The pointing parameters of the antennas are measured monthly under calm nighttime conditions. The antenna model, using these parameters, suffices under good weather to allow blind pointing to an accuracy of about 10 arcsec rms. The pointing accuracy in daytime is a little worse, due to the effects of solar heating of the antenna structures.
Moderate winds have a very strong effect on both pointing and antenna figure.
Observations at these bands in winds significantly in excess of this limit are not advisable, and users should consider moving to a lower frequency. To achieve better pointing, we have added a capability for repeated calibration and correction of the local pointing error during astronomical observations. The local pointing corrections thus measured can then be applied to subsequent target observations. Proximity of the reference calibrator to the source position is of paramount importance. The calibrator should have at least 300 mJy flux density and be unresolved on all baselines to ensure an accurate solution.