src/utils/geoUtils.ts

export function getDistanceFromLatLonInKm(lat1: number, lon1: number, lat2: number, lon2: number) {
    var R = 6371; // Radius of the earth in km
    var dLat = deg2rad(lat2 - lat1);
    var dLon = deg2rad(lon2 - lon1);
    var a =
        Math.sin(dLat / 2) * Math.sin(dLat / 2) +
        Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) *
        Math.sin(dLon / 2) * Math.sin(dLon / 2)
        ;
    var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
    var d = R * c; // Distance in km
    return d;
}

function deg2rad(deg: number) {
    return deg * (Math.PI / 180)
}