NA-37 For Environmental Measurement
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Environmental Sound Monitor (For Aircraft Noise Measurement)

Designed for Long-term Aircraft Noise Monitoring Application. Provides Functionality, Durability and Easy Maintenance Required for Automated System. Environmental Sound Monitor NA-37 The NA-37 is an automated aircraft noise monitoring system. The system has a feature for reliable identification of aircraft noise, while its compact dimensions make it suitable also for mobile use. Measurement is fully automatic, and continuous 365-day all-weather operation is supported. Configuration example of an aircraft noise measurement system Outdoor microphone MS-11 with windscreen Online communication...

NA-37 Related Products Sound Level Meter NA-83 The NA-83 conforms to the requirements of IEC 61672-1:2002 Class 1 (The conditions of the microphone attached the window screen and 30 m connected them with the specialized cable.) CE mark, EMC directive compliant (reduction of influence on an external electromagnetic noise) Outdoor Microphone System Outdoor Microphone MS-11 MS-11 has a built-in heater and a built-in sound source for automatic calibration, and is suitable for long-term outdoor use. WS-13 has bird spikes to keep birds away. Wind noise reduction effect of WS-13 120 C...

For Aircraft Noise Measurement Aircraft Noise Measurement under the flight course Aircraft Noise Processing Program NX-37B Aircraft Noise Data Processing Application Software AS-50PA1 Aircraft noise event detection method (single noise) Maximum noise level Threshold level Background noise level (BGN) Symbols (noise event evaluation result) being detected Other surface Noise level Event time Noise event period (Noise event detected) Evaluation result display (noise other than aircraft) Evaluation result display Monitoring system installed in the vicinity of an airport Aircraft Noise Data...

For Aircraft Noise and Ground Noise Measurement Measurement of aircraft and ground noise in the vicinity of airports Aircraft Noise Processing Program NX-37C Aircraft Noise Data Processing Application Software Ground noise event detection method (long term noise event) NX-37C Noise level (one second) (Engine testing) 10 dB (Optional setting) Time Background noise level Start Single noise period Long term noise period (more than 300 seconds) The fixed threshold background noise method and running statistics background noise method are used to detect the long term noise event period. The...

Description of ground noise Visualization of how ground noise is generated Airport terminal Use up to five window areas to distinguish aircraft noise and ground noise from other noise (noise to be excluded). Single noise event Landing noise This noise occurs from the time the aircraft starts to taxi out from the end of the runway to the time it reaches the middle of the runway and finally takes off. This noise occurs as the aircraft descends, touches down on the runway of the airport, and then reverses the thrust direction of the engines to reduce speed as it leaves the runway. Long term...

Application System Software Examples Engine testing This small engine (Auxiliary Power Unit) from the main aircraft source used to supply hydraulic pressure. This refers to increasing engine output and taking off from the ground after reducing speed on the runway take-off and landing training. This refers to when a helicopter lifts off and remains Public Real-Time Information System This system collects data from many NA-37 installed in the vicinity of the airport and displays quickly the noise condition in real time and stores data. The link between data monitoring points, servers, and...

Four Microphones Allow Measurement of Elevation Angle and Azimuth Angle Aircraft Noise Identification Unit AN-37 AN-37R (with radar receiver) Correlation method of 3-axis microphones using only sound signals enables the system to determine sound arrival direction. Mainly used as the identification system for aircraft noise monitoring in the vicinity of airports. Also suitable for determining the sound source type based on sound arrival direction. Typical sound source direction vector data obtained by Aircraft Noise Identification Unit Direction vector data of Aircraft noise Direction vector...

Identification of sky sound using correlation method Two microphones are arranged in a perpendicular position as shown in Figure 1, with the distance between the microphones expressed as . When the sound from an aircraft arrives with an elevation angle , the following equation applies, where is the time difference between the arrival time of the sound at the two microphones (M1, M2), and c is the acoustic speed in air. Based on the equation, the elevation angle can be determined. c When the sound arrival direction is sufficiently steep ( > 0), the elevation angle information can be used for...

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Specifications subject to change without notice. 3-20-41, Higashimotomachi, Kokubunji, Tokyo 185-8533, Japan Tel: +81-42-359-7888 Fax: +81-42-359-7442 This leaflet is printed with environmentally friendly soy ink on recycled paper. 1006-1