246 ATS definitions

Association of Theological Schools 
Air Traffic Services 
Air Traffic Service 
Abstract Test Suite 
Applications Technology Satellite 
across the street 
Advanced Training System 
Automatic Test System 
Administrative Terminal System 
Aircrew Training System 
American Thoracic Society 
Academic Training System 
Antarctic Treaty System 
automated trade system 
Advanced Technology Satellite 
Automated Targeting System 
Automated Trading System 
attitude transfer system 
Automated Tasking System 
Automatic Test Systems 
action tracking system 
Administrator's Tracking System 
Advanced Telecom Services 
Advanced Threat Simulator 
Allowance Tracking System 
American Trauma Society 
Apple Terminal Services 
Assignment Tracking System 
AUTO SENSE 
Auto Thrust System