Overview

The ATOP system is a key automation platform in the National Airspace System (NAS) that replaced the original oceanic air traffic control system called the Oceanic Data Processing System. It modernized the oceanic automation systems located at the Oakland, New York and Anchorage Air Route Traffic Control Centers (ARTCC). The ATOP system provides air traffic control services to aircraft flying in the 23 million square miles of airspace delegated to the United States by the International Civil Aviation Organization (ICAO) over the Atlantic, Pacific and Arctic Oceans.

The lack of terrestrial radar facilities over the oceans drives the unique ATOP concept of operations and distinguishes it from the Terminal and En Route automation platforms used domestically in the United States. It is a procedural, control-by-exception system that relies on aircraft in oceanic airspace adhering to their flight profiles or as cleared by air traffic controllers. Controller action is required only when aircraft deviate from their flight profiles.

ATOP system capabilities include:

• Integrated Flight and Surveillance Data Processing
• A Conflict Probe capability that uses a two-hour predictive horizon
• System-Maintained Electronic Flight Data
• Surveillance Processing that includes: 
  • Radar Surveillance near coastal areas
  • Automatic Dependent Surveillance – Contract (ADS-C)
  • Automatic Dependent Surveillance – Broadcast (ADS-B)
• Controller-Pilot Data Link Communications (CPDLC)
• High Frequency  Radio Operator Interface for aircraft that are not equipped for CPDLC and ADS-C
• Air Traffic Services Inter-Facility Data Communications for automated transfers of control of aircraft with adjacent international Air Navigation Service Providers
• Integrated Monitor and Control for NAS Operations Managers to monitor the state of the system at each ARTCC
• 24/7 Operations (Dual Channel Redundant Architecture)

Full operational capability of ATOP was achieved at all three ARTCCs in 2007. Since the deployment of the original system, technology refreshes were completed in 2009 and 2020 that have extended the life of the system through 2029. Another technology refresh is currently ongoing to sustain the system to support oceanic flight loads through 2039.
 
With ATOP, the FAA significantly reduced the intensive manual processes that limited the ability of controllers to safely handle airline requests for more efficient tracks or altitudes over long oceanic routes. It allows the agency to meet international commitments of reduced aircraft separation standards, thereby dramatically increasing capacity and efficiency for customers and reducing carbon emissions.

View the ATOP Storyboard for a visual representation of ATOP capabilities and operations.

In the two decades since the initial deployment of ATOP, significant enhancements to the system have continued to be implemented, reflecting the changing needs of the NAS.  These changes are summarized in the table below: 

These enhancements deliver significant benefits to stakeholders of the NAS: the flying public, commercial and civilian aircraft operators, Certified Professional Controllers, the FAA and other oversight authorities. These benefits include: 

• Optimized Flight Trajectories resulting in increased fuel efficiency and reduced operating costs for operators
• Reduced aircraft emissions, a key environmental concern
• Reduced flight durations
• Improved controller efficiency and situational awareness
• Decreased controller workload
• Enhanced system safety
• Cost efficient delivery of oceanic air traffic control services by the FAA