MIT License

Copyright (c) 2023-2026 Aric Camarata

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

Third-Party Notice: NREL Solar Position Algorithm
--------------------------------------------------

The files src/spa.c and src/spa.h contain the Solar Position Algorithm (SPA)
developed at the National Renewable Energy Laboratory (NREL). These files are
subject to their own license terms, reproduced below from the source:

  Copyright (C) 2008-2011 Alliance for Sustainable Energy, LLC,
  All Rights Reserved

  The Solar Position Algorithm ("Software") is code in development prepared
  by employees of the Alliance for Sustainable Energy, LLC, (hereinafter the
  "Contractor"), under Contract No. DE-AC36-08GO28308 ("Contract") with the
  U.S. Department of Energy (the "DOE"). The United States Government has
  been granted for itself and others acting on its behalf a paid-up, non-
  exclusive, irrevocable, worldwide license in the Software to reproduce,
  prepare derivative works, and perform publicly and display publicly.
  Beginning five (5) years after the date permission to assert copyright is
  obtained from the DOE, and subject to any subsequent five (5) year
  renewals, the United States Government is granted for itself and others
  acting on its behalf a paid-up, non-exclusive, irrevocable, worldwide
  license in the Software to reproduce, prepare derivative works, distribute
  copies to the public, perform publicly and display publicly, and to permit
  others to do so. If the Contractor ceases to make this computer software
  available, it may be obtained from DOE's Office of Scientific and Technical
  Information's Energy Science and Technology Software Center (ESTSC) at
  P.O. Box 1020, Oak Ridge, TN 37831-1020.

  THIS SOFTWARE IS PROVIDED BY THE CONTRACTOR "AS IS" AND ANY EXPRESS OR
  IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  IN NO EVENT SHALL THE CONTRACTOR OR THE U.S. GOVERNMENT BE LIABLE FOR ANY
  SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER,
  INCLUDING BUT NOT LIMITED TO CLAIMS ASSOCIATED WITH THE LOSS OF DATA OR
  PROFITS, WHICH MAY RESULT FROM AN ACTION IN CONTRACT, NEGLIGENCE OR OTHER
  TORTIOUS CLAIM THAT ARISES OUT OF OR IN CONNECTION WITH THE ACCESS, USE OR
  PERFORMANCE OF THIS SOFTWARE.

  Reference: Reda, I., Andreas, A. (2004). "Solar Position Algorithm for
  Solar Radiation Applications." Solar Energy, 76(5), 577-589.

  Original source: https://midcdmz.nrel.gov/spa/