Reconnaissance, surveillance, and target acquisition
Reconnaissance, surveillance, and target acquisition (RSTA) squadrons are a type of unit in the United States Army. These are cavalry squadrons (though in IBCTs they typically contain at least one dismounted infantry troop), and act at the squadron (battalion) level as a reconnaissance unit for their parent brigade combat teams.
Source: Wikipedia — Reconnaissance, surveillance, and target acquisition (CC BY-SA 4.0)