Combination at the Observation Level - IERS

Combination at the NEq level vs. observation level∑i– with the same software handling several techniques– with different software packages if they are well homogenizedcalc n calc∂Q⎛ Q⎞i ⎜∂ipjQ ⎟i= 0 ∀k= ,np∑ ∆ − ∆∂k j p1⎝ = 1 ∂j ⎠NEQ levelObservation levelConsistent processing of the data using the same models and parameterization∆Q= Q− QcalciAppropriate relative weighting of the techniquesCorrections to the original observations are estimatedOutlier detection and weighting ofobservations technique-wiseA priori reduced parameter cannot behandled anymoreiobsi=n∑j=1∂Q∂pij∆pOutlier detection and weighting ofobservations within the combinationprocessAll parameters are availableSeitz, Thaller - Workshop on Combination on Observation Level, 21./22.10.09, WarsawOnly technique dependent parameters can be reduced for an actualequivalence between NEq level and observation levelj