public double metersToPixels(){
  double screenCenterLat=screenTopLeft.latitude - screenSize.latitude / 2;
  double metersToLon=1 / (Util.LON_TO_METERS_AT_EQUATOR * Math.cos(screenCenterLat / 180 * Math.PI));
  return screenSize.longitude / windowWidth * metersToLon;
}

public double metersToPixels ( ) { double screenCenterLat = screenTopLeft . latitude - screenSize . latitude / 2 ; double metersToLon = 1 / ( Util . LON_TO_METERS_AT_EQUATOR * Math . cos ( screenCenterLat / 180 * Math . PI ) ) ; return screenSize . longitude / windowWidth * metersToLon ; }
returns the ratio of meters to pixels at the center of the screen
