Noise monitoring

Constant monitoring of aircraft noise in the vicinity of the airport is a legal requirement. Under Section 19a of the German Air Traffic Act (LuftVG), airport operators are required to set up and continuously operate equipment to measure the noise levels of inbound and outbound aircraft at their airports and in surrounding areas. In particular, operators are required to monitor the development of aircraft noise by performing long-term measurements and to check the effectiveness of the noise reduction measures that have been implemented.

The aircraft noise monitoring system at Dresden International Airport was upgraded in November 2017.

The new system consists of four stationary measuring stations located at sites in the vicinity of the airport. The sites were chosen jointly with the Aircraft Noise Commission for Dresden Airport, taking into account the requirements of DIN 45643-2011 “Measurement and assessment of aircraft sound”. Sites that had proven their worth over many years were retained and a new measuring site was installed at Dresden Neustadt Clinic. The measuring stations are optimally placed to ensure that high-quality readings are obtained, in other words:

  1. close to the published approach and departure procedures in order to register as many noise events caused by overflying aircraft as possible
  2. in the vicinity of residential districts in order to correctly reflect the impact on residents;
  3. avoiding extraneous noise such as road or rail traffic as far as possible.

More about noise monitoring

Steffen Mäder

Head of Noise/Environmental Protection

Telefonnummer

+49 (0)351 881-3020

Faxnummer

+49 (0)351 881-3024

Locations of noise measuring stations

 

Measuring station 1: Städtisches Klinikum Dresden (Dresden City Clinic); Industriestraße 40, 01129 Dresden-Pieschen
Measuring station 2: Gomlitzer Höhe 13; 01108 Dresden-Weixdorf
Measuring station 3: Medinger Straße 12, 01458 Ottendorf-Okrilla; OT Hermsdorf
Measuring station 4: Grüne Aue 45, 01109 Dresden-Rähnitz

Measurement results

When the aircraft noise monitoring system was upgraded in November 2017, we switched to monthly reports. These reports (German only) contain the measurements from all four measuring sites.

December 2017 monthly report  [PDF; 762 KB]

January 2018 monthly report  [PDF; 745 KB]

February 2018 monthly report  [PDF; 731 KB]

March 2018 monthly report  [PDF; 1,2 MB]

April 2018 monthly report  [PDF, 726 kB]

May 2018 monthly report  [PDF, 2,0 MB]

June 2018 monthly report [PDF-Datei, 2,3 MB]

July 2018 monthly report [PDF, 740 kB]

August 2018 monthly report [PDF, 740 kB]

September 2018 monthly report[PDF, 2 MB]

The analyses from the previous measuring stations from 2014 to 2017 can be found here:

Monitoring point 1: Dresden-Hellerau water tower, Brunnenweg
Monitoring point 2: Primary School 84, Heinrich-Tessenow-Weg, Dresden-Hellerau
Monitoring point 3: Residential building, Medinger Straße 12, Hermsdorf
Monitoring point 4: Residential building, Grüne Aue 45, Dresden-Rähnitz
Monitoring point 5: Obstruction lights pylon on the airport grounds, Dresden-Weixdorf

Noise monitoring point

How noise is monitored

Measurements are taken continuously at all measuring stations and  recorded for every second. Aircraft noise events are identified with the help of a graphical display of periodic measurements and aircraft noise identification parameters which can be configured to suit the location  of the monitoring equipment and the acoustic conditions prevailing there (background noise, other noise sources). Other noise sources such as  vehicular and rail traffic or birds can be filtered out with the aid of  the parameters and by checking the audio recordings.

The measurements from the previous day are forwarded once a day to the central data processing unit where they are matched to aircraft movements, so that each aircraft noise event is correlated with a certain aircraft movement. This correlation process is performed with a time slot model which enables the time at which the aircraft overflies the measuring site to be determined based on the actual aircraft take-off or landing times registered in the airport’s flight log and the approach and departure speeds of the various types of aircraft (jet aircraft, propeller aircraft, helicopters). Noise events which meet the aircraft noise identification parameters and which were recorded close to the calculated theoretical overflying time can thus be matched automatically and precisely to a specific flight.

