STATISTICAL CONSIDERATIONS IN ATMOSPHERIC DATA ASSIMILATIONRoss Bannister, Stefano MiglioriniAlan O'Neill, William Lahoz, Roger Brugge In data assimilation we must:
Some of DARC's activities:

1. How can we best assimilate data from ENVISAT? 
Observational data:Existing approach at Met Office (obsolete)Assimilate by interpolation and with fixed and diagonal .
DARC approach #1 (implemented)
Assimilate by layer averaging and with fixed and diagonal .
DARC approach #2 (planned)  S.Migliorini, C.RodgersAssimilate by averaging kernels and with full error statistics.
Retrieved state and 'truth'

Example Averaging Kernels for MIPAS OzoneIFACCNR, University of Bologna 
2. How can we use physics to better estimate uncertainties in the background fields?R.Bannister, I.Roulstone, M.Cullen, N.Nichols PressurePressure & PressureTheta ThetaPressure Covariances Horizontal windPressure Covariances

Part of the transformation between and spaces is to choose alternative parameters.
Statistics are accumulated for each parameter 