Geodetic space VLBI: the first test observations

Abstract The primary purpose of the Space VLBI Geodesy Demonstration Experiment (GEDEX) is to test how this new potential space geodetic technique works in practice using data from the first dedicated space VLBI satellite HALCA. Here we present our experience with a test observation made in December 1997. The data flow and pre-processing procedure is outlined. Initial results of preliminary data reduction using GINS, the CNES/GRGS software for analysis of space geodetic technique data, are presented.