FORWARD OPERATING BASE GERONIMO – Afghan Natioanl Army First Sgt. Mubarak, the operations first sergeant with 1st Kandak, 1st Brigade, 215th Corps, levels out a plot of land with Capt. Stephen Walker, the operations advisor with the Embedded Training Team, 2nd Battalion, 6th Marine Regiment, April 21, 2012. Mubarak worked with Walker to build a permanent terrain model for the Kandak. A terrain model is a 3-D map, outlining roads and other major geographical features. - FORWARD OPERATING BASE GERONIMO – Afghan Natioanl Army First Sgt. Mubarak, the operations first sergeant with 1st Kandak, 1st Brigade, 215th Corps, levels out a plot of land with Capt. Stephen Walker, the operations advisor with the Embedded Training Team, 2nd Battalion, 6th Marine Regiment, April 21, 2012. Mubarak worked with Walker to build a permanent terrain model for the Kandak. A terrain model is a 3-D map, outlining roads and other major geographical features.