docs: def _format_lat(self, lat):
          ''' Format latitude to fit the image name '''
  
          if self.ppd in [4, 8, 16, 32, 64]:
              latcenter = '000N'
          elif self.ppd in [128]:
              if lat < 0:
                  latcenter = '450S'
              else:
                  latcenter = '450N'
  
          return latcenter