public void createSubGrids() {
   this.subGrids = new ArrayList<SquareGrid>();
   double gridStep = this.size / 10;
   for (int i = 0; i < 10; i++) {
     double easting = this.SWEasting + gridStep * i;
     for (int j = 0; j < 10; j++) {
       double northing = this.SWNorthing + gridStep * j;
       SquareGrid sg =
           new SquareGrid(
               this.UTMZone, this.hemisphere, this.UTMZoneSector, easting, northing, gridStep);
       if (!sg.isOutsideGridZone()) this.subGrids.add(sg);
     }
   }
 }