017, Ocean-bottom seismometer instrument orientation via automated Rayleigh-wave arrival-angle measurements, Bull. Seism. Soc. Am., 107, 691-708.