2014/02/14 by Liao, Shi-Long, Tang, Zheng-Hong, Qi, Zhao-Xiang
#FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM)
paper · doi:10.48550/arxiv.1406.4846
A relativistic delay model for space very long baseline interferometry (hereafter SVLBI) observation of sources at infinite distance is derived. In SVLBI, where one station is on a spacecraft, the orbiting station's maximum speed in an elliptical Earth orbit is much bigger than the ground VLBI (here after GVLBI), leading to a higher delay rate . The delay models inside the VLBI correlators are usually expressed as fifth-order polynomials in time that good for a limited time interval, which are evaluated by the correlator firmware and track the interferometer delays over a limited time interval. The higher SVLBI delay rate requires more accurate polynomial fitting and evalution, more frequent model updates.