THE MOBILE VLBI CAMPAIGNS IN NORWAY (1989-1993)

Since 1989 several mobile VLBI campaigns have been carried out in Euro pe with a total of 14 sites occupied. The Norwegian stations at Tromso and Trysil are the only mobile VLBI stations in Europe observed in mo re than one epoch, so they have produced the most interesting data fro m these campaigns. Tromsro is the only station observed in the two sum mer campaigns (1989 and 1992), while Trysil has been the winter site f or MV-2 since late 1991 until the spring of 1993. In this paper we des cribe the mobile VLBI campaigns in Norway including the observational work and the detailed geodetic analysis performed with OCCAM V3.3. We have also analyzed a series of GPS data sets from Tromso in order to c heck the reliability of the VLBI results for that station. The results reveal the need for a very careful design of mobile VLBI experiments, in particular regarding the consistency of the network and of the obs ervation schedules, and the special care that is required in the analy sis of the mobile VLBI data in order to achieve significant conclusion s.