An Assessment of Atmospheric Turbulence for CONT05 and CONT08

T. Nilsson and . Haas

Department of Radio and Space Science, Onsala Space Observatory, Chalmers University of Technology, Sweden

Oral presentation

Atmospheric turbulence causes fluctuations in the atmospheric delays of geodetic VLBI observations. Since these fluctuations are difficult to estimate precisely, they are expected to cause a degradation in the accuracy of the parameters estimated in a geodetic VLBI processing, e.g. relative station coordinates. We have developed a method for simulating atmospheric delays affected by a turbulent atmosphere. In this work we apply this method to simulate atmospheric delays and combine them with simulated clock errors and observation noise in order to obtain simulated VLBI observations. These simulated VLBI observations are then analyzed with the VLBI processing software SOLVE in order to evaluate the limitations that atmospheric turbulence puts on the accuracy of the VLBI results. We use different turbulence parameters in the simulations, ranging from the likely minimum values to the likely maximum values. The simulations concentrate on the two continuous VLBI campaigns CONT05 and CONT08, two 15 days long campaign with global VLBI networks. We compare the results from the simulations to those from processing of the actual data from these campaigns.