Local- ie Expe imen s o Chinese VLBI S a ions
Xuan He1, Fengchu Shu1, Minghui Xu2, Yidan Huang1, Jiangying Gan1, Bo Xia1, Cong Liu1
1Shanghai As onomical Obse a o y, Chinese Academy o Sciences
2GFZ Helmhol z Cen e o Geosciences
[email p o ec ed]
Abs ac
This epo p esen s local- ie expe imen s using h ee co-loca ed VLBI s a ions in China: Tianma and Sheshan in Shanghai, and
U umqi. The VGOS an ennas we e u ilized in mixed-mode obse a ions ac oss he con en ional S/X bands, ollowed by co ela ion o
X-band-only da a and subsequen pos -co ela ion analysis. Phase delay analysis was pe o med o de e mine he ela i e coo dina es
o hese co-loca ed VLBI an ennas. Mo eo e , TIANMA13 and SESHAN13, o ming a baseline o 6km long, joined a ew VGOS 24-h
sessions oge he . We a emp ed o de e mine he baseline ec o using phase delay app oach.
Expe imen s
TIANMA13-TIANMA65 ~179m SESHAN25-SESHAN13 ~55m
URUMQI-URUMQI13 ~374m
Da a o Phase Delay Resea ch:
• S/X Mixed-mode Tag-along Expe imen s: 7 sessions (Legacy + VGOS
s a ions; X-band only)
• IVS VGOS-OPS Expe imen : 1 session (Shanghai VGOS s a ions; B&C
bands; Only Y-pola iza ion was employed)
Session
Time
S a ions
Session
Time
S a ions
AOV056
2021-02-03
ShS6
RD2303
2023-04-12
T6T1
AOV057
2021-03-22
ShS6
AOV082
2023-04-26
T6T1
AOV058
2021-04-27
T6T1
APSG53
2023-08-30
U Um
AOV062
2021-08-24
ShS6
VO5148
2025-05-28
S6T1
Da a P ocessing - Mixed-Mode
Da a P ocessing - VGOS Mode
• Phase delay solu ions (blue) yield supe io p ecision, wi h
smalle WRMS delay esiduals and baseline ec o o mal
e o s han g oup delay solu ions (black)
• Phase delay solu ions om Tianma s a ions show be e
epea abili y ac oss sessions
Fu u e Plans
• In es iga e why he phase delay solu ions in AOV057/AOV062
we e ailed.
• Pe o m mo e dedica ed local- ie expe imen s.
• P ocess all SESHAN13-TIANNA13 VGOS da a using he
pipeline de eloped in VO5148, conside ing pola iza ion
combina ion me hod.
Si e
Session
WRMS
/ps
Obs
Used
Leng h
/mm
X Comp
/mm
Y Comp
/mm
Z Comp
/mm
Sheshan
AOV056
9.3
417
55511.7
± 0.4
-40597.8
± 0.8
3903.6
± 1.2
-37658.1
± 0.8
20.4
419
55507.5
± 1.0
-40585.7
± 1.7
3903.1
± 2.6
-37665.0
± 1.7
Tianma
AOV058
4.2
88
178526.5
± 0.5
93064.1
± 0.8
-17027.1
± 1.2
151396.4
± 0.8
34.3
67
178537.6
± 4.8
93053.4
± 8.3
-17007.0
± 11.6
151418.4
± 7.8
RD2303
6.7
117
178529.1
± 1.2
93063.7
± 1.0
-17022.0
± 1.6
151400.3
± 1.5
18.5
117
178533.3
± 3.2
93058.6
± 2.7
-17013.0
± 4.4
151409.4
± 4.0
AOV082
6.9
216
178527.9
± 0.5
93065.5
± 0.7
-17027.8
± 1.0
151397.1
± 0.7
11.2
218
178528.1
± 0.8
93045.7
± 1.1
-17000.4
± 1.7
151412.6
± 1.3
U umqi
APSG53
7.1
403
373621.9
± 0.2
-361562.5
± 0.2
66934.9
± 0.8
-66224.1
± 0.7
15.5
413
373621.7
± 0.5
-361562.0
± 0.6
66932.2
± 1.7
-66228.3
± 1.5
Sheshan
-Tianma
VO5148
14.4
516
6051321.2
± 0.5
4845144.5
± 1.1
3524517.6
± 1.5
-849021.9
± 1.2
17.7
520
6051323.4
± 0.5
4845148.7
± 1.3
3524514.6
± 2.0
-849026.0
± 1.4
VLBI co-loca ed an ennas in
China, loca ed in Shanghai (
Sheshan and Tianma ) and
U umqi.
10 h IVTW
21-25 Oc 2025
Chalme s, Go henbu g
Resul & Analysis
P elimina y Phase-Delay P ocessing o Pu e VGOS
Expe imen s:
• Pipeline: Based on s anda d VGOS con ol iles
• Bands: B&C channels we e selec ed (ionosphe ic sea ch disabled)
• Fi ing: F inge i ing was pe o med using Y-pola iza ion only
No e:
• SESHAN25 (Sh), SESHAN13 (S6), TIANMA65 (T6), TIANMA13
(T1), URUMQI (U ), URUMQI13 (Um)
• AOV057 and AOV062 ailed o ex ac phase delay
• VO5148, wo VGOS an ennas a e abou 6km
