We Guide You Home


John T. Lenhart (ZOA) is the Article 114 Representative for Advanced Technologies & Oceanic Procedures (ATOP).   

ATOP Program  

Background:  The ATOP system processes information consistent with system calculations or expectations (e.g. vertical movement) and provides alerts to controllers when a situation arises or information is received that is out of conformance and/or requires attention or action. This “control by exception” concept has enabled oceanic air traffic operations to advance to a level that would not have been possible under the previous manual system. The ATOP system is anticipated to have the capability and maintainability to meet the future demands posed by new airborne technologies and the associated procedures. 

The ATOP system concept incorporates existing and emerging technologies into a single, integrated system.   

These technologies include:  

  • Flight profile monitoring, utilizing flight data processing and surveillance data processing based on data from the following sources: 

o  Automatic Dependent Surveillance – Broadcast (ADS-B) 

o  Primary and secondary radar 

o  Automatic Dependent Surveillance – Contract (ADS-C FANS-1/A compatible) 

o  Controller-Pilot Data Link Communications (CPDLC) position reports 

o  High Frequency (HF) radio position reports 

  • CPDLC, (FANS-1/A compatible)
  • Air Traffic Services (ATS)  Inter-Facility Data Communications (AIDC) 
  • NAS Interfacility message set
  • Facilities Notifications (AFN) (FANS-1/A compatible) Conflict detection, prediction, and alerting (radar separation and non-radar oceanic separation) 
  • Workload monitor 

The ATOP system manages long-term conflicts (up to two hours), operational requirements (e.g. coordination, workload monitoring), and aircraft requests.  The ATOP program consists of an ATOP Program Manager, NATCA National Lead, NATCA Site Leads, and operational area Subject Matter Experts (SME’s) as well as Oceanic Airspace Managers from each Site. We also have representation from AJV-I, AJT, Site Techs, ATOP Second Level Engineering, and ATOP Contract Support.   

 In last month’s ATOP review I reported the program was working on ATOP Enhancement 2 (E2). This month there was significant work that concentrated around ATOP E2 candidates. Several meetings took place going through possible candidates as well as ensuring the correct Line of Business (LOB) requester, description and rational was documented for each item. ATOP E2 items are long term initiatives that normally revolve around future technology and capabilities. It is not too late to add to the E2 candidate list. As always, you can contact me personally if you would like to discuss adding candidates or have questions or inputs on items in the current preliminary list. Below is the preliminary ATOP E2 list: 

Background:   The following potential ATOP E2 candidates have been identified by an ATOP sub-team composed of AJV-I, AJT, AJM-21, and NATCA.  The list is considered preliminary, and will likely be modified in the future, and requires additional prioritization inputs.  The expected deployment of the ATOP changes would be via four yearly releases from 2025 to 2028. 

