def read(self):
        """Read the data.
        """
        tic = datetime.now()
        with open(self.filename, "rb") as fp_:
            header = np.memmap(fp_, dtype=_HEADERTYPE, mode="r", shape=(1, ))
            data = np.memmap(fp_, dtype=_SCANTYPE, offset=22016, mode="r")

        logger.debug("Reading time %s", str(datetime.now() - tic))

        self._header = header
        self._data = data