Fig. 9 Swarm C along-track acceleration during a satellite maneuver for scale factor calibration on May 11 , 2015
We review here only those disturbances that are important for the processing of along-track acceleration of Swarm C: sudden bias changes referred to as steps, slow temperature-induced bias variations referred to as temperature sensitivity, acceleration spikes due to thruster activations, and Error Detection And Correction (EDAC) failure events.
The number of spikes in Swarm C along-track accelerations is fortunately not high.
Fig. 1 Representative example of a step in raw along-track accelerations of Swarm C on July 4 , 2014
Fig. 6 Result of step correction of along-track accelerations of Swarm C in the period from June 1 , 2014 to May 31 , 2015
Fig. 3 Representative example of a thruster spike in raw along-track accelerations of Swarm C on July 4 , 2014
Fig. 5 Corrected steps in along-track accelerations of Swarm C in the period from June 1 , 2014 to May 31 , 2015
Though the changes in characteristics are much smaller for the along-track accelerations compared to the cross-track and nadir accelerations, it is reasonable to assume that also the parameters for the along-track accelerations have to be exchanged at the epoch of the abrupt change.
Furthermore, we investigate the effect of empirical cross-track accelerations and the effect of relativistic accelerations of near-Earth satellites on ΔLO D
The blue lines show calibrated and corrected along-track accelerations, the red lines show the latter with an additional 31-s moving-median filter applied, and the black lines show the accelerations from POD.
Since our efforts to correct for steps in an automated way provided unsatisfying results so far, we corrected steps in along-track accelerations of Swarm C manually for the period from June 1 , 2014 to May 31 , 2015 using a dedicated software tool.
