Powerbot Map= Where is Home Base Charger?

Constellation

Powerbot Map= Where is Home Base Charger?

I have a Powerbot 7065 and it started creating a map after about 1 week of use.  

 

I understand that it is a crude map but I can't make any sense of the map that it created.  

 

Where is Home Base Unit?  Is there a North / South / East / West on the map?  Can someone put an "X" to mark the spot where the charger base unit is located.

 

Has anyone out there made sense of the map?