Community Noise Monitoring Saffron Walden
Community Noise Monitoring Saffron Walden
John Campbell – Campbell Associates Ltd
Saffron Walden Community Noise Monitoring
Contents Page Number
1.0
Overview
2
2.0
Defining Aircraft Noise
4
3.0
Flights Arrivals and Departures
6
4.0
Number of Noise Events
7
4.1 Number of aircraft events per hour
8
4.2 Aircraft Noise Events by Aircraft Type
9
Maximum noise levels
10
5.1 Maximum levels by aircraft type
10
5.2 Maximum levels by day
11
5.3 Maximum levels by hour of the day
12
Noise Climate
14
6.1 LAeq average and L90 background noise
14
6.2 Average noise, Aircraft Noise and Residual noise
15
6.3 Lden values
16
Summary and Conclusions
17
5.0
6.0
7.0
Appendix 1 - Aircraft Type by IATA Code
18
Appendix 2 - Gate Penetration Graphs
21 1
Saffron Walden Community Noise Monitoring
Community Noise Monitoring Saffron Walden
1.0
Overview
Campbell Associates were commissioned by London Stansted Airport to undertake three months community noise monitoring to evaluate the impact of noise from Aircraft from Stansted Airport and provide a baseline for future noise monitoring. The monitoring dates were the 1st of November 2011 to the 27th of January 2012 The noise monitor was situated in Bridge End Gardens, See figure 1 where the yellow pin mark identifies the location
2
Saffron Walden Community Noise Monitoring
The instrumentation conforming to IEC 61672 type one was fixed to a maintenance hut in the corner of the formal gardens and the measurement microphone extended on a pole above the roof. See figure 2. The noise monitor was located approximately 14.6km from London Stansted airport. See figure 3
Figure 2 Measurement Microphone position
Figure 3 Measurement location 3
Saffron Walden Community Noise Monitoring
2.0
Defining Aircraft Noise
To establish the noise impact of aircraft on the community the noise from Aircraft needs to be separated from other noise. To do this the sound level data collected over the three month period was analyzed to find patterns in the data, which could be attributed to aircraft noise. To do this a threshold level of 53dBA and a time period of 8 seconds was set. Any noise data which fits this criterion was identified and labeled as a ‘Noise Event’. The next stage was to attribute the noise event to individual aircraft arriving at, or departing from London Stansted Airport. To do this a gate was defined (which can be seen in figure 4) and all Aircraft which pass through the gate were identified by Aircraft type, flight number and with a date and time stamp. With the date and time stamp it is possible to correlate a noise event to an aircraft to give us ‘Aircraft Noise Events’.
Figure 4 – Gate to identify aircraft overflying Saffron Walden
4
Saffron Walden Community Noise Monitoring
The table in figure 5 below shows the number of noise events, aircraft noise events, flights in flight plan passing over Saffron Walden and the correlation rate.
Total noise events
11513
Aircraft Noise events
1593
Flights in flight plan
2905
Correlation rate
55%
Figure 5 – Correlation of Aircraft Noise Events
A Correlation rate of 55% is an acceptable rate for this monitoring project when the distance from the airport is taken into account. Measurements where noise monitors are closer to an airport will give greater correlation. This is because the sound level of the aircraft is greater as they are flying lower over the noise monitor. This makes them much easier to identify above other sounds in the vicinity of the noise monitor. The sound level from aircraft overflying Saffron Walden on some days, especially when there was high wind, was too close to background noise to be able to identify as aircraft noise events. Please note the study only includes Aircraft flying to, or departing from London Stansted. Flights to and from other airports are not included.
5
Saffron Walden Community Noise Monitoring
3.0
Flight Arrivals and Departures
During the measurement period the vast majority of movements over Saffron Walden were arrivals. The breakdown is as follows with flight plan being the total movement and aircraft events being those that could be identified as noise events: Flight Plan •
Flight arrivals – 2878
•
Flight departures - 27
Aircraft events
6
•
Flight arrivals – 1,593
•
Flight departures – 14
Saffron Walden Community Noise Monitoring
4.0
Number of Noise Events
The chart in figure 6 shows the number of aircraft noise events per day. From the graph it can be seen that the number of events varies significantly from day to day. This is mostly due to runway usage but also due to efficiency of the correlation of aircraft noise events. On some days it was not possible to correlate noise events due to weather conditions generating high background noise levels.
