Keywords:reference systems; catalogs; astrometry; celestial reference; interferometry; radio continuum; quasars; active galactic nuclei
Publisher:Pasadena, CA : Jet Propulsion Laboratory, National Aeronautics and Space Administration, 2011.
Citation:Reference Frames for Applications in Geosciences (REFAG2010), Marne-la-Vallee, France, October 4-8, 2010
Abstract:
A celestial reference frame at X/Kaband (8.4/32 GHz) has been constructed using fiftyone 24-hour sessions with the Deep Space Network. We report on observations which have detected 436 sources covering the full 24 hours of right ascension and declinations down to -45 deg. Comparison of this X/Ka-band frame to the S/X-band (2.3/8.4 GHz) ICRF2 shows wRMS agreement of 200 micro-arcsec ( as) in cos and 290 as in . There is evidence for zonal errors at the 100 as level. Known errors include limited SNR, lack of phase calibration, troposphere mismodelling, and limited southern geometry. The motivations for extending the ICRF to frequencies above 8 GHz are to access more compact source morphology for improved frame stability, to provide calibrators for phase referencing, and to support spacecraft navigation at Ka-band.
