W.wilson and M.Wieringa will look after this. They checked the pointing every half-hour. The results are shown in figure 1 . The bottom two plots show, on the left the actual pointing error, and on the right the pointing error that would have been present had reference pointing not been used. The reasons are understood, and are now trapped.
Further experience is needed, and observers are encouraged to give the system a trial.
SAC - R.S's recent problems with attenuators Bob found in a recent mosaicing experiment that the attenuators never settled down. It is thought that this problem has been around for a few months. Mark Wieringa will investigate. The images are available at the same URL dqo status . At present the rms noise is still high - 0.13 mJy where 0.03 mJy are expected.