lat/long distance and square calculation

haversine.php

<?php

function distance($latFrom, $lonFrom, $latTo, $lonTo) {
  $earthRadius = 6371000; // in meter

  // convert from degrees to radians
  $latFrom = deg2rad($latFrom);
  $lonFrom = deg2rad($lonFrom);
  $latTo = deg2rad($latTo);
  $lonTo = deg2rad($lonTo);

  $latDelta = $latTo - $latFrom;
  $lonDelta = $lonTo - $lonFrom;

  $angle = 2 * asin(sqrt(pow(sin($latDelta / 2), 2) +
    cos($latFrom) * cos($latTo) * pow(sin($lonDelta / 2), 2)));
  return $angle * $earthRadius;
}


function square($lat) {
  $earthRadius = 6371000; // in meter

  // convert from degrees to radians
  $lat = deg2rad($lat);
  $latDelta = 0;
  $lonDelta = M_PI*1.0;

  $angle = 2 * asin(sqrt(pow(sin($latDelta / 2), 2) +
    cos($lat) * cos($lat) * pow(sin($lonDelta / 2), 2)));
  $one_degree = $angle * $earthRadius / 180;
  $lon = 1 / ($one_degree / 12000);
  $lat = 1 / (111000 / 12000);
  return [$lat, $lon];
}

print(distance(0.0, 0.0, 0.0, -180.0) . "\n");
print(distance(50.03, 8.48, 50.03, 8.62) . "\n\n");

print_r(square(0.0));
print_r(square(50.03));

print("... WHERE lat >" . (50.03 - square(50.03)[0]/2) . " AND lat <" . (50.03 + square(50.03)[0]/2) . "...\n");
print("... WHERE lon >" . (8.54 - square(50.03)[1]/2) . " AND lon <" . (8.54 + square(50.03)[1]/2) . "...\n");