What is the appropriate nav config for autonomous frontier_exploration?

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I have a robot that can successfully localize, navigate and reach goals submitted to the move_base package within the ROS Navigation stack. It's using ROS Hydro with Ubuntu 12.04 running on dual-core 1.6 GHz Intel Atom netbook, AMCL and a static map (previously created using teleop/gmapping). Now I would like to use frontier_exploration to have the robot explore autonomously. Actually, I would like it to explore completely unknown space and use gmapping to create a new static map as it explores (not utilizing a previously generated map). I believe this is a supported use case for the frontier_exploration package. Could someone confirm that?

On reading the documentation, I see that there are two options:

1. without global map
2. with global map

Regarding the global map: is that a reference to the move_base global costmap, a gmapping map, or a static map on the map server, or other? My impression is it could be any of those (but it's not clear). Is it correct?

What is the purpose of frontier_exploration if you already have a global map? If someone would explain that, it would help my understanding. However, as already stated, exploring with a pre-built static global map is not my objective here.

In setting up navigation to work with frontier_exploration, I'm faced with the issue of how to configure the navigation stack itself. I think I want to use option #1 above (unless option #2 refers to a map created on-the-fly by gmapping?), which leads me to believe I do not want to load a global map in the navigation launch file. Therefore, I would omit the following (from the move_base node launch):

<rosparam file="$(find hexapod_2dnav)/costmap_common_params.yaml" command="load" ns="global_costmap" />
<rosparam file="$(find hexapod_2dnav)/global_costmap_params.yaml" command="load" />

Beyond that, for my above described use case, I should remove the launch of AMCL and substitute it with the launch of gmapping?

Is the above correct?

Thanks very much for any advice.