Из приведенного ниже скрипта вы можете получить лат и лог, а затем легко найти точку
<!doctype html>
<html lang="en">
<head>
<title>Using the scripts in web pages</title>
<meta charset="utf-8">
<script defer src="//cdn.rawgit.com/chrisveness/geodesy/v1.1.2/latlon-spherical.js"></script>
<script defer src="//cdn.rawgit.com/chrisveness/geodesy/v1.1.2/dms.js"></script>
<script>
document.addEventListener('DOMContentLoaded', function() {
document.querySelector('#calc-dist').onclick = function() {
const lat1 = document.querySelector('#lat1').value;
const lon1 = document.querySelector('#lon1').value;
const lat2 = document.querySelector('#lat2').value;
const lon2 = document.querySelector('#lon2').value;
const p1 = new LatLon(Dms.parseDMS(lat1), Dms.parseDMS(lon1));
const p2 = new LatLon(Dms.parseDMS(lat2), Dms.parseDMS(lon2));
const dist = parseFloat(p1.distanceTo(p2).toPrecision(4));
document.querySelector('#result-distance').textContent = dist;
}
});
</script>
</head>
<body>
<form>
Lat 1: <input type="text" name="lat1" id="lat1">
Lon 1: <input type="text" name="lon1" id="lon1">
Lat 2: <input type="text" name="lat2" id="lat2">
Lon 2: <input type="text" name="lon2" id="lon2">
<button type="button" id="calc-dist">Calculate distance</button>
<output id="result-distance"></output> metres
</form>
</body>
</html>