Inverse Multiview I: Multi-Calibrator inverse phase referencing for Microarcsecond VLBI Astrometry [IMA]

http://arxiv.org/abs/2205.00092


Very Long Baseline Interferometry (VLBI) astrometry is a well established technique for achieving $\pm10~\mu$as parallax accuracies at frequencies well above 10~GHz. At lower frequencies, uncompensated interferometer delays associated with the ionosphere play the dominant role in limiting the astrometric accuracy. Multiview is a novel VLBI calibration method, which uses observations of multiple quasars to accurately model and remove time-variable, directional-dependent changes to the interferometer delay. Here we extend the Multiview technique by phase referencing data to the target source (“inverse Multiview”) and test its performance. Multiple observations with a four-antenna VLBI array operating at 8.3~GHz show single-epoch astrometric accuracies near $20~\mu$as for target-reference quasar separations up to about 7 degrees. This represents an improvement in astrometric accuracy by up to an order of magnitude compared to standard phase referencing.

Read this paper on arXiv…

L. Hyland, M. Reid, S. Ellingsen, et. al.
Tue, 3 May 22
52/82

Comments: 11 pages, 5 figures