Jing Sun
Type of contribution: oral
Session: 1

New observing strategies with twin telescopes for geodetic VLBI

Jing Sun,Vienna University of Technology Tobias Nilsson, Vienna University of Technology Johannes Boehm, Vienna University of Technology Harald Schuh, Vienna University of Technology

The concept of twin radio telescopes enables a lot of new observation strategies. These are investigated by developing the mathematical basis in terms of observation equations (single, double or even triple differences), creating new observation schedules, doing careful simulations, and finally by analyzing results. Advantages are obtained by assuming the same troposphere above the twin telescopes and connecting them to the same H-maser clock. Three different observing strategies are investigated. The first is that both twin telescopes point simultaneously to the same radio source ('array mode') to increase the sensitivity and counteract the troposphere effect. The second is that both radio telescopes record signals of different sources at the same time, then different subnets are tied via the same site. In the third strategy, one telescope is slewing while the other radio telescope is still tracking a source, thus 'continuous' observations can be realized because one of the twin radio telescopes is always on source. Hence the high slewing rates of the twin telescopes will be fully exploited for the various new observing strategies. The scheduling package of the Vienna VLBI Software (VieVS) will be used to develop different schedules allowing all the options and combinations mentioned above.