Page - 109 - in Contributions to GRACE Gravity Field Recovery - Improvements in Dynamic Orbit Integration, Stochastic Modelling of the Antenna Offset Correction, and Co-Estimation of Satellite Orientations

2010-06-01 2010-06-08 2010-06-15 2010-06-22 2010-06-29 0.8 0.9 1.0 1.1 1.2 1.3 Old model Incl. AOC 4 6 8 10 12 (a) Arc-wise variance factors for June 2010. The shaded area indicates the period that GRACE-A spent in attitude hold mode. 2005-12-01 2005-12-08 2005-12-15 2005-12-22 2005-12-29 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Old model Incl. AOC 0 10 20 30 40 50 60 (b) Arc-wise variance factors for December 2005. The shaded area indicates the period during which GRACE-A and GRACE-B were in attitude hold mode, and where some data was lost due to a GRACE-B orbit trim manoeuvre. Figure 8.6: Ll-SST arc-wise variance factors σˆ2m for two months with periods of deteriorated data quality. (a) GRACE-A was commanded to AHM to allow investigation of a system anomaly. (b) Increased opening angles for both spacecraft during a scheduled orbit swap manoeuvre. 8.3 Results 109