Figure 6: Numbers of Noise events
Numbers of Noise events each day
50
40
30
20
10
0
7
Saffron Walden Community Noise Monitoring
4.1 Number of Aircraft events per hour Figure 7 shows the distribution of Aircraft per hour of the day. The aircraft events mainly start at 7am which is associated with arrivals at the Airport. We can see from Arrivals and departures in section 3.0 that arrivals are far more frequent in relation to Saffron Walden.
Figure 7: Number of Aircraft Events per hour
Number of Noise events during each hour
160 140 120 100 80 60 40 20 0 0
1
2
3
4
5
6
7
8
9
10
11
12
13
Hour of Day
8
14
15
16
17
18
19
20
21
22
23
Saffron Walden Community Noise Monitoring
4.2
Aircraft Noise Events by Aircraft Type
Figure 8 shows the distribution of events by aircraft type. The majority of aircraft are types 73H (Boeing 737-800) and 319 (Airbus 319). The Boeing 737-800 and Airbus 319 are the aircraft types used by Ryanair and Easyjet respectively and are two of the major carriers operating from London Stansted.
Figure 8: Numbers of Aircraft noise events from different Aircraft types 1000 900
700 600 500 400 300 200 100 0
73H 319 733 M1F AT7 320 73Y 74N ER3 76Y 74Y ABY CNJ 752 738 73W 77x SWM CCJ E90 142 AR8 D38 DF7 GS5 321 762 76X APF CCX EM2 GRJ GS4 744 763 75W AB6 ANF CL6 DF3 E70 EP3 F50 L45 L60 LOH LTJ M83 P12 PA2
number of Events
800
Aircraft type codes
9
Saffron Walden Community Noise Monitoring
5.0
Maximum noise levels
During the measurement period the noise monitor also recorded the maximum sound levels. For Aircraft monitoring this is measured with A weighting and a slow network and is referred to as the LAS max 5.1 Maximum levels by aircraft type For each Aircraft noise event this maximum level is also reported which can be seen in Figure 9 below by aircraft type. The maximum levels range from 56dB to 68.2dB LAS max and the most commonly used aircraft 73H and 319 had an average of maximum levels of 61.8dB and 62.1dB LAS max respectively.
Figure 9: Average value of maximum noise level arising from different Aircraft types 80
Noise level / LAS max dB
70 60 50
40 30
20
0
74N ANF LOH GS5 762 77x AB6 74Y 752 CCJ F50 L45 142 M1F EM2 319 73H GRJ 76X 320 ER3 744 738 APF 73W ABY AT7 AR8 321 P12 76Y CCX 73Y 733 D38 E90 E70 CNJ CL6 EP3 DF7 PA2 SWM GS4 DF3 L60 M83 LTJ 75W 763
10
Aircraft type codes
10
Saffron Walden Community Noise Monitoring
5.2
Maximum levels by day
Figure 10 below shows the average of the maximum levels by day of the monitoring period. Gaps in data were due to poor weather where aircraft noise events could not be identified.
Figure 10: Average value of maximum noise levels of aircraft noise events 68 66 64 Noise level / LAS max dB
62
60 58 56 54 52 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 65 67 69 71 73 75 77 79 81 83 85
Day of measurement
11
Saffron Walden Community Noise Monitoring
5.3
Maximum levels by hour of the day
Figure 11 shows the spread of maximum noise levels by hour of the day.
Figure 11: Average value of maximum noise levels of aircraft noise event per hour of day
Noise level / LAS max dB
64 63 62 61 60 59 58 57 56 0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 hours of day
Please note the maximum noise levels are mostly dictated by the path of the aircraft and how closely they overflew the noise monitor. The gate which can be seen from figure 4 shows that the aircraft can be some distance from the monitor. The maximum levels measured in this exercise should not be used as a means of establishing the noisiest aircraft.
