one cluster topology , definition of 'barrel cell'

 One dimensional  BSMD cluster finder is insensitive to single dead strips and module boundaries for the phi strip.

However certain class of Phi-strip clusters (marked as red) are artificial split and reco as 2 phi-clusters.

One could use the Eta-strip cluster to recover from such phi-plane split if occupancy is low and relative scale of eta & phi cluster energy known.

 Plots below also introduce a concept of 'barrel cell' which has approximate size of 0.1 in eta & phi physical units and is aligned with barrel modules.  'barrel cell' is the smallest common unit in eta-phi space for SMD and BTOW tower topologies. 

'Barrel cell' has 2 coordinates : x[0,19] and y[0,59] . If such object is already defined for the Barrel,  uniform for East & West let me know and I'll adjust numbering scheme. 

Back to recovery of split phi cluster, shown below as red oval.  Green clusters are shown to 'calibrate' yourself to this type of representation.  

Fig 1.

Fig 2.