Mapping exif data to long/lat

Question

I'm using the php exif_read_data function to get the long and lat, then I'm converting them into a format the google can use, however they always seem to be a few miles out. The same country, just not the right position (iPhoto will give me the correct position, however). The code is as follows

public function get_location() {
    global $the_image;

    if(!empty($the_image)) {
      $exif = $this->get_exif();

      $degLong = $exif['GPSLongitude'][0];
      $minLong = $exif['GPSLongitude'][1];
      $secLong = $exif['GPSLongitude'][2];
      $refLong = $exif['GPSLongitudeRef'];

      $degLat = $exif['GPSLatitude'][0];
      $minLat = $exif['GPSLatitude'][1];
      $secLat = $exif['GPSLatitude'][2];
      $refLat = $exif['GPSLatitudeRef'];

      $long = $this->to_decimal($degLong, $minLong, $secLong, $refLong);
      $lat  = $this->to_decimal($degLat, $minLat, $secLat, $refLat);
      echo $long . "<br />" . $lat . "<br/>";

    } else {
      echo "Supply an image";
    }
}

  function to_decimal($deg, $min, $sec, $hem){
    $d = $deg + ((($min/60) + ($sec/3600))/100);
    return ($hem =='S' || $hem=='W') ?  $d*=-1 : $d;
  }

Can anyone see what would make it return the wrong data, is my to_decimal function wrong?

Answer 1

You devide the minutes and seconds by 100, but well, you shouldn't:

$d = $deg + ((($min/60) + ($sec/3600))/100);

should be:

$d = $deg + (($min/60) + ($sec/3600));

one minute is 1/60 degree and a second is 1/60 minute.

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for a more thorough answer, see here: PHP extract GPS EXIF data