12
Saffron Walden Community Noise Monitoring
Figure 12 displays the distribution of maximum aircraft noise events.
Figure 12 : Statistical distribution of maximum noise levels of aircraft noise 250
Number of Events
200
150
100
50
0 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 Noise level / LASmax dB
13
Saffron Walden Community Noise Monitoring
6.0
Noise Climate
6.1
LAeq average and L90 background noise
Figure 13 displays the noise climate at the monitoring location displayed by hour of the day. This includes all noise for the complete monitoring period. It is expressed as an Leq value which is the energetic average of all sound over each hourly period. In addition there is an LA90 value plotted which is a statistical calculation on the sound levels logged. The LA90 is the noise level which is exceeded for 90% of the time and is a value which is commonly used as an indicator for background noise at a given location.
Figure 13: Noise climate total noise (Leq) and background noise (LA90) hour by hour 60
Noise level / dBA
55 50
LAeq 45
LA90 40 35 30 25 20 0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20 21 22 23
Hour of Day
14
Saffron Walden Community Noise Monitoring
6.2 Average noise, Aircraft Noise and Residual noise Figure 14 displays the average (LAeq) levels by hour again but also displays the level attributed to aircraft noise by hour. This is calculated by combining the aircraft noise events during the monitoring period. This value is then subtracted from the total noise to give a residual noise which is the level you would expect if the aircraft noise events are removed.
Figure 14: Noise Climate showing average values for each hour of total noise, aircraft noise and residual noise (LAeq) Hour of Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Aircraft Noise 36.7 36.8 37.4 37.8 39.4 43.0 44.7 46.5 46.4 48.0 48.9 47.2 47.4 47.7 45.8 45.2 44.8 45.3 46.5 46.6 44.0 41.7 41.5 37.8
Total Noise 42.9 42.5 43.5 44.6 45.8 48.8 50.5 51.7 52.3 52.4 53.1 51.6 52.0 53.0 51.2 51.1 50.2 49.8 50.4 51.1 50.0 47.5 46.0 43.6
Residual Noise 41.7 41.2 42.3 43.6 44.7 47.5 49.2 50.1 51.0 50.4 51.0 49.6 50.1 51.4 49.7 49.7 48.7 47.9 48.2 49.2 48.7 46.1 44.1 42.3
15
Saffron Walden Community Noise Monitoring
6.3 Lden values The table in figure 14 below shows the levels as expressed as an Lden value. The Lden is a noise metric which is a 24 hour average (LAeq) normally calculated for an annual period. It includes a 5 dB weighting for evening and a 10 dB weighting for night periods. The periods are broken down as can be seen in table 14. The Lden is an indicator which is being increasingly used as an expression of the long term noise climate at a given location. This has been expressed in the table below for total noise, aircraft noise and residual noise.
Total Noise – Lden 54.3 dB Day 07.00 -19.00
= 51.8dB(A)
Evening 19.00-23.00 = 49.3dB(A) Night 23.00 – 07.00 = 46.4dB(A) Aircraft Noise – Lden 48.5 dB Day 07.00 -19.00
= 46.8dB(A)
Evening 19.00-23.00
= 44.0dB(A)
Night 23.00 – 07.00 = 39.9dB(A) Residual Noise – Lden 53.8 dB Day 07.00 -19.00
= 50.2dB(A)
Evening 19.00-23.00
= 47.8dB(A)
Night 23.00 – 07.00 = 45.3dB(A) Figure 14 – Lden values
16
Saffron Walden Community Noise Monitoring
7.0
Summary and Conclusions
The community noise monitoring has been a useful exercise to establish:
The impact of aircraft noise from London Stansted Airport on Saffron Walden It is possible to measure aircraft noise in Saffron Walden and correlate this with aircraft associated to Stansted Airport. A baseline, which can be used for any future noise monitoring in the Saffron Walden community.
