The article presents the reviewed and summarised research activities of Polish research groups on reference frames and reference networks in a period of 2019–2022. It contains the results on the implementation of latest resolutions on reference systems of the International Union of Geodesy and Geophysics and the International Astronomical Union focusing on changes in the consecutive issues of the Astronomical Almanac of the Institute of Geodesy and Cartography, Warsaw. It further presents the status of the implementation of the European Terrestrial Reference System 1989 (ETRS89) in Poland, monitoring the terrestrial reference frame, including research on global terrestrial reference frames, GNSS data analysis within the EUREF Permanent Network, research on GNSS receiver antenna phase centres, research on impact of non-tidal loading effects on position solutions, and on station velocities. Then the activities concerning the realization of ITRS and ETRS89 in Poland are discussed, including operational work of GNSS IGS/EPN stations as well as operational work of the laser ranging station of the International Laser Ranging Service, with special emphasis on the Polish active GNSS network for the realization of ETRS89 and maintenance of the vertical control network. Extensive research activities are observed in the field of implementation of the International Terrestrial Gravity Reference Frame in Poland, maintenance and modernization of gravity control network in Poland but also in Sweden, establishment of gravity control network in Ireland based on absolute gravity survey as well as maintenance of the national magnetic control network in Poland which is traditionally performed on a regular basis.

In the presented work, the conditions of the high-temperature and mechanochemical method for the synthesis of compound Sm ₅VO ₁₀ and their influence on its physicochemical properties were studied. The following methods were used for the study: X-ray powder diffraction (XRD), differential thermal analysis (DTA), infrared spectroscopy (FTIR), ultraviolet and visible light spectroscopy (UV–VIS–DRS), scanning electron microscopy (SEM-EDX), and laser beam diffraction spectrometry (LDS). Based on the results, it was determined that the compound Sm ₅VO ₁₀ is thermally stable in air atmospheres up to 1475 °C, crystallises in a monoclinic system, and its structure is made up of oxygen VO ₄ and SmO ₈ polyhedra. The estimated energy gap value for nanometric, mechanochemically obtained Sm ₅VO ₁₀ was about 3.20 eV, and for the microcrystalline, obtained with the high-temperature method, was about 2.75 eV. The established physicochemical characterisation of Sm ₅VO ₁₀ initially showed that the compound could find potential applications, e.g. as a photocatalyst for water purification or as a component of new optoelectronic materials.