geepers
https://github.com/opera-adt/geepers

Copyright (c) 2025-2026 California Institute of Technology ("Caltech").
U.S. Government sponsorship acknowledged.

Developed at the Jet Propulsion Laboratory, California Institute of
Technology, for the OPERA project. Authors: Marin Govorcin and Scott Staniewicz.

Licensed under the Apache License, Version 2.0 (see LICENSE).

Attribution
-----------
Under Section 4(d) of the Apache License 2.0, any redistribution of this
software, or of a Derivative Work of it, must include a readable copy of
this NOTICE. This applies to any part of the code: whole files, functions,
algorithms ported to another language, and snippets, however they were
copied, including code reproduced or adapted by AI tools (code assistants,
agents, language models).

Wherever code from this repository is reused, keep its copyright and
SPDX header, and cite the source next to the reused code, for example:

    # Adapted from geepers (https://github.com/opera-adt/geepers),
    # Copyright (c) 2025-2026 California Institute of Technology,
    # Apache License 2.0.

For publications, cite the software as given in CITATION.cff.


Third-party data and code
-------------------------
UNR GPS grid
    The gridded GPS time series and velocities shown in the OPERA UNR grid
    viewer, and read by geepers.gps_sources.UnrGridSource, are funded by the
    JPL-led OPERA project. The gridding solution was
    developed by Dr. William C. Hammond at the Nevada Geodetic Laboratory
    (NGL), University of Nevada, Reno (https://geodesy.unr.edu), in
    coordination with the OPERA Algorithm Development Team (ADT), for the
    OPERA Vertical Land Motion (VLM) product.

UNR station time series
    GPS station positions and velocities read by geepers.gps_sources come
    from the Nevada Geodetic Laboratory, University of Nevada, Reno
    (https://geodesy.unr.edu); cite Blewitt, G., Hammond, W. C., &
    Kreemer, C. (2018). Harnessing the GPS data explosion for
    interdisciplinary science. Eos, 99. https://doi.org/10.1029/2018EO104623

MIDAS (src/geepers/midas.py)
    A Python conversion of the MIDAS velocity estimator. Original code:
    https://geodesy.unr.edu/MIDAS_release.tar, Copyright (C) 2015 Geoff
    Blewitt. Cite: Blewitt, G., Kreemer, C., Hammond, W. C., & Gazeaux, J.
    (2016). MIDAS robust trend estimator for accurate GPS station
    velocities without step detection. Journal of Geophysical Research:
    Solid Earth, 121. https://doi.org/10.1002/2015JB012552

Verde (src/geepers/spline.py; methods in masks.py and surface.py)
    The vector spline is adapted from verde.VectorSpline2D, Copyright (c)
    2017 The Verde Developers, BSD 3-Clause License
    (LICENSES/verde-BSD-3-Clause.txt). Uieda, L. (2018). Verde: Processing
    and gridding spatial data using Green's functions. JOSS, 3(29), 957.
    https://doi.org/10.21105/joss.00957

Plate boundaries (viewer)
    PB2002 plate model: Bird, P. (2003). An updated digital model of plate
    boundaries. Geochemistry, Geophysics, Geosystems, 4(3), 1027.
    https://doi.org/10.1029/2001GC000252

Libraries inlined in scripts/browse_unr_grid.html
    MapLibre GL JS (BSD-3-Clause), uPlot (MIT) and hyparquet (MIT), each
    under its own license, kept with its code in that file.