17
Saffron Walden Community Noise Monitoring
Appendix 1 Aircraft Type by IATA Code IATA Code 73H 319 AT7 733 DH4 73Y M1F 320 74Y ER3 CNJ 142 74N ABY 738
ICAO Code
GRJ
n/a
76Y GS5 CCJ E90 73W 76X AR8 CCX CL6 DF3 77X
B763
Manufacturer and aircraft type/ model
B738
Boeing 737-800 (winglets) pax
A319
Airbus A319
AT72
Aerospatiale/Alenia ATR 72
B733
Boeing 737-300 pax
DH8D
De Havilland Canada DHC-8-400 Dash 8Q
B733
Boeing 737-300 Freighter
MD11
McDonnell Douglas MD11 Freighter
A320
Airbus A320-100/200
B744
Boeing 747-400 Freighter
E135
Embraer RJ135
n/a
Cessna Citation
B462
BAe 146-200 Pax 747 - 800 (Freighter)
A306
Airbus Industrie A600-600 Freighter
B738
Boeing 737-800 pax Gulfstream Aerospace G-1159 Gulfstream II / III / IV / V Boeing 767-300 Freighter Gulfstream 5
CL60
Canadair Challenger
E190
Embraer 190
B737
Boeing 737-700 (winglets) pax
B762
Boeing 767-200 Freighter
RJ85
Avro RJ85 Avroliner
GLEX
Canadair Global Express Challenger 604/605
DC3
Douglas DC-3 Freighter
B762
DF2
n/a
752 EM2 GS4
B752
Boeing 767-200 Freighter Dassault (Breguet Mystere) Falcon 10 / 100 / 20 / 200 / 2000 Boeing 757-200 pax
E120
Embraer EMB.120 Brasilia
GLF4
SWM
n/a
Gulfstream 4 Fairchild (Swearingen) SA26 / SA226 / SA227 Metro / Merlin / Expediter
14Z H25 LRJ 763 D38 E70 EP1 318 321 73C CJT CN7
B463
18
BAe 146 Freighter (-200QT & QC)
n/a
British Aerospace (Hawker Siddeley) HS.125
n/a
Gates Learjet
B763
Boeing 767-300 pax
D328
Fairchild Dornier Do.328
E170
Embraer 170 Embraer Phenom 100
A318
Airbus A318
A321
Airbus A321-100/200 737-300 (Winglets) Cessna Jet Cessna Citation 750x
Saffron Walden Community Noise Monitoring
F50 L45 L60 PA2 722 735 73G 74L 75W APF CCL CJ2 FRJ P12 SFF 332 63M 744 762 A4F AR1 BE2 CGX CXL DA5 DAF DF7 ER4 ERJ F27 G20 GS2 GS3 LOF LOH M83 PR1
F50
Fokker 50 Learjet 45 Learjet 60
n/a
Piper light aircraft - twin piston engines
B722
Boeing 727-200 pax
B735
Boeing 737-500 pax
B737
Boeing 737-700 pax
N74S
Boeing 747SP 757-200 (Winglets) ATP - freighter Challenger 600 Series Cesna citation CJ2
J328
Fairchild Dornier 328JET Pilatus PC-12 SAAB 340 Freighter
A332
Airbus A330-200 Boeing globemaster 3
B744
Boeing 747-400 pax
B762
Boeing 767-200 pax
A124
Antonov AN-124 Ruslan
RJ1H
Avro RJ100 Avroliner
n/a
Beechcraft twin piston engines Global Express Falcon 50 Dassant Falcon (Generic) Falcon 7x
E145
Embraer RJ145 Amazon
n/a
Embraer RJ135 / RJ140 / RJ145
F27
Fokker F.27 Friendship / Fairchild F.27 Gulfstream galaxy 200 Gulfstream 2 Gulfstream 3
L188
Lockheed L-188 Electra Freighter
C130
Lockheed L-182 / 282 / 382 (L-100) Hercules
MD83
McDonnell Douglas MD83 Premier 1
19
Saffron Walden Community Noise Monitoring
Appendix 2 Gate Penetration Graphs for Saffron Walden 04 and 22 Departures (all 3 months)
04 and 22 Arrivals November 2011
20
Saffron Walden Community Noise Monitoring
04 and 22 Arrivals December 2011
04 and 22 Arrivals January 2012
21
John Campbell – Campbell Associates Ltd
Saffron Walden Community Noise Monitoring
Contents Page Number
1.0
Overview
2
2.0
Defining Aircraft Noise
4
3.0
Flights Arrivals and Departures
6
4.0
Number of Noise Events
7
4.1 Number of aircraft events per hour
8
4.2 Aircraft Noise Events by Aircraft Type
9
Maximum noise levels
10
5.1 Maximum levels by aircraft type
10
5.2 Maximum levels by day
11
5.3 Maximum levels by hour of the day
12
Noise Climate
14
6.1 LAeq average and L90 background noise
14
6.2 Average noise, Aircraft Noise and Residual noise
15
6.3 Lden values
16
Summary and Conclusions
17
5.0
6.0
7.0
Appendix 1 - Aircraft Type by IATA Code
18
Appendix 2 - Gate Penetration Graphs
21 1
Saffron Walden Community Noise Monitoring
Community Noise Monitoring Saffron Walden
1.0
Overview
