import type { OrbitClass } from "./kinds.ts";
/**
 * The height of the geostationary orbit above the equator, in kilometres: the radius of a circular orbit that goes round once a sidereal day (42,164 km) less the equatorial radius (6,378 km). The heights in this module are above the mean Earth radius of 6,371 km, which differs by 7 km, well inside the 1,500 km band.
 *
 * @example
 * ```ts
 * import { GEO_ALTITUDE_KM } from "@johnmorrisdotca/chikyu-earth/catalogue";
 *
 * console.log(GEO_ALTITUDE_KM);
 * ```
 */
export declare const GEO_ALTITUDE_KM = 35786;
/**
 * The size and shape of an orbit.
 *
 * @example
 * ```ts
 * import type { OrbitShape } from "@johnmorrisdotca/chikyu-earth/catalogue";
 *
 * const show = (shape: OrbitShape): string => `${shape.perigeeKm.toFixed(0)} to ${shape.apogeeKm.toFixed(0)} km`;
 * console.log(typeof show);
 * ```
 */
export interface OrbitShape {
    /** Half the longest width of the ellipse, kilometres from the Earth's centre. */
    semiMajorKm: number;
    /** One revolution, minutes. */
    periodMinutes: number;
    /** Height of the lowest point above the mean Earth radius (6371 km), kilometres. */
    perigeeKm: number;
    /** Height of the highest point, kilometres. */
    apogeeKm: number;
    eccentricity: number;
}
/**
 * The shape of an orbit from the two numbers every element set has: its mean motion (revolutions a day) by Kepler's third law, and its eccentricity. Heights are above the mean Earth radius (6371 km), the same as the satellites' own readout.
 *
 * @param meanMotion - Revolutions a day, above 0.
 * @param eccentricity - 0 up to (not including) 1.
 * @returns The shape; `null` for a mean motion or an eccentricity that is not an orbit.
 *
 * @example
 * ```ts
 * import { orbitShape } from "@johnmorrisdotca/chikyu-earth/catalogue";
 *
 * const iss = orbitShape(15.4915, 0.0007139);
 * console.log(iss && Math.round(iss.perigeeKm), iss && Math.round(iss.periodMinutes), orbitShape(0, 0));
 * ```
 */
export declare function orbitShape(meanMotion: number, eccentricity: number): OrbitShape | null;
/**
 * The numbers behind the classes: the highest point a low orbit may have (2,000 km), the eccentricity from which an orbit is highly elliptical (0.25), and how far from 35,786 km the lowest and highest points of a geostationary orbit may be (1,500 km).
 *
 * @example
 * ```ts
 * import { CLASS_LIMITS } from "@johnmorrisdotca/chikyu-earth/catalogue";
 *
 * console.log(CLASS_LIMITS.leoApogeeKm, CLASS_LIMITS.heoEccentricity, CLASS_LIMITS.geoBandKm);
 * ```
 */
export declare const CLASS_LIMITS: {
    readonly leoApogeeKm: 2000;
    readonly heoEccentricity: 0.25;
    readonly geoBandKm: 1500;
};
/**
 * The class an orbit falls in. `heo` when the eccentricity is 0.25 or more; otherwise `leo` when the highest point is under 2,000 km, `geo` when both points are within 1,500 km of 35,786 km, `meo` when the lowest point is 2,000 km or more and the highest is under that band, and `other` for what is left (above the geostationary belt, or between the classes).
 *
 * @param shape - The orbit's shape, from `orbitShape`.
 * @returns The class.
 *
 * @example
 * ```ts
 * import { orbitClass, orbitShape } from "@johnmorrisdotca/chikyu-earth/catalogue";
 *
 * const of = (n: number, e: number): string => orbitClass(orbitShape(n, e)!);
 * console.log(of(15.49, 0.0007), of(2.0056, 0.0001), of(1.0027, 0.0002), of(2.0, 0.72), of(0.9, 0.001));
 * ```
 */
export declare function orbitClass(shape: OrbitShape): OrbitClass;
/**
 * The class of an orbit straight from the two numbers every element set has, its mean motion (revolutions a day) and its eccentricity; `null` when they are not an orbit.
 *
 * @param meanMotion - Revolutions a day, above 0.
 * @param eccentricity - 0 up to (not including) 1.
 * @returns The class, or `null`.
 *
 * @example
 * ```ts
 * import { classOfElements } from "@johnmorrisdotca/chikyu-earth/catalogue";
 *
 * console.log(classOfElements(15.49, 0.0007), classOfElements(1.0027, 0.0002), classOfElements(0, 0));
 * ```
 */
export declare function classOfElements(meanMotion: number, eccentricity: number): OrbitClass | null;