  The Gaia celestial reference frame (Gaia-CRF) will benefit from a close
assessment with independent methods, such as Very Long Baseline Interferometry
(VLBI) measurements of radio stars at bright magnitudes. However, obtaining
full astrometric parameters for each radio star through VLBI measurements
demands a significant amount of observation time. This study proposes an
efficient observing strategy that acquires double-epoch VLBI positions to
measure the positions and proper motions of radio stars at a reduced cost. The
solution for CRF link compatible with individual VLBI position measurements is
introduced, and the optimized observing epoch scheduling is discussed. Applying
this solution to observational data yields results sensitive to sample increase
or decrease, yet they remain consistently in line with the literature at the
1-sigma level. This suggests the potential for improvement with a larger sample
size. Simulations for adding observations demonstrate the double-epoch strategy
reduces CRF link parameter uncertainties by over 30% compared to the
five-parameter strategy.