Campbell Associates were commissioned by London Stansted Airport to undertake three months community noise monitoring to evaluate the impact of noise from Aircraft from Stansted Airport and provide a baseline for future noise monitoring. The monitoring dates were the 1st of November 2011 to the 27th of January 2012 The noise monitor was situated in Bridge End Gardens, See figure 1 where the yellow pin mark identifies the location
2
Saffron Walden Community Noise Monitoring
The instrumentation conforming to IEC 61672 type one was fixed to a maintenance hut in the corner of the formal gardens and the measurement microphone extended on a pole above the roof. See figure 2. The noise monitor was located approximately 14.6km from London Stansted airport. See figure 3
Figure 2 Measurement Microphone position
Figure 3 Measurement location 3
Saffron Walden Community Noise Monitoring
2.0
Defining Aircraft Noise
To establish the noise impact of aircraft on the community the noise from Aircraft needs to be separated from other noise. To do this the sound level data collected over the three month period was analyzed to find patterns in the data, which could be attributed to aircraft noise. To do this a threshold level of 53dBA and a time period of 8 seconds was set. Any noise data which fits this criterion was identified and labeled as a ‘Noise Event’. The next stage was to attribute the noise event to individual aircraft arriving at, or departing from London Stansted Airport. To do this a gate was defined (which can be seen in figure 4) and all Aircraft which pass through the gate were identified by Aircraft type, flight number and with a date and time stamp. With the date and time stamp it is possible to correlate a noise event to an aircraft to give us ‘Aircraft Noise Events’.
Figure 4 – Gate to identify aircraft overflying Saffron Walden
4
Saffron Walden Community Noise Monitoring
The table in figure 5 below shows the number of noise events, aircraft noise events, flights in flight plan passing over Saffron Walden and the correlation rate.
Total noise events
11513
Aircraft Noise events
1593
Flights in flight plan
2905
Correlation rate
55%
Figure 5 – Correlation of Aircraft Noise Events
A Correlation rate of 55% is an acceptable rate for this monitoring project when the distance from the airport is taken into account. Measurements where noise monitors are closer to an airport will give greater correlation. This is because the sound level of the aircraft is greater as they are flying lower over the noise monitor. This makes them much easier to identify above other sounds in the vicinity of the noise monitor. The sound level from aircraft overflying Saffron Walden on some days, especially when there was high wind, was too close to background noise to be able to identify as aircraft noise events. Please note the study only includes Aircraft flying to, or departing from London Stansted. Flights to and from other airports are not included.
5
Saffron Walden Community Noise Monitoring
3.0
Flight Arrivals and Departures
During the measurement period the vast majority of movements over Saffron Walden were arrivals. The breakdown is as follows with flight plan being the total movement and aircraft events being those that could be identified as noise events: Flight Plan •
Flight arrivals – 2878
•
Flight departures - 27
Aircraft events
6
•
Flight arrivals – 1,593
•
Flight departures – 14
Saffron Walden Community Noise Monitoring
4.0
Number of Noise Events
The chart in figure 6 shows the number of aircraft noise events per day. From the graph it can be seen that the number of events varies significantly from day to day. This is mostly due to runway usage but also due to efficiency of the correlation of aircraft noise events. On some days it was not possible to correlate noise events due to weather conditions generating high background noise levels.
