GRACE-A and GRACE-B together

Conclusions
• 1-2 cm kinematic positioning for LEO satellites and IGS stations &
10 cm for GPS satellites is possible.
• Kinematic POD can be used as an interface for determination of gravity field
parameters and other phenomenon that govern the satellite motion.
• 30-s GPS satellite clocks can be estimated with the full normal equation matrix using 40
IGS stations. Positioning with the relative phase clocks has been successfuly performed.
• 90%-100% of all ambiguities can be resolved for GRACE baseline using Melbourne-
Wübbena wide-lanning with narrow-lane bootstrapping.
• After ambiguity resolution kinematic and reduced-dynamic baseline results agree on
the level of 1 cm and 3 mm respectively when validated with KBR measurements.
• Combined processing of zero- and double-differences changes the orbit by 1-2 cm
compared to zero-diff. case and is the optimal strategy for the LEO formation flying.
• KBR and ambiguity resolution clearly shows colored noise in the kinematic positions
and defficienties in the dynamic modelling.
• KBR has very strong impact on the kinematic and reduced-dynamic GPS baseline
even when the ambiguities are fixed.
FGS Workshop 2004, Höllenstein/Wettzell, October 27 - 29, 2004