A proprietary algorithm that accurately measures aircraft noise exposure in the community and determines your airport’s contribution.

Using a floating threshold is a step up from fixed thresholds as it effectively varies the detection threshold based on continuously assessing background noise levels. It still requires the customer to correctly set a threshold which ANEEM doesn’t. If background levels have been high in the recent past, then a floating threshold takes time to lower the threshold level so may miss quieter aircraft noise levels. Similarly, if background levels suddenly increase, a floating threshold can take time to adapt and assigning other noise as aircraft noise. ANEEM detects when an aircraft may be causing noise and then looks to see whether it can see a peak in the noise levels that could have been generated by the aircraft. A floating threshold can also float down to very low levels that result in continuous generation of events. Effectively, meaning that whenever an aircraft is anywhere near the NMT, it can be correlated. It doesn’t offer the additional validation that ANEEM does to confirm that the noise level recorded was typical of the specific aircraft under the conditions of measurement. Where aircraft noise levels are approaching background noise levels this can lead to incorrect noise levels being assigned to aircraft movements.

No, ISO20906 does not mandate how events are generated and classified.

ISO20906 has requirements for what is included in an event. ANEEM provides the required information.

ISO20906 suggests using a threshold, minimum and maximum durations and staying below the detection level for a minimum fall time. ANEEM applies the threshold-based technique described by the standard to delineate candidate events that are evaluated.

The event delineation process is not run continuously. It is only run when aircraft are near the monitoring location. A set of candidate events are cycling through a series of threshold levels. ANEEM evaluates the candidates to determine the best fit, if any, for an aircraft event. No event is generated unless ANEEM has found a plausible aircraft event.

No, ANEEM only generates events for aircraft activity. The energy from other noise sources will be contained in the background noise measurements.

ANEEM is designed to improve the accuracy of the aircraft noise assessment. So, yes, it will change the results. The level of change will depend on how much manual grooming was being done previously and how good a monitoring location is. Depending on the environment that the monitoring is done in ANEEM may result in higher or lower levels of aircraft noise. But whichever way the data changes, aircraft noise levels will be more accurately reported with less manual grooming.

When monitoring has been done using other techniques, you may want to explain to the community why they should have more trust in the data from ANEEM. Appropriate strategies will depend on the sensitivity of the noise measurements at a location. The following engagement processes have been used:

- Use of ANEEM only at new portable monitoring locations, thus avoiding any apparent change in reported aircraft noise.

- Presenting the advantages of ANEEM versus standard event detection with examples of the improvements made. The Noise Event Workbench makes it easy to review the data for examples.

- Envirosuite has prepared comparisons at a few locations to show the advantages of ANEEM and characterise the improvements.

- External third-party report on the effectiveness of ANEEM.

- ANEEM does not produce community noise events. The community noise will be contained in the background noise levels.

The type of aircraft and what it is doing are key inputs into ANEEM. ANEEM will not function without track data. Of course, complete loss of radar data is rare. Furthermore, it should be noted that ANOMS is designed to adapt reporting to missing data. In the event of radar loss, all that is required is to flag periods that should be excluded. Envirosuite also recommends adding a suitable comment.

ANEEM will function without knowledge of the aircraft type. However, it will need to assume an aircraft type and performance will be degraded. While long periods of lost radar data are also rare, the airport may also choose to remove such periods from reporting to avoid distorting data.

ANEEM is designed for monitoring the noise levels from overflying aircraft only. It is not suitable for detecting noise from aircraft on the ground. Envirosuite has specialist algorithms that are designed for these potentially complex monitoring situations.