Figure 6: Numbers of Noise events
Numbers of Noise events each day
50
40
30
20
10
0
7
Saffron Walden Community Noise Monitoring
4.1 Number of Aircraft events per hour Figure 7 shows the distribution of Aircraft per hour of the day. The aircraft events mainly start at 7am which is associated with arrivals at the Airport. We can see from Arrivals and departures in section 3.0 that arrivals are far more frequent in relation to Saffron Walden.
Figure 7: Number of Aircraft Events per hour
Number of Noise events during each hour
160 140 120 100 80 60 40 20 0 0
1
2
3
4
5
6
7
8
9
10
11
12
13
Hour of Day
8
14
15
16
17
18
19
20
21
22
23
Saffron Walden Community Noise Monitoring
4.2
Aircraft Noise Events by Aircraft Type
Figure 8 shows the distribution of events by aircraft type. The majority of aircraft are types 73H (Boeing 737-800) and 319 (Airbus 319). The Boeing 737-800 and Airbus 319 are the aircraft types used by Ryanair and Easyjet respectively and are two of the major carriers operating from London Stansted.
Figure 8: Numbers of Aircraft noise events from different Aircraft types 1000 900
700 600 500 400 300 200 100 0
73H 319 733 M1F AT7 320 73Y 74N ER3 76Y 74Y ABY CNJ 752 738 73W 77x SWM CCJ E90 142 AR8 D38 DF7 GS5 321 762 76X APF CCX EM2 GRJ GS4 744 763 75W AB6 ANF CL6 DF3 E70 EP3 F50 L45 L60 LOH LTJ M83 P12 PA2
number of Events
800
Aircraft type codes
9
Saffron Walden Community Noise Monitoring
5.0
Maximum noise levels
During the measurement period the noise monitor also recorded the maximum sound levels. For Aircraft monitoring this is measured with A weighting and a slow network and is referred to as the LAS max 5.1 Maximum levels by aircraft type For each Aircraft noise event this maximum level is also reported which can be seen in Figure 9 below by aircraft type. The maximum levels range from 56dB to 68.2dB LAS max and the most commonly used aircraft 73H and 319 had an average of maximum levels of 61.8dB and 62.1dB LAS max respectively.
Figure 9: Average value of maximum noise level arising from different Aircraft types 80
Noise level / LAS max dB
70 60 50
40 30
20
0
74N ANF LOH GS5 762 77x AB6 74Y 752 CCJ F50 L45 142 M1F EM2 319 73H GRJ 76X 320 ER3 744 738 APF 73W ABY AT7 AR8 321 P12 76Y CCX 73Y 733 D38 E90 E70 CNJ CL6 EP3 DF7 PA2 SWM GS4 DF3 L60 M83 LTJ 75W 763
10
Aircraft type codes
10
Saffron Walden Community Noise Monitoring
5.2
Maximum levels by day
Figure 10 below shows the average of the maximum levels by day of the monitoring period. Gaps in data were due to poor weather where aircraft noise events could not be identified.
Figure 10: Average value of maximum noise levels of aircraft noise events 68 66 64 Noise level / LAS max dB
62
60 58 56 54 52 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 65 67 69 71 73 75 77 79 81 83 85
Day of measurement
11
Saffron Walden Community Noise Monitoring
5.3
Maximum levels by hour of the day
Figure 11 shows the spread of maximum noise levels by hour of the day.
Figure 11: Average value of maximum noise levels of aircraft noise event per hour of day
Noise level / LAS max dB
64 63 62 61 60 59 58 57 56 0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 hours of day
Please note the maximum noise levels are mostly dictated by the path of the aircraft and how closely they overflew the noise monitor. The gate which can be seen from figure 4 shows that the aircraft can be some distance from the monitor. The maximum levels measured in this exercise should not be used as a means of establishing the noisiest aircraft.
