set satellite name using (cf. notes on file names in `altimetry.data.alti_data.__init__`)

def set_sats(self):
        '''
        set satellite name using (cf. notes on file names in `altimetry.data.alti_data.__init__`)
        '''
        if self.count == 0 : return
        
        for enum in enumerate(self.filelist):
            
            if hasattr(self, 'id') : sat = self.id
            elif (self.datatype == 'DT') | (self.datatype == 'NRT') | (self.datatype == 'PISTACH') : sat = [enum[1].split('_')[2]]
            elif (self.datatype == 'CTOH') : sat = [enum[1].split('.')[-4]]
            else : sat = 'N/A'
            
            if len(sat) == 1 : sat*self.filelist_count[enum[0]]
            self.sat=np.append(self.sat,sat)
            
        self.sat=np.ma.array(self.sat,mask=False)