Abstract
An analysis of current static and time-variable gravity field models is presented focusing on the medium to high frequencies of the geopotential as expressed by the spherical harmonic coefficients. A validation scheme of the gravity field models is implemented based on dynamic orbit determination that is applied in a degree-wise cumulative sense of the individual spherical harmonics. The approach is applied to real data of the Gravity Field and Steady-State Ocean Circulation (GOCE) and Gravity Recovery and Climate Experiment (GRACE) satellite missions, as well as to GRACE inter-satellite K-band ranging (KBR) data. Since the proposed scheme aims at capturing gravitational discrepancies, we consider a few deterministic empirical parameters in order to avoid absorbing part of the gravity signal that may be included in the monitored orbit residuals. The present contribution aims at a band-limited analysis for identifying characteristic degree ranges and thresholds of the various GRACE- and GOCE-based gravity field models. The degree range 100–180 is investigated based on the degree-wise cumulative approach. The identified degree thresholds have values of 130 and 160 based on the GRACE KBR data and the GOCE orbit analysis, respectively.
Highlights
Orbit determination is a core topic in satellite geodesy, comprising both geometrical and dynamical aspects in the pursuit of constructing a detailed mathematical model that can describe the motion of an artificial satellite orbiting Earth as accurately as possible [1]
The validation scheme of the gravity field models is implemented here based on a dynamic orbit determination algorithm that is applied in a degree-wise cumulative sense of the individual spherical harmonics
The current study provides an assessment of gravity field models and presents a relative validation between them
Summary
Orbit determination is a core topic in satellite geodesy, comprising both geometrical and dynamical aspects in the pursuit of constructing a detailed mathematical model that can describe the motion of an artificial satellite orbiting Earth as accurately as possible [1]. With the advent of a vast number of new satellite-only and combined gravity field models, the main bulk of which are routinely produced from the analysis of currently available satellite data, the problem of orbit determination, especially its dynamic counterpart, received an abundance of solutions for the numerical computation of Earth’s gravitational attraction at satellite altitude. An additional insight to the computation of the equation of motion is envisaged, while at the same time an independent possibility is offered to model and validate highly precise satellite data, such as Gravity Recovery and Climate Experiment (GRACE)-like inter-satellite ranges and range rates. The validation scheme of the gravity field models is implemented here based on a dynamic orbit determination algorithm that is applied in a degree-wise cumulative sense of the individual spherical harmonics.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
