Sergeant Christopher Martinez, the operations chief serving with the fire direction center with 2nd Battalion, 11th Marine Regiment, and a native of Orange County, Calif., helps members of the FDC convert target data into firing commands for the gunline during Exercise Desert Scimitar, a combined-arms, live-fire training exercise here, May 2, 2013. The FDC's job is to take the information given to them by forward observers and compute how wind, air pressure, temperature, humidity and other weather conditions will affect an artillery round while airborne.