TY - JOUR

T1 - Analysis on motion of Earth's center of mass observed with CHAMP mission

AU - Guo, Jinyun

AU - Han, Yanben

AU - Hwang, Chein-way

PY - 2008/10/1

Y1 - 2008/10/1

N2 - Geocenter motion (GCM) is one important topic for constructing and maintaining the terrestrial reference frame and its applications. GCM is studied from CHAMP with the multi-step approach in this paper. Geometric orbits of CHAMP in 2001-2006 are precisely determined with the kinematic method only from the satellite-borne GPS zero-difference data. Then a GCM time series is estimated from the precise kinematic orbits based on the theory of satellite dynamics to fit the CHAMP's real geometric orbits. We compare the series with the geocenter series used in ITRF2005. Then the GCM series are analyzed with Fourier transform and wavelet transformation. The mean motions within 6 years in TX, TY and TZ directions are respectively 0.8 mm, 2.2 mm, and 7.9 mm. The trends of GCM in the three directions are 0.495 mm/a, -0.004 mm/a, and 1.309 mm/a, respectively. The long-term movement (2001-2006) indicates that the crustal figure is changing. The seasonal variations are the main component which may be excitated by the mass redistribution of Earth's fluid layer, e.g. ocean, atmosphere and continental water. The inter-annual variations are also found in the GCM series measured with CHAMP.

AB - Geocenter motion (GCM) is one important topic for constructing and maintaining the terrestrial reference frame and its applications. GCM is studied from CHAMP with the multi-step approach in this paper. Geometric orbits of CHAMP in 2001-2006 are precisely determined with the kinematic method only from the satellite-borne GPS zero-difference data. Then a GCM time series is estimated from the precise kinematic orbits based on the theory of satellite dynamics to fit the CHAMP's real geometric orbits. We compare the series with the geocenter series used in ITRF2005. Then the GCM series are analyzed with Fourier transform and wavelet transformation. The mean motions within 6 years in TX, TY and TZ directions are respectively 0.8 mm, 2.2 mm, and 7.9 mm. The trends of GCM in the three directions are 0.495 mm/a, -0.004 mm/a, and 1.309 mm/a, respectively. The long-term movement (2001-2006) indicates that the crustal figure is changing. The seasonal variations are the main component which may be excitated by the mass redistribution of Earth's fluid layer, e.g. ocean, atmosphere and continental water. The inter-annual variations are also found in the GCM series measured with CHAMP.

KW - CHAMP

KW - Geocenter motion

KW - Power spectral analysis

KW - Wavelet transformation

UR - http://www.scopus.com/inward/record.url?scp=51849104045&partnerID=8YFLogxK

U2 - 10.1007/s11433-008-0152-0

DO - 10.1007/s11433-008-0152-0

M3 - Article

AN - SCOPUS:51849104045

SN - 1674-7348

VL - 51

SP - 1597

EP - 1606

JO - Science China: Physics, Mechanics and Astronomy

JF - Science China: Physics, Mechanics and Astronomy

IS - 10

ER -