Who is this article for?

Users managing segments data.

Access to the segments browser is required.

OPAS uses Selection Zones to define Operational Segments, enabling the system to track when radar points enter and exit specific areas of the airport.

1. Understanding how segments work

OPAS uses Selection Zones to define Operational Segments, leveraging existing features to enable this functionality. The system can detect when radar points enter and exit a segment, with start and end times determined by where radar tracks cross the detection zone boundaries.

The times are interpolated between the radar points before and after the track crosses the zone boundary, rounded to the nearest second. Because ground radar normally delivers data in one-second intervals, this interpolation may not always be visible. However, it becomes more apparent when gaps in radar coverage occur.

2. Planning zone configuration

While EVS engineers may complete some initial zone configuration work, a strong working knowledge of airport operations is required. Zone construction should be completed by airport staff who also demonstrate good familiarity with OPAS.

Zones become active shortly after being saved in the system and are part of the DDP system. However, the OPAS platform is processor intensive and some delays may result before you can query a new zone.

Important: A new zone will become locked shortly after saving if it is also active. This represents data sanity where users cannot alter the dimensions, invalidating previous zone analysis. Locked zones cannot be deleted. Removal or alteration of locked zones can only be performed by an EVS Support Engineer. You would need to raise a ticket explaining your requirements.

3. Creating segments

The process is straightforward. The following example shows some setup zones:

Displayed here are three Stop Bar to Runway Entrance segments and the orange Dwell at Runway Entrance. Having access to the satellite or aerial map layer is extremely useful.

By placing a new zone under the correct Selection Zone folder name, OPAS will detect and analyse operations that pass through the zones, as long as they are labelled correctly.