Radar Track Analysis for Aircraft Noise Calculation

To protect the population adequately from health impairments caused by aircraft noise, aircraft noise protection areas are often published at commercial airports. The calculation of these noise protection zones (e.g. according to the ECAC Doc 29 method) is based on airport information and flight routes as GIS-based input as well as flight movement numbers and aircraft types for the forecast period, information on flight times and the distribution of operating directions. Aside from the flight procedures set out in the Aeronautical Information Publication (AIP), deviations from official flight procedures in practice can also be taken into account when determining noise protection zones. The identification of these deviations is facilitated by the analysis of radar tracks. 

The deviation from published IFR flight procedures by means of so-called "directs" (direct clearances of air traffic control) is often the subject of discussions between residents in the vicinity of airports, air traffic control, airlines, airport operators and aviation authorities. Direct clearances are granted by air traffic control on a case-by-case basis for reasons of capacity, efficiency, safety aspects or meteorological conditions. The consideration of this "flight operational practice" is of great importance for the calculation of the noise protection zones, as it incorporates the real flight behaviour of the aircraft on the way to/from the airport in the noise calculation. Consequently, the resulting aircraft noise contour would be based less on the published procedures and more on the actual flown aircraft tracks around an airport. 

^{Image Description: Red - Departure radar tracks, Turquoise - Resulting backbone from radar track analysis, Blue - Flight track corridors}

When modelling the flight routes as a preparatory process step for the calculation of the noise protection zones, the key question arises as to where the approach and departure routes of aircraft are located. Various sources of information can be used for this purpose:  

• The AIP contains information on the published IFR flight procedures at the respective airport with waypoints, minimum altitudes, flight speeds, etc. 

• Radar data (e.g. Flight course data based on Flight Track and Aircraft Noise Monitoring System – FANOMOS or ADS-B data) contain the real flight paths of individual flight movements that may deviate from the official flight procedures according to AIP due to direct clearances by means of radar vectoring (lateral clearances from air traffic control ) or direct routing (approval of the shortest route to the next navigation point by air traffic control). 

airsight therefore analyses the radar data as follows: 

• Comparison of the real track according to radar data with AIP flight procedures 

• Determination of flight corridors according to statistical analysis methods to consider the real dispersion of individual radar tracks along the flight path (lateral and vertical) 

• Further statistical analyses on runway use, operating direction distribution, aircraft types and validation with flight plan data.  

The findings of the radar data analysis gained in this way serve as a basis for determining the flight routes as essential input for the aircraft noise calculation. More information on that matter can be found in our article Data input acquistion and aircraft noise calculation for planning approval process.

^{Image Description: Example overlay radar tracks vs. AIP routes}

airsight offers services regarding aircraft noise assessments, including data analysis, modelling and calculation of aircraft noise contours and noise protection zones in accordance with applicable law for airport operators, authorities and air navigation service providers. By overlaying the contours with census data and using empirical-based dose-response functions (e.g. as defined in WHO Environmental noise guidelines for the European Region) we are able to predict the noise impact on the population (e.g. rate of highly annoyed people).

If you would like to learn more about airsight's services related to aircraft noise, please visit our "Sustainable Aviation" page. We look forward to receiving your e-mail about any aircraft noise-related questions you would like to discuss with us!