Basically they work with radars and stuff like that used for field artillery and indirect fire. The actual name of the job is Field Artillery Firefinder Radar Operator.
In the links that I have provided in the source area, you will be able to see what is exactly done by the 13R MOS. The second will also give you a little more information as to what all requirements you have to have and stuff like that.
As for being deployed to the middle east, you have just as much likelyhood of beign deployed as anyone else. You will more than likely be assigned to a regular field artillery battalion. There is no real use for a 13R in a non deploying unit, so you will be placed in a deployable unit. Unless for some reason you luck out and get stationed at the base where the school for the MOS is and get to help teach it...lol
Good luck
