Abstract:
A 220 GHz tipping radiometer is in operation at the Indian Astronomical Observatory, Mt Saraswati, Digpa-ratsa Ri, Hanle (Latitude 32degrees 46' 46".3 N, Longitude 78degrees 57' 51".1 E, Altitude 4500 in above msl) for continuous monitoring of sky opacity at this frequency. We describe here the working principle, data acquisition method and data reduction scheme of the radiometer. We also present some preliminary results on the 220 GHz zenith optical depth at Mt. Saraswati which shows that optical depths less than 0.10 can be achieved for nearly 75% of the time during the six colder months (October to March).
