The X/Ka-band Extragalactic Reference Frame

We have constructed an X/Ka-band (8.4/32 GHz) celestial reference frame using fty-nine 24hour sessions with the Deep Space Network. We detected 469 sources covering the full 24 hours of right ascension and declinations down to 45 . Comparison of 450 X/Ka sources in common with the S/X-band (2.3/8.4 GHz) ICRF2 shows weighted RMS (wRMS) agreement of 194 micro-arcsec ( as) in cos and 270 as in . There is evidence for systematic errors at the 100 as level. Known errors include limited SNR, lack of phase calibration, troposphere mismodeling, and limited southern geometry. Compared to X-band, Ka-band allows access to more compact source morphology and reduced core shift. Existing X/Ka data and simulated Gaia data predict a frame tie precision of 10-15 as (1- , per 3-D rotation component) with anticipated improvements reducing that to 5-10 as per component.