/**
 * @author Theodore Kruczek.
 * @license MIT
 * @copyright (c) 2022-2025 Theodore Kruczek 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
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
import { Minutes, PositionVelocity, Kilometers, Radians } from '../main.js';
import { EpochUTC } from '../time/EpochUTC.js';
import { ClassicalElements } from './ClassicalElements.js';
import { EquinoctialElementsParams } from '../interfaces/EquinoctialElementsParams.js';
/**
 * Equinoctial elements are a set of orbital elements used to describe the
 * orbits of celestial bodies, such as satellites around a planet. They provide
 * an alternative to the traditional Keplerian elements and are especially
 * useful for avoiding singularities and numerical issues in certain types of
 * orbits.
 *
 * Unlike Keplerian elements, equinoctial elements don't suffer from
 * singularities at zero eccentricity (circular orbits) or zero inclination
 * (equatorial orbits). This makes them more reliable for numerical simulations
 * and analytical studies, especially in these edge cases.
 * @see https://faculty.nps.edu/dad/orbital/th0.pdf
 */
export declare class EquinoctialElements {
    epoch: EpochUTC;
    /** The semi-major axis of the orbit in kilometers. */
    a: Kilometers;
    /** The h component of the eccentricity vector. */
    h: number;
    /** The k component of the eccentricity vector. */
    k: number;
    /** The p component of the ascending node vector. */
    p: number;
    /** The q component of the ascending node vector. */
    q: number;
    /** The mean longitude of the orbit in radians. */
    lambda: Radians;
    /** The gravitational parameter of the central body in km³/s². */
    mu: number;
    /** The retrograde factor. 1 for prograde orbits, -1 for retrograde orbits. */
    I: 1 | -1;
    constructor({ epoch, h, k, lambda, a, p, q, mu, I }: EquinoctialElementsParams);
    /**
     * Returns a string representation of the EquinoctialElements object.
     * @returns A string representation of the EquinoctialElements object.
     */
    toString(): string;
    /**
     * Gets the semimajor axis.
     * @returns The semimajor axis in kilometers.
     */
    get semimajorAxis(): Kilometers;
    /**
     * Gets the mean longitude.
     * @returns The mean longitude in radians.
     */
    get meanLongitude(): Radians;
    /**
     * Calculates the mean motion of the celestial object.
     * @returns The mean motion in units of radians per second.
     */
    get meanMotion(): number;
    /**
     * Gets the retrograde factor.
     * @returns The retrograde factor.
     */
    get retrogradeFactor(): number;
    /**
     * Checks if the orbit is prograde.
     * @returns True if the orbit is prograde, false otherwise.
     */
    isPrograde(): boolean;
    /**
     * Checks if the orbit is retrograde.
     * @returns True if the orbit is retrograde, false otherwise.
     */
    isRetrograde(): boolean;
    /**
     * Gets the period of the orbit.
     * @returns The period in minutes.
     */
    get period(): Minutes;
    /**
     * Gets the number of revolutions per day.
     * @returns The number of revolutions per day.
     */
    get revsPerDay(): number;
    /**
     * Converts the equinoctial elements to classical elements.
     * @returns The classical elements.
     */
    toClassicalElements(): ClassicalElements;
    /**
     * Converts the equinoctial elements to position and velocity.
     * @returns The position and velocity in classical elements.
     */
    toPositionVelocity(): PositionVelocity;
}