VLBI2010 simulations at IGG Vienna

J. Wresnik, J. Boehm, A. Pany, H. Schuh

Institute of Geodesy and Geophysics (IGG) / Vienna University of Technology, Austria

Oral presentation

The goals of the next generation VLBI system, VLBI2010, are to achieve 1-mm position accuracy over a 24-hour observing session and to carry out continuous observations, i.e. observing seven days per week. Initial results shall be delivered within 24 hours after taking the data. These goals require a completely new technical and conceptual design of VLBI measurements on which the VLBI2010 Committee (V2C) has worked in the last two years. The IGG participates in the V2C simulation group with Monte Carlo simulations. The simulator produces artificial group delays by modeling the stochastic processes caused by station clocks, wet troposphere, and additional system errors. The clocks are simulated with a random walk plus integrated random walk, zenith wet delays are derived from a turbulence model, and system errors are represented by white noise. The Monte Carlo simulator is implemented in a modified version of the software package OCCAM and the Kalman Filter approach of OCCAM was applied. Various schedules assuming antennas with different slew speeds (from 1.5 °/s to 12°/s in azimuth and 0.7 °/s to 3.1 °/s in elevation) are compared w.r.t. baseline length repeatabilities and rms values of station position residuals. The investigation shows that antennas faster than 6°/s in azimuth and 2.1°/s in elevation are definitely needed to achieve the ambitious goals described above. Different scheduling strategies, such as using observation schedules with uniform sky coverage, are also tested.

oral presentation