Hello all,

I am working on slam_gmapping tutorial "How to build a Map using logged 
data".
I have a case like,
A Robot while building its own map initially; if it comes across the 
location where there are downstairs and so it will not find any boundary 
line to draw. In such case what would be the cell occupancy?
Will it be treated as "-1 completely unknown"? 
If so then, according to 'LRF readings method' it should be completely 
'undecided area' and has to be treated always as an obstacle in future map 
updates.
Also, while initial mapping, do we require encoder reading (==distance 
travelled) to match with the laser input?

Looking forward for your help.

-Prasad Dixit