Do VLBA tests. Ongoing efforts are merely listed here, to be discussed elsewhere. Tests indicate improvements from a combination of enhanced pointing model, and offsets referenced to 1.3cm or 7mm. We may need notch filters eventually, but the frequency is not certain. Vehicle Radars at 75GHz should not be a problem.
Methanol masers lie outside of any protection here.
7mm data were taken simultaneously, as a sanity check, and to measure the opacity. The efficiency difference between PT and LA is under investigation. We urgently need to resolve why amplifiers with noise under 50K result in a Tsys on telescope of 150K or more at PT - a detailed breakdown of the noise added by the polarizer, horn, mixer, etc. is needed. There seems to have been a gradual increase of Tsys since installation. TcalTAB is the cal value in the table used by VLBA Operations.