eCite Digital Repository

VLBI observations to the APOD satellite


Sun, J and Tang, G and Shu, F and Li, X and Liu, S and Cao, J and Hellerschmeid, A and Bohm, J and McCallum, L and McCallum, J and Lovell, J and Haas, R and Neidhardt, A and Lu, W and Han, S and Ren, T and Chen, L and Wang, M and Ping, J, VLBI observations to the APOD satellite, Advances in Space Research, 61, (3) pp. 823-829. ISSN 0273-1177 (2018) [Refereed Article]

Copyright Statement

Copyright 2017 Published by Elsevier Ltd on behalf of COSPAR.

DOI: doi:10.1016/j.asr.2017.10.046


The APOD (Atmospheric density detection and Precise Orbit Determination) is the first LEO (Low Earth Orbit) satellite in orbit co-located with a dual-frequency GNSS (GPS/BD) receiver, an SLR reflector, and a VLBI X/S dual band beacon. From the overlap statistics between consecutive solution arcs and the independent validation by SLR measurements, the orbit position deviation was below 10 cm before the on-board GNSS receiver got partially operational. In this paper, the focus is on the VLBI observations to the LEO satellite from multiple geodetic VLBI radio telescopes, since this is the first implementation of a dedicated VLBI transmitter in low Earth orbit. The practical problems of tracking a fast moving spacecraft with current VLBI ground infrastructure were solved and strong interferometric fringes were obtained by cross-correlation of APOD carrier and DOR (Differential One-way Ranging) signals. The precision in X-band time delay derived from 0.1 s integration time of the correlator output is on the level of 0.1 ns. The APOD observations demonstrate encouraging prospects of co-location of multiple space geodetic techniques in space, as a first prototype.

Item Details

Item Type:Refereed Article
Keywords:APOD, Very Long Baseline Interferometry, GNSS, SLR, space ties
Research Division:Earth Sciences
Research Group:Geophysics
Research Field:Geodesy
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the earth sciences
UTAS Author:McCallum, L (Dr Lucia McCallum)
UTAS Author:McCallum, J (Dr Jamie McCallum)
UTAS Author:Lovell, J (Dr Jim Lovell)
ID Code:122891
Year Published:2018
Web of Science® Times Cited:5
Deposited By:Mathematics and Physics
Deposited On:2017-12-05
Last Modified:2019-02-27

Repository Staff Only: item control page