To become a Warrant Officer in the US Army you have to have five years military experience in a Military Occupational Speciality (MOS) that feeds the Warrant MOS you are going into. For a Targeting Technician that is most Field Artillery MOS. Then you have to submit a packet, which is reviewed by a board to determine your elegibility. Lastly you have to have a senior Warrant Officer in the field write a letter of recommendation.