Abstract's details

Introduction of 2/rev harmonics in the empirical forces model for Sentinel altimetry satellites

Georgia Katsigianni (CLS, France)


Flavien Mercier (CNES, France); Alexandre Couhert (CNES, France); John Moyard (CNES, France)

Event: 2023 Ocean Surface Topography Science Team Meeting

Session: Precision Orbit Determination

Presentation type: Type Forum only

Contribution: PDF file


Accurate modelling of the empirical forces is a key element for altimetry Precise Orbit Determination (POD). Hill’s equations are widely used for perturbed satellite circular orbits. However, traditionally the empirical forces are estimated at the revolution period once per revolution (1/rev).

As shown by Mercier et al. (2022), a spectral analysis of the radial displacement harmonics for Sentinel-6 showed a twice per revolution (2/rev) main harmonic due to the Solar Radiation Pressure (SRP) force. The 2/rev harmonic effects due to Albedo or Infrared radiation (IR) were negligible. Furthermore, during satellite eclipse transitions the 2/rev contributions were more important. That analysis concluded the need to investigate further the improvement of the current empirical forces model.

In this study we, the altimetry POD team of CNES, apply an extra term for estimating the 2/rev harmonics with the goal to analyze possible improvements in the orbit radial direction residuals by examining Satellite Laser Ranging (SLR) measurements. Our investigation focuses mainly on Sentinel satellites using the operational ZOOM POD software of CNES. We compare the current operational modeling (POE-F standards) of the empirical forces to the adjusted modeling with the 2/rev component.

Mercier F., Couhert A., Moyard J., Cullen R. (2022) « Sentinel-6 radiation pressure model analysis », OSTST 2022, Venice, Italy, DOI: 10.24400/527896/a03-2022.3517, https://ostst.aviso.altimetry.fr/fileadmin/user_upload/OSTST2022/Presentations/POD2022-Sentinel_6_radiation_pressure_model_analysis.pdf

Georgia Katsigianni