Litvinov, DA and Nunes, NV and Filetkin, AI and Bartel, N and Gurvits, LI and Molera Calves, G and Rudenko, VN and Zakhvatkin, MV, The antenna phase center motion effect in high-accuracy spacecraft tracking experiments, Advances in Space Research, 68, (10) pp. 4274-4291. ISSN 0273-1177 (2021) [Refereed Article]
Copyright 2021 COSPAR. Published by Elsevier B.V. All rights reserved.
We present an improved model for the antenna phase center motion effect for high-gain mechanically steerable ground-based and spacecraft-mounted antennas that takes into account non-perfect antenna pointing. Using tracking data of the RadioAstron spacecraft we show that our model can result in a correction of the computed value of the effect of up to 2 x 10(-14) in terms of the fractional frequency shift, which is significant for high-accuracy spacecraft tracking experiments. The total fractional frequency shift due to the phase center motion effect can exceed 1 x 10(-11) both for the ground and space antennas depending on the spacecraft orbit and antenna parameters. We also analyze the error in the computed value of the effect and find that it can be as large as 4 x 10(-14) due to uncertainties in the spacecraft antenna axis position, ground antenna axis offset and misalignment, and others. Finally, we present a way to reduce both the ground and space antenna phase center motion effects by several orders of magnitude, e.g. for RadioAstron to below 1 x 10(-16), by tracking the spacecraft simultaneously in the one-way downlink and two-way phase-locked loop modes, i.e. using the Gravity Probe A configuration of the communications links.
|Item Type:||Refereed Article|
|Keywords:||Antenna phase center motion, high-gain antenna, space-VLBI, RadioAstron, gravitational redshift, gravity Probe A|
|Research Division:||Physical Sciences|
|Research Group:||Astronomical sciences|
|Research Field:||Planetary science (excl. solar system and planetary geology)|
|Objective Division:||Expanding Knowledge|
|Objective Group:||Expanding knowledge|
|Objective Field:||Expanding knowledge in the physical sciences|
|UTAS Author:||Molera Calves, G (Dr Guifre Molera Calves)|
|Web of Science® Times Cited:||1|
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