12
Saffron Walden Community Noise Monitoring
Figure 12 displays the distribution of maximum aircraft noise events.
Figure 12 : Statistical distribution of maximum noise levels of aircraft noise 250
Number of Events
200
150
100
50
0 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 Noise level / LASmax dB
13
Saffron Walden Community Noise Monitoring
6.0
Noise Climate
6.1
LAeq average and L90 background noise
Figure 13 displays the noise climate at the monitoring location displayed by hour of the day. This includes all noise for the complete monitoring period. It is expressed as an Leq value which is the energetic average of all sound over each hourly period. In addition there is an LA90 value plotted which is a statistical calculation on the sound levels logged. The LA90 is the noise level which is exceeded for 90% of the time and is a value which is commonly used as an indicator for background noise at a given location.
Figure 13: Noise climate total noise (Leq) and background noise (LA90) hour by hour 60
Noise level / dBA
55 50
LAeq 45
LA90 40 35 30 25 20 0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20 21 22 23
Hour of Day
14
Saffron Walden Community Noise Monitoring
6.2 Average noise, Aircraft Noise and Residual noise Figure 14 displays the average (LAeq) levels by hour again but also displays the level attributed to aircraft noise by hour. This is calculated by combining the aircraft noise events during the monitoring period. This value is then subtracted from the total noise to give a residual noise which is the level you would expect if the aircraft noise events are removed.
Figure 14: Noise Climate showing average values for each hour of total noise, aircraft noise and residual noise (LAeq) Hour of Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Aircraft Noise 36.7 36.8 37.4 37.8 39.4 43.0 44.7 46.5 46.4 48.0 48.9 47.2 47.4 47.7 45.8 45.2 44.8 45.3 46.5 46.6 44.0 41.7 41.5 37.8
Total Noise 42.9 42.5 43.5 44.6 45.8 48.8 50.5 51.7 52.3 52.4 53.1 51.6 52.0 53.0 51.2 51.1 50.2 49.8 50.4 51.1 50.0 47.5 46.0 43.6
Residual Noise 41.7 41.2 42.3 43.6 44.7 47.5 49.2 50.1 51.0 50.4 51.0 49.6 50.1 51.4 49.7 49.7 48.7 47.9 48.2 49.2 48.7 46.1 44.1 42.3
15
Saffron Walden Community Noise Monitoring
6.3 Lden values The table in figure 14 below shows the levels as expressed as an Lden value. The Lden is a noise metric which is a 24 hour average (LAeq) normally calculated for an annual period. It includes a 5 dB weighting for evening and a 10 dB weighting for night periods. The periods are broken down as can be seen in table 14. The Lden is an indicator which is being increasingly used as an expression of the long term noise climate at a given location. This has been expressed in the table below for total noise, aircraft noise and residual noise.
Total Noise – Lden 54.3 dB Day 07.00 -19.00
= 51.8dB(A)
Evening 19.00-23.00 = 49.3dB(A) Night 23.00 – 07.00 = 46.4dB(A) Aircraft Noise – Lden 48.5 dB Day 07.00 -19.00
= 46.8dB(A)
Evening 19.00-23.00
= 44.0dB(A)
Night 23.00 – 07.00 = 39.9dB(A) Residual Noise – Lden 53.8 dB Day 07.00 -19.00
= 50.2dB(A)
Evening 19.00-23.00
= 47.8dB(A)
Night 23.00 – 07.00 = 45.3dB(A) Figure 14 – Lden values
16
Saffron Walden Community Noise Monitoring
7.0
Summary and Conclusions
The community noise monitoring has been a useful exercise to establish:
The impact of aircraft noise from London Stansted Airport on Saffron Walden It is possible to measure aircraft noise in Saffron Walden and correlate this with aircraft associated to Stansted Airport. A baseline, which can be used for any future noise monitoring in the Saffron Walden community.
