College of Sciences staff by location (campus)

Dr Mathew Legg staff profile picture

Contact details +6492136849

Dr Mathew Legg BSc, MSc, PGDipSci, PhD

Senior Lecturer

Doctoral Supervisor
Engineering Group

Mathew's research relates to development of acoustics/ultrasonics tools and techniques. Prior to his current position at Massey, he was a postdoctoral research fellow at the University of Auckland where he worked on MBIE projects relating to the development of acoustics/ultrasonics instruments and techniques for measuring pasture biomass and the structural properties of trees. Before this he was a research fellow at Brunel Innovation Centre in Cambridge, UK where he performed research on the use of ultrasonic guided waves for nondestructive testing on several European Union projects. His PhD work related to the 3D acoustic imaging using microphone arrays (acoustic cameras).

New Zealand MBIE and European Union Projects worked on as Postdoc:

  • "Precision Acoustic Sensors for Pastoral and Arable Farming" (Oct 2015 – Sep. 2018), University of Auckland. Ministry of Business, Innovation and Employment (MBIE) project. Development of a smart ultrasonic sensor to measure pasture dry matter or crop growth.
  • "Acoustic Non-destructive Evaluation of Wood Properties in Standing Trees and Felled Stems" (May 2014 – Apr. 2016), University of Auckland. Subcontracted to UniServices by SCION from Ministry of Business, Innovation and Employment (MBIE). Developed novel acoustic/ultrasonic tools for measuring the internal stiffness of trees. Part of the Growing Confidence in Forestry Future project (http://gcff.nz/)
  • "CleanShip – Prevention and Detection of Fouling on Ship Hulls" (2013–2014) Brunel University. Collaborative European Union 7th Framework Program project. Development of a guided wave ultrasonic antifouling system for ships.(http://cleanship-project.eu/)
  • "Chaplin: High Power Transmission Line Cable Inspection" (2013–2014) Brunel University. Collaborative European Union 7th Framework Program project. Development of ultrasound guided wave inspection system hardware and signal processing software for defect detection on high voltage power lines. (http://www.chaplin-project.eu/1.html)
  • Safewire: Long Range Ultrasonic Inspection of Aircraft Wiring (2013–2014) Brunel University. Collaborative European Union 7th Framework Program project. Development of ultrasonic guided wave system for detection of defects in the insulation of aircraft wires. (http://safewire.eu)

PhD Research:

  • "Microphone Phased Array 3D Beamforming and Deconvolution" (2008-2012) University of Auckland. Supervisor: Prof. Stuart Bradley. Research related to development of image sharpening (deconvolution) of 3D acoustic maps generated using microphone arrays (acoustic cameras), beamforming algorithms, and computer vision techniques.

MSc Research:

  • "Multi-frequency Clutter-rejection Algorithms for Acoustic Radars" (2006-2007) University of Auckland. Supervisor: Prof. Stuart Bradley. Acoustic radar development for measuring wind profiles and rain drop size distribution.

Mathew's research relates to development of acoustics/ultrasonics tools and techniques. Prior to his current position at Massey, he was a postdoctoral research fellow at the University of Auckland where he worked on MBIE projects relating to the development of acoustics/ultrasonics instruments and techniques for measuring pasture biomass and the structural properties of trees. Before this he was a research fellow at Brunel Innovation Centre in Cambridge, UK where he performed research on the use of ultrasonic guided waves for nondestructive testing on several European Union projects. His PhD work related to the 3D acoustic imaging using microphone arrays (acoustic cameras).

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Professional

Contact details

  • Ph: +64 (0)9 2136849
    Location: AV2.2, Albany Villiage
    Campus: Auckland

Qualifications

  • Bachelor of Science - University of Auckland (2003)
  • Master of Science with First Class Honours - University of Auckland (2007)
  • Postgraduate Diploma in Science - University of Auckland (2004)
  • Doctor of Philosophy - University of Auckland (2012)

Research Expertise

Research Interests

Researcher has been in the areas of acoustic/ultrasonic imaging, Non-Destructive Testing (NDT) using ultrasonic bulk and guidedwaves, remote sensing, sensor development, signal processing, and 3D computer vision. This includes the use and development of:

  • Acoustic cameras/microphone arrays for imaging noise sources. (Commonly used in noise reduction studies for the aerospace and automotive industries.)
  • Ultrasonic guidedwave non-destructive testing tools. (Commonly used for identifying defects in pipelines for the oil and gas industry.)
  • Ultrasonic devices for measuring pasture properties for the agricultural industry.
  • Acoustic/ultrasonic tools for non-destructive testing of trees. (Commonly used for measuring stiffness of tree stems.)
  • Ultrasonic antifouling system for ships.

