/** const for kilometers per degree on the earth, 111.19 */
export declare const kmPerDeg = 111.19;
/**
 * Convert degrees into kilometers along the earth surface
 *
 * @param deg degrees to convert
 * @returns kilometers
 */
export declare function degtokm(deg: number): number;
/**
 * Convert kilometers into degrees along the earth surface
 *
 * @param km kilometers to convert
 * @returns degrees
 */
export declare function kmtodeg(km: number): number;
export declare class DistAzOutput {
    delta: number;
    az: number;
    baz: number;
    stalat: number | undefined;
    stalon: number | undefined;
    evtlat: number | undefined;
    evtlon: number | undefined;
    constructor(delta: number, az: number, baz: number);
    get distance(): number;
    get distanceKm(): number;
    get distanceDeg(): number;
    get azimuth(): number;
    get backazimuth(): number;
}
/**
 *
 * Returns a simple object (DistAzOutput) with:
 *```
 *     delta       => Great Circle Arc distance in degrees
 *     az          => Azimuth of pt. 1 wrt pt. 2 in degrees
 *     baz         => Azimuth of pt. 2 wrt pt. 1 in degrees
 *```
 *
 * azimuth is if you stand at point 2 and measure angle between north
 *   and point 1. I.E. point 1 is the station and point 2 is the event.
 *
 * @param lat1 Latitude of first point (station) (+N, -S) in degrees
 * @param lon1 Longitude of first point(station) (+E, -W) in degrees
 * @param lat2 Latitude of second point (event)
 * @param lon2 Longitude of second point (event)
 * @returns delta, az, baz in a DistAzOutput
 */
export declare function distaz(lat1: number, lon1: number, lat2: number, lon2: number): DistAzOutput;