Noise Contour Map, Measurement, Survey, WECPNL, LDEN
Recently, complaints about noise caused by transportation means such as road traffic, railroad, and aircraft are increasing, and the aviation noise has very high level and its propagated area is wide. Due to the nature of the aircraft noise source, it is not easy to establish the countermeasures & noise reduction against sound source, propagation path. And, it should be noted that the characteristics about difference is very severe depending on the type of engine, flight alitude, and flight type. This is due to the noise level felt by residents according to the flight schedule is more serious. INERTANCE Inc. evaluates the status of aviation noise in adjacent residential areas, including measurement, analysis with noise contour map preparation against aircraft sound. The scope of the aviation noise evaluation is as follows;
- Aircraft sound Measurement
- Aviation Noise Estimation
- Noise Contour Map
- INM (Integrated Noise Model)
- AEDT (Aviation Environmental Design Tool)
- WECPNL (Weighted Equivalent Continuous Perceived Noise Level)
- LDEN (Day Evening Night Noise Level)
- Environmental Noise Assessment
- Aircraft Noise Propatation Path
- Background Noise
- Survey for Flight Path
Aircraft Noise Measurement
Aircraft noise measurement is performed in accordance with Local standard method regarding noise vibration process test in South Korea, and the accuracy and uniformity of the measurement to be maintained.
- Sound Level Meter with higher grade than Class 2 of KS C IEC 61672-1
- A-Weight, Slow response
- Location that can represent aviation noise
- Location with no abstacles around measurement point
- Windscreen in case of wind velocity above 2m/s
- Actual count of flight path & pass
- Continuous measurement for Seven (7) days
WECPNL, LDEN (Noise Level Unit)
Aviation noise is evaluated according to WECPNL and LDEN units. Daily evaluation of WECPNL unit can be done as follows;
- N: Daily count for aviation noise measurement
- N1: 00:00~06:59, Count for Night-time
- N2: 07:00~18:59, Count for Day-time
- N3: 19:00~21:59, Count for Evening-time
- N4: 22:00~23:59, Count for Night-time
The noise level as LDEN unit was proposed by US Environmental Protection Agency (EPC), and the related weight factor of time schedule are applied with consideration that noise are felt louder in the evening and at night than daytime.
- T: Noise Measurement Time
- T0: Time Reference
- LAE,di: Noise Exposure Level, Day-time
- LAE,ej: Noise Exposure Level, Evening-time
- LAE,nk: Noise Exposure Level, Night-time
Aviation Noise Contour Map
See below the general procedure to assess the contour map of aircraft noise.
INM (Integrated Noise Model) is a commercial aircraft noise prediction program announced by the Federal Aviation Administration (FAA) in 1978, and is recognized as a standard tool for the FAA’s aircraft noise prediction and assesses the impact of aircraft sound due to the construction and expansion of airport runways. It has been used to evaluate changes in routes, flight routes, and operational procedures. Meanwhile, in 2015, the U.S. Federal Aviation Administration developed AEDT (Aviation Environmental Design Tool), an integrated environmental management software related to aircraft operation, and the existing program INM) was integrated into AEDT. INERTANCE Inc. understands the latest prediction techniques through comparison of INM and AEDT analysis techniques and creates aircraft noise contours by reflecting practical technical details on differences.
Below figures show the comparative analysis of INM and AEDT for the same aircraft operating conditions.
Related Engineering Services
INERTANCE has a capability regarding noise and vibration engineering, and our experts are familiar with assessment of environmental noise.
For further information, contact us at (firstname.lastname@example.org).INERTANCE Inc.