Who is this article for?

ANOMS administrators who need to adjust noise-to-track correlation settings for a monitor.

Focus access with management rights is required — granted per site; contact Ideagen support if you do not have access.

Correlation parameters control how far from a noise monitor an aircraft can be for its flight track to be matched to a noise event.

Finding the correlation parameters

Note: These steps are performed in Focus, the noise monitor management web tool. Focus access with management rights is granted per site — contact Ideagen support if you do not have access.

To access the correlation parameters:

1. Go to Customer Setup.
2. Select NMT Manager.
3. Select the site.
4. Open Active Locations.
5. Select the NMT.
6. Click Manage.

Note: Menu names and paths may vary slightly between Focus versions.

The Correlation Parameters section is towards the bottom of the page. It contains the Correlation Max Distance (in metres) and Correlation Max Altitude (in metres above the NMT elevation), which together define the cylinder around the monitor within which aircraft are considered for matching.

The ANOMS Correlation Parameters section on the monitor management page, with Correlation Max Distance and Correlation Max Altitude fields

Sizing guidance

As a rule, correlation parameters should be set smaller the closer the monitor is to the runway. As monitors are placed further from the runway and from approach and departure paths, the parameters should be logically extended, based on analysis in ANOMS.

Mapping operations and reviewing their proximity to the monitors is the best way to determine sensible correlation distances. A monitor next to the runway requires minimal settings, whereas a monitor some distance from the runway may need a large cylinder defined to capture good potential matches.

Set your expectations accordingly: some aircraft will not be assigned noise events (especially light aircraft, or at distant NMTs), and some events allocated to aircraft will turn out not to be aircraft noise.

For the methodology behind choosing and refining these values, see the published article on tuning noise-to-track matching parameters.