PHP to Javascript Arrays and GPS locations
var people = [ ['Type1', -33.890542, 151.274856],
               ['Type2', -33.923036, 151.259052],
               ['Type2', -34.028249, 151.157507],
               ['Type2', -33.80010128657071, 151.28747820854187],
               ['Type1', -33.950198, 151.259302]
             ];

// MySQL query in PHP
// btw, I'm storing GPS coordinates in decimal format like 51.123234
$varA = "(POW(SIN((gps_lat - $latitude) / 2 * 0.017453293), 2) + COS($latitude * 0.017453293)
        * COS(gps_lat * 0.017453293) * POW(SIN((gps_lon - $longtitude) / 2 * 0.017453293), 2))";

$query = "SELECT *, (6378.140 * 2 * ATAN2(SQRT($varA), SQRT(1-$varA))) AS distanceInKm ";
$query += 'FROM Office ORDER BY distanceInKm');

$mysqli->query($query);
// ...

// the magic constant 0.017453293 is PI / 180 (just check the link below).

dlon = lon2 - lon1
dlat = lat2 - lat1
a = (sin(dlat/2))^2 + cos(lat1) * cos(lat2) * (sin(dlon/2))^2
c = 2 * atan2(sqrt(a), sqrt(1-a))
d = R * c