@staticmethod
def get_tile_xy(latitude, longitude):
    x = int((longitude + 180.0) / 5.0) + 1
    y = int(-latitude / 5.0) + 12
    return x, y

@staticmethod
def get_tile_name_xy(x, y):
    return "srtm_{0:02d}_{1:02d}".format(x, y)

def get_tile_name(self, latitude, longitude):
    x, y = self.get_tile_xy(latitude, longitude)
    return self.get_tile_name_xy(x, y)