GPS observations gathered during S-X VLBI experiments have been analyzed to extract the ionospheric delay along the signal path of the VLBI observations. These GPS-based delays have been compared with those obtained from S-X VLBI observations, with the rms of the differences less than 0.1 nanoseconds. In order to check the use of dual GPS data for the ionospheric calibration of single frequency VLBI observations, the baseline lengths estimated using dual VLBI data have been compared with those estimated from single band VLBI data calibrated with the GPS-based ionospheric delays. The differences between both results for European baselines were in the order of 3-5 parts per 10.

En: Sardón, E., Rius, A., Zarraoa, N. GPS inospheric delays. Publicación. Instituto de Astronomía y Geodesia, nº 185, 1993.

Peer reviewed