Part 4—Glossary

Index 1 2 3 Glossary

18. Glossary

ANEF—Australian Noise Exposure Forecast

The ANEF system was developed in the early 1980s as a tool to provide guidance on land use planning around airports. In essence, the system involves the drawing up of ANEF noise contours and the restriction of specified land uses in certain ANEF zones according to the noise sensitivity of the nominated land use. This system is similar to land use planning regimes in a number of countries.

Expanding Ways to Describe and Assess Aircraft Noise—Discussion Paper

Expanding Ways to Describe and Assess Aircraft Noise, a Discussion Paper published by DOTARS in March 2000, describes and gives the background to a number of ‘new’ aircraft noise descriptors which arose out of the public debate that followed the opening of the new runway at Sydney Airport in 1994. It is available online at

INM—Integrated Noise Model

The Integrated Noise Model is an aircraft noise modelling software package produced by the United States Federal Aviation Administration. The first version of INM was developed in the late 1970s. The INM uses aircraft operational data such as flight paths, aircraft types, runways used, etc to compute noise contours for areas surrounding airports. ANEF contours are produced directly using INM. N70 contours are derived from detailed noise grids that have been produced using INM.

NFPMS—Noise and flight path monitoring system

Integrated noise and flight path monitoring systems at airports have been introduced progressively over the past decade. These systems produce data on the location of flight paths and on the noise level of aircraft at certain noise monitoring sites around airports. The information produced by these systems is used as the basis for reporting on routine aircraft noise monitoring and underpins most of the examples of transparent noise descriptors in this document.


N70 is a term used generically to describe noise through reporting the number of aircraft noise events louder than a certain specified dB(A) level. It is also sometimes referred to as NA or Number Above. The noise level generally used in Australia is 70 dB(A) but charts showing information on the number of events louder than 60 dB(A) and 80 dB(A) are not uncommon.


Respite is a term used to report the breaks or gaps between periods of aircraft noise activity through reference to the percentage of whole hours over a specified time period, for example a day, when there have been no aircraft movements on specified flight paths.

TNIP—Transparent Noise Information Package

TNIP is a software package under development by DOTARS since late 2000. The package enables a user to rapidly interrogate aircraft activity and noise databases and to produce transparent noise descriptors. The package can be set up for any airport that has an NFPMS.

TNIP is freeware. To obtain a copy of the software, please contact the Department of Transport and Regional Services on (02) 6274 7111 or online at

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Last Updated: 9 July, 2014