You will find the generic routines for the EnKF in:

Analysis/            Contains routines for computing the EnKF analysis.
                     

                     Other utilitaries:

                     mod_states.F90        definition of a state (Hycom)
                     mod_dimensions.F90    grid dimensions 
                     m_read_ensemble.F90   I/O to binary files
                     m_write_ensemble.F90  

Sampling/            Routines for simulation of 1D and 2D pseduo random fields.

Sampling.old/        Old version of Sampling.

Programming_example/   a tutorial for Geir's programming style
                       plus a collection of makefiles for different platforms
                       (at the moment only IBM under AIX ...)

NERSC_implementation/  For the lazy dude: all of the EnKF code used at NERSC
                       ... rather oceanography and HYCOM-oriented.

Oldpseudo2D          Contains the old code for generation of 1D random curves
                     and 2D random fields.
                     It uses the Numerical_Recipes code for FFT routines

Loc_paper_Matlab_code Matlab code for the paper : Pavel Sakov and Laurent 
                     Bertino "Relation between two common localisation methods 
                     for the EnKF", submitted to Computational Geosciences.