@staticmethod
def _str_data(trajectory):
    """
        Returns a string representation of the DAF data block provided in the
        input ``trajectory``.

        Parameters
        ----------
        trajectory: list
           n-element list of dictionary providing the DAF data block points to
           be converted to a string representation.

        Returns
        -------
        str
           a string representation of the DAF data block provided in the input
           ``trajectory``.

        """
    data = """!                     Position         Altitude in m            SubPoint        Cam. dist in m  Velocity in km/s
!###   Time  Bright   x      y       h       +/-h  +/-pos   lon/deg  lat/deg     dist   +/-dist     v       +/-v
"""
    for point in trajectory:
        data += str.format(' %03i  %05.2f %6.1f  %5.3f  %5.3f  %8.1f' % (
            point['###'], point['Time'], point['Bright'], point['x'], point
            ['y'], point['h']))
        try:
            data += str.format('  %6.1f' % point['dh'])
        except TypeError:
            data += '  ' + point['dh']
        data += str.format('  %5.1f  %8.3f  %7.3f  %9.1f' % (point['dpos'],
            point['lon'], point['lat'], point['dist']))
        try:
            data += str.format('  %6.1f' % point['ddist'])
        except TypeError:
            data += '  ----.-'
        try:
            data += '  %7.3f' % point['v']
        except TypeError:
            data += '   --.---'
        try:
            data += '  %7.3f' % point['dv']
        except TypeError:
            data += '   --.---'
        data += '\n'
    return data
