Copernicus POD Service - Evolutions in Sentinel-3 orbit determination

Heike Peter (PosiTim UG, Germany)

CoAuthors

Javier Berzosa (GMV AD, Spain); Marc Fernández (GMV AD, Spain); Jaime Fernández (GMV AD, Spain); Pierre Féménias (ESA/ESRIN, Italy)

Event: 2020 Ocean Surface Topography Science Team Meeting (virtual)

Session: Precision Orbit Determination

Presentation type: Type Forum

The Copernicus POD (Precise Orbit Determination) Service generates precise orbital products for the Copernicus Sentinel-1, -2, and -3 missions. For Sentinel-3, these are the following products: Near Real Time (NRT), Short Time Critical (STC) and Non Time Critical (NTC). The latter two are generated as alternative for the orbit products from CNES (Centre National d’Études Spatiales).

Background models (geopotential, ocean tides and atmospheric gravity) have recently been updated and single-receiver ambiguity fixing using CODE (Center for Orbit Determination in Europe) products has been implemented for the NTC product. A significant improvement could be reached by the update of the processing setup.

Following the model updates a review of the orbit parametrization has been performed to improve the orbit results even further. The solar radiation pressure coefficient is fixed to a pre-estimated value, the number of atmospheric drag parameters is reduced and the number of empirical parameters has been increased for this purpose.

The performance of the orbit products based on the new background models, the integer ambiguity fixing and the new orbit parametrization is shown in terms of orbit time series comparisons to CNES and to other Copernicus POD QWG orbit solutions including a combined QWG orbit solution. SLR residual analysis is used to assess the absolute orbit accuracy whereas commonly estimated SLR range biases are applied to mitigate SLR related errors for the absolute orbit validation.

 
Heike Peter
PosiTim UG
Germany
heike.peter@positim.com