diff --git a/da/ctgridded/dasystem.py b/da/ctgridded/dasystem.py
index 1f07b80939bf7462818f93b5a51ac52ca048f9b8..90634946f0b93933d6dde935b4dbe1503a153845 100755
--- a/da/ctgridded/dasystem.py
+++ b/da/ctgridded/dasystem.py
@@ -18,21 +18,49 @@ import datetime
 
 from da.baseclasses.dasystem import DaSystem
 
-class CtDaSystem(DaSystem):
+class CtGriddedDaSystem(DaSystem):
     """ Information on the data assimilation system used. This is normally an rc-file with settings.
     """
 
+    def __init__(self,rcfilename):
+        """
+        Initialization occurs from passed rc-file name, items in the rc-file will be added
+        to the dictionary
+        """
+
+        self.Identifier     = 'CarbonTracker Gridded CO2'    # the identifier gives the platform name
+
+        self.LoadRc(rcfilename)
+
+        msg  = 'Data Assimilation System initialized: %s'%self.Identifier ; logging.debug(msg)
+
+
+
     def Initialize(self):
         """ 
-        Initialize the object
+        Initialize the object. Note that we might move this module to the StateVector instead ??!
         """
         import da.tools.io4 as io
+        import numpy as np
+
+
+        mapfile         = os.path.join(self['regionsfile'])
+        ncf             = io.CT_Read(mapfile,'read')
+        self.regionmap  = ncf.GetVariable('regions')
+        dummy           = ncf.close()
+
+        msg = "Regions map on 1x1 degree was read from file %s"%self['regionsfile'] ; logging.debug(msg)
+
+        # dictionary for region <-> map conversions
 
-        mapfile   = os.path.join(self['datadir'],self['regionsfile'])
-        ncf       = io.CT_Read(mapfile,'read')
-        self.regionmap = ncf.GetVariable('budget_region')
-        dummy     = ncf.close()
+        nregions         = self.regionmap.max()
+        self.regiondict  = {}
+        for r in range(1,nregions+1):
+             sel    = (self.regionmap.flat == r).nonzero()
+             if len(sel[0])>0: 
+                 self.regiondict[r]=sel
 
+        msg = "A dictionary to map grids to states and vice versa was created" ; logging.debug(msg)
 
     def Validate(self):
         """ 
@@ -43,7 +71,6 @@ class CtDaSystem(DaSystem):
                            'obs.input.fname',
                            'ocn.covariance',
                            'nparameters',
-                           'bio.covariance',
                            'deltaco2.prefix',
                            'regtype']