17
Saffron Walden Community Noise Monitoring
Appendix 1 Aircraft Type by IATA Code IATA Code 73H 319 AT7 733 DH4 73Y M1F 320 74Y ER3 CNJ 142 74N ABY 738
ICAO Code
GRJ
n/a
76Y GS5 CCJ E90 73W 76X AR8 CCX CL6 DF3 77X
B763
Manufacturer and aircraft type/ model
B738
Boeing 737-800 (winglets) pax
A319
Airbus A319
AT72
Aerospatiale/Alenia ATR 72
B733
Boeing 737-300 pax
DH8D
De Havilland Canada DHC-8-400 Dash 8Q
B733
Boeing 737-300 Freighter
MD11
McDonnell Douglas MD11 Freighter
A320
Airbus A320-100/200
B744
Boeing 747-400 Freighter
E135
Embraer RJ135
n/a
Cessna Citation
B462
BAe 146-200 Pax 747 - 800 (Freighter)
A306
Airbus Industrie A600-600 Freighter
B738
Boeing 737-800 pax Gulfstream Aerospace G-1159 Gulfstream II / III / IV / V Boeing 767-300 Freighter Gulfstream 5
CL60
Canadair Challenger
E190
Embraer 190
B737
Boeing 737-700 (winglets) pax
B762
Boeing 767-200 Freighter
RJ85
Avro RJ85 Avroliner
GLEX
Canadair Global Express Challenger 604/605
DC3
Douglas DC-3 Freighter
B762
DF2
n/a
752 EM2 GS4
B752
Boeing 767-200 Freighter Dassault (Breguet Mystere) Falcon 10 / 100 / 20 / 200 / 2000 Boeing 757-200 pax
E120
Embraer EMB.120 Brasilia
GLF4
SWM
n/a
Gulfstream 4 Fairchild (Swearingen) SA26 / SA226 / SA227 Metro / Merlin / Expediter
14Z H25 LRJ 763 D38 E70 EP1 318 321 73C CJT CN7
B463
18
BAe 146 Freighter (-200QT & QC)
n/a
British Aerospace (Hawker Siddeley) HS.125
n/a
Gates Learjet
B763
Boeing 767-300 pax
D328
Fairchild Dornier Do.328
E170
Embraer 170 Embraer Phenom 100
A318
Airbus A318
A321
Airbus A321-100/200 737-300 (Winglets) Cessna Jet Cessna Citation 750x
Saffron Walden Community Noise Monitoring
F50 L45 L60 PA2 722 735 73G 74L 75W APF CCL CJ2 FRJ P12 SFF 332 63M 744 762 A4F AR1 BE2 CGX CXL DA5 DAF DF7 ER4 ERJ F27 G20 GS2 GS3 LOF LOH M83 PR1
F50
Fokker 50 Learjet 45 Learjet 60
n/a
Piper light aircraft - twin piston engines
B722
Boeing 727-200 pax
B735
Boeing 737-500 pax
B737
Boeing 737-700 pax
N74S
Boeing 747SP 757-200 (Winglets) ATP - freighter Challenger 600 Series Cesna citation CJ2
J328
Fairchild Dornier 328JET Pilatus PC-12 SAAB 340 Freighter
A332
Airbus A330-200 Boeing globemaster 3
B744
Boeing 747-400 pax
B762
Boeing 767-200 pax
A124
Antonov AN-124 Ruslan
RJ1H
Avro RJ100 Avroliner
n/a
Beechcraft twin piston engines Global Express Falcon 50 Dassant Falcon (Generic) Falcon 7x
E145
Embraer RJ145 Amazon
n/a
Embraer RJ135 / RJ140 / RJ145
F27
Fokker F.27 Friendship / Fairchild F.27 Gulfstream galaxy 200 Gulfstream 2 Gulfstream 3
L188
Lockheed L-188 Electra Freighter
C130
Lockheed L-182 / 282 / 382 (L-100) Hercules
MD83
McDonnell Douglas MD83 Premier 1
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Saffron Walden Community Noise Monitoring
Appendix 2 Gate Penetration Graphs for Saffron Walden 04 and 22 Departures (all 3 months)
04 and 22 Arrivals November 2011
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Saffron Walden Community Noise Monitoring
04 and 22 Arrivals December 2011
04 and 22 Arrivals January 2012
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