A GOCE only gravity model GOSG02S based on the SGG and SST observations

GOSG02S is a static gravity field model complete to spherical harmonic degree and order of 300 derived by using the Satellite Gravity Gradiometry (SGG) data and the Satellite-to-Satellite Tracking (SST) observations along the GOCE orbit based on least-squares analysis. 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, ... -- GOSG02S is a GOCE only satellite gravity model, since no priori gravity information was used in modelling procedure. 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