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- /*
- * Copyright (C) 2021 Christopher J. Howard
- *
- * This file is part of Antkeeper source code.
- *
- * Antkeeper source code is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * Antkeeper source code is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
- */
-
- #ifndef ANTKEEPER_PHYSICS_TIME_UT1_HPP
- #define ANTKEEPER_PHYSICS_TIME_UT1_HPP
-
- #include "math/constants.hpp"
-
- namespace physics {
- namespace time {
-
- /// Functions which operate on UT1 universal time.
- namespace ut1 {
-
- /**
- * Calculates the Earth Rotation Angle (ERA) at a given UT1 date.
- *
- * @param t J2000 UT1 date.
- * @return ERA at the given date, in radians.
- */
- template <class T>
- T era(T t);
-
- template <class T>
- T era(T t)
- {
- return math::two_pi<T> * (T(0.7790572732640) + T(1.00273781191135448) * t);
- }
-
- } // namespace ut1
-
- } // namespace time
- } // namespace physics
-
- #endif // ANTKEEPER_PHYSICS_TIME_UT1_HPP
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