See dataflash2SBG on https://github.com/ENSTABretagneRobotics/File_conversions to convert ArduPilot DataFlash .log (which can be directly displayed inside Mission Planner, see the screenshots) to a .csv similar to the one that can be exported using sbgCenter for a SBG Ellipse INS.
u-center was also used to get the raw ArduSimple GPS data through USB in the .ubx.
