The Celestial Reference Frame at X/Ka-band (8.4 / 32 GHz)
Abstract
A celestial reference frame at X/Ka-band (8.4/32 GHz) has been constructed using fifty-one 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 in a cos delta and 290 micro-arcsec in delta. There is evidence for zonal errors at the 100 micro-arcsec 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.
- Publication:
-
Proc. Reference Frames for Applications in Geosciences (REFAG2010
- Pub Date:
- October 2010
- Bibcode:
- 2010rfag.confE...1J
- Keywords:
-
- Celestial Reference Frame;
- Reference Frame;
- ICRF;
- astrometry;
- VLBI;
- X/Ka-band;
- 32 GHz;
- Deep Space network;
- quasar;
- Active Galactic Nuclei