2.4 Pointing Errors
The accuracy of the pointing increases with the observing frequency, i.e. as the antenna beam width decreases.
It is commonly assumed that :
δp = pointing accuracy
HPBW = -3 dB beam width (main lobe)
For the Medicina antenna the values are listed in Table 2.4 :
Tab. 2.4 : Beam and pointing errors
The systematic errors are usually quite high (several arcminute). A pointing model has been derived from observations of radio sources with accurately known coordinates.
Once the model has been applied, the residual error is 0.13' (both in azimuth and elevation).