ADS-B Advanced Surveillance Enhanced Procedural Separation (ASEPS)

What it does

Improved oceanic surveillance could be the next opportunity for ADS-B coverage for the FAA. As part of a project called Advanced Surveillance Enhanced Procedural Separation (ASEPS), the FAA is analyzing and evaluating enhancements in surveillance technology that can support reduced separation between aircraft and provide safety and efficiency benefits in oceanic Flight Information Regions. This includes Space-Based ADS-B (SBA) reports and more frequent Automatic Dependent Surveillance – Contract (ADS-C) reports.

Space-Based ADS-B enables surveillance over oceanic airspace, through receivers hosted on satellites, and across the entire globe. With the SBA concept, aircraft may be tracked anywhere they fly in near real-time, increasing safety and efficiency for all users.


  • Potential for reduced separation standards in oceanic airspace
  • Improved accommodation of altitude, speed, and route change requests
  • Precise approach in non-radar airspace (specifically at small South Pacific islands)
  • Accurate and timely information for search and rescue operations
  • Harmonization across international airspace boundaries
  • Improved controller situational awareness
  • Conflict detection and resolution

How it works

The ground system would receive high update rate SBA or ADS-C surveillance reports, which could support reduced separation standards in oceanic airspace. This surveillance could be displayed on the ground system, which may be used for improved situational awareness for controllers who manage traffic procedurally in oceanic airspace.


The FAA is conducting a series of evaluations of SBA performance and benefits in oceanic and offshore airspace, as well as agency-wide use cases.

The FAA has completed a successful one-year evaluation of SBA in the Caribbean, between Florida and Puerto Rico, which yielded a valuable understanding of SBA performance in this challenging environment.

Additional evaluation work in oceanic airspace, including an evaluation at all three of the U.S. oceanic Air Traffic Control facilities (New York, Oakland, and Anchorage) will support development of the safety case, pre-operational assessments, and end-to-end system performance of SBA in FAA automation systems.

The FAA is also exploring use of non-operational SBA data in applications such as accident investigation, search and rescue, environmental impact analysis, separation analysis, commercial space, and more.

Results from these evaluations will be used to better understand the total value and benefits of SBA technology.

Last updated: Tuesday, February 7, 2023