The coordinates of radio telescopes, which are part of the emerging VLBI Global Observing System, were estimated in a least squares unconstrained adjustment. The higher number of observations per time with better sky coverage, which these telescopes can produce, was optimally utilized by testing different intervals for the tropospheric delay estimation. We found that a short estimation interval of 15 min for the tropospheric gradients with a 45 min interval for the zenith wet delay perform best.

In this study we compare meteorological observations from a set of different measuring devices with each other in order to derive information about their quality and mutual consistency. We consider data from terrestrial measuring devices, satellite observations, space observations, weather balloons and weather models provided by weather agencies. The results in general show very good accordance and interchangeability between the various solutions.