Apart from its fast and intuitive user interface the biggest strength of gfai tech’s powerful software suite NoiseImage is its completely modular structure and easy scalability. Not only standard acoustic imaging scenarios like two-dimensional acoustic pictures are supported but also more specialized analysis workflows like acoustic nearfield and holography, pass-by measurements of vehicles, acoustic imaging of vehicles in the wind tunnel, order analysis and psychoacoustics. NoiseImage can be expanded with any combination of these specialized modules allowing you to individually put together your own solution for acoustic imaging according to your needs.

Near Field

This module is required for the usage of the intensity or holography methods (HELS and SONAH). It creates images of sound intensity, sound pressure or particle velocity. The Near Field module closes the gap to mapping of low frequencies without applying big microphone arrays.

  • HELS and SONAH
  • Holography – mapping of sound intensity, sound pressure and particle velocity
  • Intensity – acoustic mapping of sound intensity
  • Phase representation of complex values

PassBy

The PassBy module optimizes any pass-by measurement and is especially designed for long vehicles like trucks or trains. With a simple one-shot measurement the acoustic and optical data is captured. The pass-by algorithms generate a panoramic image of the complete object (trains of several hundred meters) and the acoustic data is mapped on the full vehicle for instant analysis of the complete object. Besides the panoramic image the vehicle speed is calculated and the acoustic data is cleaned of the doppler effect to eliminate frequency shifts. It is a robust algorithm designed for measurements on the field hence it compensates any array rotation.

  • Acoustic map in 2D of the whole vehicle (optimized for fast pass-by of trains) 
  • Generation of a panoramic image based on the recorded video 
  • Automatic Doppler correction
  • Compensation of a possible array rotation
  • Calculation of the speed profile as well as the entry and exit times of the vehicle
  • Grayscale and edge detection photos
  • Beamforming in the frequency domain
  • Photo exports (e.g. .jpg, .png, ....)

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Acoustic Analysis of a Truck Passing by

Wind Tunnel

As the driver’s and passenger’s comfort even at high speeds play a crucial role in the automotive industry it becomes more important to acoustically optimize vehicles in regard of the noise induced by wind. 

Modern aero-acoustic wind tunnels allow for acoustic tests at high speeds and as highest quality and precision is demanded by the automotive companies gfai tech took a huge step in setting new standards for acoustic imaging in wind tunnels. More than 20 years of experience in the field and many successful cooperations with different car manufacturers lead to state of the art hard- and software. Customized array design, high channel counts and a number of optimized algorithms guarantee the best possible results for acoustic imaging in wind tunnels. Due to the adjustable hard ware our solution is not limited to the automotive area and the aerospace and transport industry is already successfully applying our systems.

The NoiseImage Wind Tunnel module holds all the wind tunnel specific algorithms as a basis for your analysis of data acquired in the wind tunnel.

  • Shear layer correction
  • Wind speed correction
  • Space and amplitude correction of sources inside the shear layer
  • Measurements of vehicles under different angles
  • Combination with all other NoiseImage features
  • Optimized 3D mapping in combination with the NoiseImage 3D module
  • Wind tunnel measurements for automotive, aerospace and other transport areas
  • Variant analyses in product development

Psychoacoustics / Sound Quality

Psychoacoustic parameters like loudness, sharpness, tonality or roughness are important quantifications to better describe sound in relation to the human perception.

So far those values have only been used for abstract analysis of signals. With the NoiseImage module Psychoacoustic you can combine that information with acoustic imaging and actually generate acoustic maps based on the most important quantities. This provides a powerful tool for enhancement of sound quality and efficient noise reduction especially in relation to the user perception.

  • Computation of loudness, sharpness, roughness and tonality
  • Mapping of loudness, sharpness, roughness
  • Optimization of psychoacoustic sound quality

Order Analysis

For working with rotating movement, Order Analysis allows the detection of angular velocities and therefore is an alternative to the classical beamforming transformation. The key advantage is that speed-dependent signal components retain their position in the order spectrum even if the rotational speed is changing. Order and frequency cursors and order filtering enable even further analyses of rotating equipment. The NoiseImage module Order Analysis allows you to combine your standard order analysis with instant acoustic mapping.

  • Order Spectrum
  • Ordergram
  • Changing of reference-values between orders / time / rpm
  • Order Photo 2D/3D: Acoustic Photos from Order Spectrum/ Ordergram
  • Order Movie: Acoustic Movies from Order Spectrum/ Ordergram
  • Order-line in spectrogram/ frequency-line in ordergram
  • Rotating ojects
  • Engine analysis