Since the noise measurements could potentially be distorted by high wind speeds which cause significant sound pressure levels on the microphone, the aircraft noise events recorded in these conditions are not taken into account in the statistical analyses. This also applies in cases in which very loud noises from other sources mask the aircraft noise, preventing accurate measurement of the aircraft noise. Corresponding meteorological data is available from the METAR system and is also measured at measuring station 1 simultaneously with the aircraft noise events.

After final manual testing and correlation of each individual aircraft noise event, the acoustic parameters, such as the continuous sound level, are calculated and stored for subsequent analyses, together with all the acoustic and meteorological measurements and parameters.
 In addition to general aircraft noise monitoring, this quality-assured data forms the basis for reporting to the Aircraft Noise Commission and for publication on Dresden Airport’s website, as well as for responding to complaints about aircraft noise.

Single event and continuous sound level

Two variables are used as a benchmark for assessing aircraft noise levels: the single event sound level LAmax and the continuous sound level LAeq, both expressed in dB(A).

The single event sound level LAmax describes the maximum sound pressure level of an individual noise event, e.g. when a single aircraft passes overhead or nearby. The continuous sound level LAeq (often also referred to as the average sound level) identifies noise levels varying over time with just one number. In the continuous sound level, the strength and duration of each individual noise during a certain evaluation period are disproportionately high as they are logarithmic values.

The equivalent continuous sound levels LAeq,day and LAeq,night are therefore used as the basis for assessing aircraft noise. The diurnal assessment period is from 06:00 to 22:00 and the nocturnal period is from 22:00 to 06:00.

High-precision measuring equipment

We only use quality class 1 measuring equipment (the highest quality) as only these permit DIN-compliant measurements. To ensure the proper operation of our aircraft noise monitoring equipment, every measuring station is checked daily and acoustically calibrated at six-monthly intervals.

All measuring equipment used to monitor aircraft noise is tested and serviced every two years to ensure that it is fully functional and subsequently calibrated and verified. This repeated comparison of setpoint and actual values against a standardised comparison source is the only way to guarantee that the measurements are taken with the highest precision.

Checking the measurements at a noise monitoring point

Sound level reference values

Very faint noises in a range between 0 and 20 dB can actually only be  measured in sound-proofed labs, because ordinary ambient noise will  always exceed these levels. Even the "absolute silence" of the remotest  place outdoors produces noise levels of between 20 and 30 dB. A standard A filter is installed in the monitoring equipment to make allowance for the varying sensitivity of human hearing to high and low sounds. The  unit of measurement is thus referred to as dB(A).

The following rule of thumb is used to express the correlation between the measured sound pressure level and the distance to the source of the noise: Tripling the distance reduces the sound pressure level by 10 dB and thus halves the perceived noise nuisance.


Type of noiseSound pressure level
Hearing threshold 0 dB(A)
Breathing noise (at a distance of about 1 m) 25 dB(A)
Very quiet room 20-30 dB(A)
Ticking alarm clock 30-35 dB(A)
Rustling leaves 30-40 dB(A)
Whispering 40 dB(A)
Normal conversation (at a distance of about 1 m) 50-60 dB(A)
DA 20 Katana aircraft (2-seater, 0.7 t MTOW), passing at an altitude of 300 m 60 dB(A)
TV at room volume (at a distance of about 1 m) 55-60 dB(A)
Shouting 70 dB(A)
Car (at a distance of about 10 m) 60-80 dB(A)
ATR 42 aircraft (up to 50 seats, 16 t MTOW) during take-off, at a distance of about 300 m 75 dB(A)
AVRO RJ aircraft (up to 112 seats, 44 t MTOW) during take-off, at a distance of about 300 m 80 dB(A)
Main road (at a distance of about 10 m) 80-85 dB(A)
Airbus A320 aircraft (up to 180 seats, 74 t MTOW) during take-off, at a distance of about 300 m 85 dB(A)
Pneumatic drill at a distance of 1 m or heavy truck at a distance of 5 m 90 dB(A)
Boeing B747-400 aircraft (up to 524 seats, 386 t MTOW) during take-off, at a distance of about 300 m 90 dB(A)
Night club 110-120 dB(A)
Car horn at a distance of a few metres 110 dB(A)
Pain threshold um 130 dB(A)

MTOW = Maximum Take-Off-Weight