2026-08-10T07:29:53Zhttp://doidb.wdc-terra.org/oaip/oai
oai:doidb.wdc-terra.org:77862026-06-10T10:24:37ZDOIDBDOIDB.ICGEM
false4DOIDB.ICGEM 10.5880/icgem.2023.003 Zhao, Yongqi Yongqi Zhao 0000-0002-3484-950X School of Geodesy and Geomatics, Wuhan University, Wuhan, China Li, Jiancheng Jiancheng Li School of Geodesy and Geomatics, Wuhan University, Wuhan, China Xu, Xinyu Xinyu Xu 0000-0003-1614-1900 School of Geodesy and Geomatics, Wuhan University, Wuhan, China Su, Yong Yong Su 0000-0003-1067-7712 School of Civil Engineering and Geomatics, Southwest Petroleum University, Chengdu, China WHU-SWPU-GOGR2022S: A combined gravity model of GOCE and GRACE GFZ Data Services 2023 WHU-SWPU-GOGR2022S GOCE GRACE ICGEM global gravity field model geodesy Zhao, Yongqi Yongqi Zhao 0000-0002-3484-950X School of Geodesy and Geomatics, Wuhan University, Wuhan, China Zhao, Yongqi Yongqi Zhao 0000-0002-3484-950X School of Geodesy and Geomatics, Wuhan University, Wuhan, China Li, Jiancheng Jiancheng Li School of Geodesy and Geomatics, Wuhan University, Wuhan, China Xu, Xinyu Xinyu Xu 0000-0003-1614-1900 School of Geodesy and Geomatics, Wuhan University, Wuhan, China Su, Yong Yong Su 0000-0003-1067-7712 School of Civil Engineering and Geomatics, Southwest Petroleum University, Chengdu, China Zhao, Yongqi School of Geodesy and Geomatics, Wuhan University, Wuhan, China Model http://www.geophy.cn//article/doi/10.6038/cjg2022Q0615 http://icgem.gfz-potsdam.de/ CC BY 4.0 WHU-SWPU-GOGR2022S is a static gravity field model complete to spherical harmonic degree and order of 300 by combining GOCE and GRACE normal equations. Details of the processing procedures are as follows:

(1) Details of the GOCE processing procedures:
(1a) Input data:
-- GOCE SGG data: EGG_NOM_2 (GGT: Vxx, Vyy, Vzz and Vxz) in GRF (9/10/2009-20/10/2013)
-- GOCE SST data: SST_PKI_2, SST_PCV_2, SST_PRD_2 (9/10/2009-20/10/2013)
-- Attitude: EGG_NOM_2 (IAQ), SST_PRM_2 (PRM)
-- Non-conservative force: Common mode ACC (GG_CCD_1i)
-- Background model: tidal model (solid etc.), third-body acceleration, relativistic corrections, ...

(1b) Data progress strategies:
-- Data preprocessing
- Gross outlier elimination and interpolation (only for the data gaps less than 40s).
- Splitting data into subsections for gaps > 40s

-- The normal equation from SST data
- Point-wise acceleration approach (PAA)
- Extended Differentiation Filter (low-pass)
- Max degree: up to 130
- Data: PKI, PCV, CCD

-- The normal equation from SGG data
- Direct LS method
- Max degree: up to 300
- Data: GGT, PRD, IAQ, PRM
- Band-pass filter: used to deal with colored-noise of GGT observations (pass band 0.005-0.100Hz )
- Forming the normal equations according to subsections
- Spherical harmonic base function transformation instead of transforming GGT from GRF to LNRF

-- Combination of SGG and SST
- Max degree: up to 300
- The VCE technique is used to estimate the relative weights for Vxx, Vyy, Vzz and Vxz
- Tikhonov Regularization Technique (TRT) is only applied to near (zonal) terms (m<20, n<=200) and high degree terms (n>200)
- Strictly inverse the normal matrix based on OpenMP


(2) Details of the GRACE processing procedures:

(2a) Input data:
-- GRACE L1B (JPL) data products: GNV1B RL02, ACC1B RL02, SCA1B RL03 and KBR1B RL03
-- AOD1B RL06 (GFZ) de-aliasing product
-- Data period: 04/2002-05/2017

(2b) Data preprocessing:
-- Splitting data of SCA1B into subsections for gaps > 120s and interpolation with polynomial for gaps <= 120s
-- Splitting data of ACC1B into subsections for gaps > 5s and interpolation with polynomial for gaps <= 5s
-- Gross outlier elimination ACC1B with a moving window of length 10 min, and interpolation with polynomial
-- Pre-calibration of ACC1B with a-priori bias and scale Parameters provided by GRACE TN-02

(2c) Calculation method:
- dynamic approach
- numerical integrator: 8th-order Gauss-Jackson integrator
- integrator step: 5 seconds
- arc length: 24 hours

(2d) Combination
- GNV1B and KBR1B are combined with their a-priori precision, i.e. 2cm of GNV1B and 2um/s of KBR1B
- The normal equations of different months are combined with variance components estimation

(2e) Force models:
- Earth's static gravity field: GGM05s up to d/o 180
- Solid earth tides: IERS 2010
- Ocean tides: FES2014b up to d/o 180
- Solid Earth pole tide: IERS 2010
- Ocean pole tide: Desai 2002 up to d/o 180
- N-body Perturbation: the Sun and Moon with JPL DE421
- atmospheric tides: Bode and Biancale model
- AOD1B product: AOD1B RL06 model up to d/o 180
- General Relativistic effects: Schwarzschild terms of IERS 2010

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