Most people don't know the difference between Latitude and Longitude. Latitude lines are the horizontal ones that cross the earth and longitude are the ones that are vertical: Finding latitude is easy

$stmt = $pdodb->prepare("SELECT field1, field2, SQRT(     POW(69.1 * (dblat - :dblat), 2) +     POW(69.1 * (:dblon - dblon) * COS(dblat / 57.3), 2)) AS distance