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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 
  • ATS 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.   

ATOP monthly report: The topics for this month’s ATOP program update will focus on ATOP Site operational progress and the ATOP T28 release  

All Sites are up and operating on T27, which was the tech refresh 2 (TR2) build. There are three capabilities in T28 that relate to TR2 but for all purposes, TR2 has been successfully deployed at all 3 ATOP Sites.  

Anchorage Center (ZAN) has been able to deploy T28. Due to impacts of COVID, New York Center (ZNY) and Oakland (ZOA) have not deployed T28. Below is the Site operational progress to date and T28 enhancement and capabilities. 

ATOP Site Operational Progress 

  • ZOA has been operational on T27 TR2 Linux system since 1/23/20 (Initial Operations)  

– No plans in place yet for step-up to T2801  

– ZOA set up a second CWP in the OMIC area (NOM Position) to allow them to have an area to control traffic while the control room is being cleaned  

  • ZAN has been operational on T2801 since 12/16/20  

– No plans in place yet for step-up to T2802  

– TR2 cable remediation activity still needs to occur – schedule is TBD 

  • ZNY has been operational on T27 TR2 since 10/7/19 (Initial Operations) Stepped up to T2703002 patch on 2/11/21 – No plans yet to step-up to T2801. 

 – New York ARTCC ATOP Radar Project Request • Site requesting to add 16 Radars and one ADS-B station 

 – Near term goal is to get 8 radars & one ADS-B station added • Plan for Miami to add a Longport for remaining Radars not currently available via IP 

ATOP T28 Release 

  • T28 TR2 Content: 

      − Issue 52358 – TR2-11: Performance Enhancements  

− Issue 52359 – ZTC: TR2-12: SAR Enhancements  

− Issue 53586 – Longport serial port does not failover to redundant PCM serial port  

  • T28 Enhancements 1 (E1) Content  

− Issue 52196 – ZNY: Feedback message when trying to apply 3 or D flags is incorrect  

  • T28 Oceanic Improvements (OI) Content  

− Issue 50667 – ZNY: False coordination data is discrepant message when aircraft coordinated inbound climbing 

 − Issue 50996 – ZOA: Add ATCC to HOLD message 

 − Issue 51207 – NCP:  AFN Window Needs Redesign 

 − Issue 53842 – ZTC: Unnecessary SQUAWK uplinked to non-data link aircraft leaving radar-controlled airspace 

 − Issue 56111 – Unable to input SIGMET Whiskey 1 – airspace reservations limit  

  • Ops Content 

 − Issue 58200 – ZAN: Apply Wheat / White Alternating colors for PCMs 

ATOP T29 Operational Evaluation: ATOP T29 is ready for the Site evaluation. The evaluation includes all three operational sites and is conducted at the Technical Center. Because of COVID travel restrictions the proposed week of March 22nd is cancelled with a new proposed date of the week of May 17th.  

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

*Future of the Ocean 2035 (FOTO 2035) 

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

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

All three Oceanic Sites are still working under the 5/5 COVID mitigation schedule. I want to thank the Site leads and SME’s for being on all the necessary meetings and providing the comments and inputs needed 5 days a week while juggling their schedules.  

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 


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