The X/Ka-band (8.4/32 GHz) 2023a Celestial Reference Frame

The X/Ka-band (8.4/32 GHz) Celestial Reference Frame became one of three components of the ICRF-3 in 2018. In the five years since, the X/Ka data set has increased by about 75% as well as adding the much needed north-south geometry from Japan to Australia. The latest solutions have median formal precisions of 45 μas in α cosδ and 65 μas in δ.
The large spherical harmonic distortions seen in the ICRF3-XKa are greatly improved with the Z-dipole term reduced from 314 μas to a nearly statistically insignificant -85 +- 44 μas and with the quadrupole 2,0 magnetic term reduced to 158 +- 16 μas. We note that the X/Ka frame is derived from a limited geometry of only five observing sitesof which the two DSN baselines dominate with over 80% of the total data thus creating a susceptibility of this frame to geometric distortions. The prospects for future improvements are bright and we expect the distortions to be reduced as more data from the ESA Malargüe and JAXA Misasa stations are added.