I have been trying to find clear resources to help me learn how exactly frontier exploration works:

[i] How are new cells(obstaacles,free space,added) added to the updateing occupancygrid map and how does this affect how the occupancy grid probability array is created.

[ii] Does this affect the position of the origin as the map gets bigger?

[iii] How are the map co-ordinates stored?

[iv] How does is the goal to move to chosen?

I've looked at the explore_lite ROS wiki and these things seem to be kinda glossed over but not explained in full detail.