Are the bandwidth synthesis delay and delay rate observables useful for VLBI imaging?

P. Charlot
1991 International Astronomical Union Colloquium  
AbstractThe Band Width Synthesis (BWS) delay and delay rate observables measured by VLBI are used in astrometry to determine positions of extragalactic radio sources with a precision of 0.001". At this level of precision, extragalactic radio sources exhibit "extended structures that induce significant effects in the measured BWS delays and delay rates. The question whether closure BWS delays and delay rates could supplement the amplitudes and closure phases for VLBI imaging is studied.
more » ... ry results for the radio source NRAO140 observed in July 1983 are presented.
doi:10.1017/s0252921100013518 fatcat:zk3nr2qy6be75pvv5awufe32gu