  In this work, we report on activities focusing on improving the observation
strategy of the Very Long Baseline Interferometry (VLBI) Global Observing
System (VGOS). During six dedicated 24-hour Research and Development (R&D)
sessions conducted in 2022, the effectiveness of a signal-to-noise ratio
(SNR)-based scheduling approach with observation times as short as 5-20 seconds
was explored. The sessions utilized a full 8 Gbps observing mode and
incorporated elements such as dedicated calibration scans, a VGOS frequency
source-flux catalog, improved sky-coverage parameterization, and more.
  The number of scans scheduled per station increased by 2.34 times compared to
operational VGOS-OPS sessions, resulting in a 2.58 times increase in the number
of observations per station. Remarkably, the percentage of successful
observations per baseline matched the fixed 30-second observation approach
employed in VGOS-OPS, demonstrating the effectiveness of the SNR-based
scheduling approach.
  The impact on the geodetic results was examined based on statistical
analysis, revealing a significant improvement when comparing the VGOS-R\&D
program with VGOS-OPS. The formal errors in estimated station coordinates
decreased by 50 %. The repeatability of baseline lengths improved by 30 %,
demonstrating the enhanced precision of geodetic measurements. Furthermore,
Earth orientation parameters exhibited substantial improvements, with a 60 %
reduction in formal errors, 27 % better agreement w.r.t. IVS-R1/R4, and 13 %
better agreement w.r.t. IERS EOP 20C04.
  Overall, these findings strongly indicate the superiority of the VGOS-R&D
program, positioning it as a role model for future operational VGOS
observations.

Instrumentation and Methods for Astrophysics