/**
* Calculate the distance in Km
* Sourced from StackOverflow (https://stackoverflow.com/questions/27928/calculate-distance-between-two-latitude-longitude-points-haversine-formula)
* This is the 'fastest' algorithm apparently
*
* @param lat1
* @param lon1
* @param lat2
* @param lon2
* @returns number The distance in km
*/
export declare function getDistanceFromLatLonInKm(lat1: number, lon1: number, lat2: number, lon2: number): number;