Flyover moving source beamforming

This PULSE software locates noise sources on low-flying aircraft in one measurement, as the aircraft flies over a large array of microphones laid out on the ground. The resulting noise maps can be overlaid on images of the aircraft, for easy relation of sound to its sources. The maps show sound in high resolution as colours emanating from the aircraft’s components such as the engines or landing gear. The sound’s strength and directivity are clearly represented by differently coloured contour rings, allowing viewers to clearly understand them.

USE SCENARIOS

• Research and development flyover tests
• Pre-aircraft noise certification analysis of contributions to effective perceived noise level (EPNL) at flight certification measurement points
• Identifying aeroacoustic noise contributions from high lift devices such as slats and flaps 
• Ranking noise source contributions such as fan noise and jet noise 

The flyover moving source beamforming system records acoustic time data and embeds a GPS time stamp into it. The system can then incorporate external information such as weather data and aircraft data, using identical timestamps to synchronize the datasets.

CAPABILITIES 

• Flyover tests at altitudes between 30 metres and 300 metres
• Usable frequency range of 600 Hz to 6 kHz, extendable down to 300Hz with a larger microphone array
• GPS timestamps data for correlation to flight track and aircraft parameters such as engine speed, position, speed, roll, yaw and pitch
• Incorporates environmental data such as temperature, relative humidity, barometric pressure, wind speed, direction, and precipitation
• Photographic validation of position of aircraft for on-the-spot synchronization with acoustical data
• Fast validation onsite

Quick deployment is important when making measurements on busy runways, and during flight test programmes where acoustics is not the primary purpose. The system works with a horizontal wheel array that is designed for quick, precise set-up.

Flyover Moving Source Beamforming Type BZ-5940 is an optional addition to PULSE Array Acoustics Beamforming Type 8608.