Accuracy or positions and parallaxes

Two figures from a report soon to be placed on arXiv: 

Astrometric Accuracy of Positions

Erik Høg, Niels Bohr Institute, Copenhagen University

Figure 1. The accuracy of observed star positions for 2000 years, marked with red color for observations from the ground and with blue from space. The accuracy was greatly improved shortly before 1600 AD by the Landgrave in Kassel and by Tycho Brahe in Denmark. The following 400 years brought even larger but much more gradual improvement before space techniques with the European Hipparcos satellite started a new era of astrometry. Catalogs before 1900 are plotted at the mean epoch of observation, but after 1900 at the time of publication. – The 17 million brightest stars in the sky have accuracies of 0.014 milliarcsec

Figure 1b. Astrometric accuracy, update of Fig.5 from 1995 to our 2024 knowledge, including both parallaxes and positions. Gaia produces millions of accurate proper motions and parallaxes in addition to the positions shown in this diagram, see Gaia DR3 (2022). The important astrometry from space obtained with the HST should also be mentioned, and the very accurate astrometry by interferometry with radio telescopes.