  1. Sat Voice Integration at Controller Workstation 
  • LOB Requester:  AJV-I 
  • Description:  ATOP Workstation CHI integration of SAT Voice.  
  • Rationale:  Sat Voice is a maturing communications capability that should align with the schedule of ATOP E2.  The Concept of Operations is yet to be established, but at a minimum would be available for emergency and urgent communications via an approximate 20 second connection time verses a communication patch through ARINC. 
  1. Provide Reroute Options for THAs/Wx 
  • LOB Requester:  AJV-I 
  • Description: Create ATOP algorithm with logic for conflict resolution options beyond altitude.  The change is not for probe results but reroutes for a THA or weather (i.e., possibly speed or route). 
  • Rationale:  This would provide controllers with efficient, accurate and approved re-route options around activated airspace like Military, volcanic ash, WX SIGMETS, THAs, etc.  Currently reservations are manually entered and to avoid airspace the controller enters point at a large scale that may “work” but may not be efficient. It also negatively impacts controller and pilot work load. 
  1. More Frequent Wind Forecasts to Support Improved Aircraft Profiles 
  • LOB Requester:  AJV-I 
  • Description: Incorporate into ATOP more frequent wind forecasts (i.e., every hour instead of every 6 hours) that will be available in 2024. 
  • Rationale:  More frequent wind forecasts will increase the accuracy of aircraft profiles and thus the accuracy of conflict prediction. 
  1. Target-to-Target Separation Standard 
  • LOB Requester:  AJV-I 
  • Description:  Implement CHI and conflict probe changes to support future ICAO-approved target-to-target separation. 
  • Rationale:  Increased reporting rates/capabilities and improved communications is anticipated to lead to some level of target-target separation in the oceanic environment.   
  1. Improved Weather (Wx) Deviations 
  • LOB Requester:  AJV-I 
  • Description:  Implement changes in ATOP to address cases where distance-based longitudinal separation during Wx deviations is not supported by the T30 Wx NCP. 
  • Rationale:  It is expected that further adjustments and developments to the implemented weather deviation solution will be needed/desired. 
  1. Improved Resilience Capabilities and Features 
  • LOB Requester:  AJV-I 
  • Description:  Additional changes to ATOP to support improved failure mode capabilities beyond the changes planned for ATOP E1 (e.g., ATOP in box). 
  • Rationale:  No current capabilities are satisfactory for safety or efficiency.  The team discussed potential remote and remote-portable solutions.  The team also discussed changes and enhancements to the current system state like a separate application to keep flight data and information even after both channels were lost. 
  1. AIDC 3.0 
  • LOB Requester:  AJV-I 
  • Description: Upgrade AIDC to PANS 1.0 (AIDC 3.0). 
  • Rationale:  AIDC PANS 1.0 (AIDC 3.0) is the current and latest AIDC standard and will be incorporated by an increasing number of adjacent FIRs.  ATOP will implement this to enhance harmonization and ensure as much flight data as possible can be communicated automatically. 
  • LOB Requester:  NextGen and AJM-25 
  • Description:  Ingest WARP via SWIM (Graphical Wx for ZAN and potentially ZNY and ZOA).   
  • Rationale:  The current interface that provides the weather model to ATOP is being discontinued in the future and moving to SWIM.  This will ensure the weather model continues to be available to the system and complete the CSS-Wx business case. 
  • LOB Requester:  NextGen and AJM-25 
  • Description:  Ingest WINS data (winds aloft) via SWIM and support more frequent wind models.   
  • Rationale:  The current interface that provides the WINS data to ATOP is being discontinued in the future and moving to SWIM.  This will ensure the WINS data continues to be available to the system, support more frequent forecast model for improved profile accuracy, and complete the CSS-Wx business case. 
  1. SWIM: Flight Data Publish 
  • LOB Requester:  NextGen and AJM-25 
  • Description:  Publish ATOP flight data via SWIM. 
  • Rationale:  The infrastructure improvement will be needed for AIDC and other automated flight data exchanges in the future.  The change also supports easier and standardized access to ATOP data for analyses and research & development. 
  1. Properly Disseminate Hazardous Inflight Weather Advisory’s in accordance with FAA Order: 7110.65, 2-6-6 
  • LOB Requester:  ZNY 
  • Description:  Change to ATOP to provide a window to process and disseminate hazards due to the unique nature and formatting of Hazardous Inflight Weather Advisories. 
  • Rationale:  ATOP has the ability to automatically disseminate SIGMET and PIREP information to affected flights.  However, other information regarding potentially hazardous inflight weather, such as Center Weather Advisories, are not included and thus not disseminated.  This is not in conformance with FAA Order 7110.65 2-6-6.  
  1. Track Generation Algorithm utilizing SUA/THA information 
  • LOB Requester:  AJV-I 
  • Description: Change to ATOP to create a track generation algorithm utilizing SUA/THA information available to the ATOP system. 
  • Rationale:  SUA and THA information can change, causing the need to modify aircraft routes either around airspace that has activated or utilize airspace that had been active but since became inactive unexpectedly.  In addition, THAs have specific geometries for routes to pass through safely.  Currently, track generation is done using the DOTS+ system.  That system is end-of-life, has not kept up with current aircraft models, and can only be used with Traffic Management is staffed, which may not coincide with when the latest weather or airspace changes are received.  Incorporating these functions into ATOP would take advantage of the ATOP wind, weather, and airspace activity information and allow tracks to be generated whenever this information changes. 

This Month the ATOP Program has worked collaboratively with the following Programs/Projects: 

Future of the Ocean 2035 (FOTO 2035) 

FOTO 2035 Core Team has completed the gap analysis this month and is now moving on to the program’s smart goals. The smart goals are designed to pave a way forward concept realities.   

Acceptable Level of Risk (ALR) National Lead, Paul Behan 

No Change: The ALR project has went through reorganization. The new direction is to break off into subgroups. Transition Hazard Area’s (THA’s) in the Oceanic environment will include the ATOP program working closely with the ALR team to achieve solutions.  

Spaced Based ADS-B (SBA) National Lead, Dan Hamilton 

Work continues to concentrate around the three SBA Site projects. MITRE has been assisting the three Oceanic sites to complete the development of the SBA conops. ZNY is now scheduled for their conops meeting Oct. 13, 2020. 

As always, if anyone would like additional information on any ATOP subject, issue or would like to receive more technical explanations, feel free to contact me at any time. Controllers at the Oceanic Sites can also reach out to the Site Leads and SME’s. Any inputs, ideas, and feedback are always welcome from the sites. Contact your site leads if you have enhancement or improvement ideas. Below is the contact information for the NATCA ATOP Cadre and Site leads:  

BUR: JT Lenhart ATOP National Lead 


ZNY: John Fox , ZNY Lead, OCA West (WATRS) SME 


         Todd Tourin, North Atlantic SME 


ZAN: Mark Crabtree, ZAN Lead, SME 


ZOA: Donald White, ZOA Lead, Pacific North SME 


         Catherine Siu, ZOA Pacific South SME 


Jump to top of page