Area of Expertise

Field of research codes
Acoustics and Noise Control (excl. Architectural Acoustics) (091301): Agricultural Engineering (099901): Electrical and Electronic Engineering (090600): Engineering (090000): Materials Engineering (091200): Mechanical Engineering (091300): Other Engineering (099900): Signal Processing (090609)

Keywords

Acoustics, acoustic imaging, nondestructive testing, NDT, ultrasonic, ultrasound, microphone array, beamforming, ultrasonic guided waves, computer vision.

Research Projects

Summary of Research Projects

Position Current Completed
Project Leader 0 5

Research Outputs

Journal

Chew, MT., Alam, F., Noble, FK., Legg, M., & Gupta, GS. (2024). Visible Light Positioning-Based Robot Localization and Navigation. Electronics (Switzerland). 13(2)
[Journal article]Authored by: Legg, M., Sen Gupta, G.
Parr, B., Legg, M., & Alam, F. (2023). Grape yield estimation with a smartphone's colour and depth cameras using machine learning and computer vision techniques. Computers and Electronics in Agriculture. 213
[Journal article]Authored by: Legg, M.
Bakar, AHA., Legg, M., Konings, D., & Alam, F. (2023). The effects of dispersion on time-of-flight acoustic velocity measurements in a wooden rod. Ultrasonics. 129
[Journal article]Authored by: Legg, M.
Bakar, AHA., Legg, M., Konings, D., & Alam, F. (2023). Estimation of the Rod Velocity in Wood using Multi-frequency Guided Wave Measurements. Applied Acoustics. 202
[Journal article]Authored by: Legg, M.
Parr, B., Legg, M., & Alam, F. (2022). Analysis of Depth Cameras for Proximal Sensing of Grapes. Sensors. 22(11)
[Journal article]Authored by: Legg, M.
Faulkner, N., Konings, D., Alam, F., Legg, M., & Demidenko, S. (2022). Machine Learning Techniques for Device-Free Localization Using Low-Resolution Thermopiles. IEEE Internet of Things Journal. 9(19), 18681-18694
[Journal article]Authored by: Legg, M.
Bakar, AHA., Legg, M., Konings, D., & Alam, F. (2022). Ultrasonic guided wave measurement in a wooden rod using shear transducer arrays. Ultrasonics. 119
[Journal article]Authored by: Legg, M.
Faulkner, N., Alam, F., Legg, M., & Demidenko, S. (2021). Device-Free Localization Using Privacy-Preserving Infrared Signatures Acquired From Thermopiles and Machine Learning. IEEE Access. 9, 81786-81797
[Journal article]Authored by: Legg, M.
Chew, MT., Alam, F., Legg, M., & Gupta, GS. (2021). Accurate ultrasound indoor localization using spring‐relaxation technique. Electronics (Switzerland). 10(11)
[Journal article]Authored by: Legg, M., Sen Gupta, G.
Glass, T., Alam, F., Legg, M., & Noble, F. (2021). Autonomous fingerprinting and large experimental data set for visible light positioning. Sensors. 21(9)
[Journal article]Authored by: Legg, M.
Parr, B., Legg, M., Bradley, S., & Alam, F. (2021). Occluded grape cluster detection and vine canopy visualisation using an ultrasonic phased array. Sensors. 21(6), 1-20
[Journal article]Authored by: Legg, M.
Legg, M., & Bradley, S. (2020). Ultrasonic arrays for remote sensing of pasture biomass. Remote Sensing. 12(1)
[Journal article]Authored by: Legg, M.
Faulkner, N., Parr, B., Alam, F., Legg, M., & Demidenko, S. (2020). Caploc: Capacitive sensing floor for device-free localization and fall detection. IEEE Access. 8, 187353-187364
[Journal article]Authored by: Legg, M.
Bakar, AHA., Glass, T., Tee, HY., Alam, F., & Legg, M. (2021). Accurate Visible Light Positioning Using Multiple-Photodiode Receiver and Machine Learning. IEEE Transactions on Instrumentation and Measurement. 70
[Journal article]Authored by: Legg, M.
Faulkner, N., Alam, F., Legg, M., & Demidenko, S. (2020). Watchers on the Wall: Passive Visible Light-Based Positioning and Tracking with Embedded Light-Sensors on the Wall. IEEE Transactions on Instrumentation and Measurement. 69(5), 2522-2532
[Journal article]Authored by: Legg, M.
Legg, M., & Bradley, S. (2019). Ultrasonic proximal sensing of pasture biomass. Remote Sensing. 11(20)
[Journal article]Authored by: Legg, M.
Alam, F., Faulkner, N., Legg, M., & Demidenko, S. (2019). Indoor Visible Light Positioning Using Spring-Relaxation Technique in Real-World Setting. IEEE Access. 7, 91347-91359
[Journal article]Authored by: Legg, M.
Yucel, MK., Legg, M., Vassilios, K., & Gan, T. (2017). An ultrasonic guided wave approach for the inspection of overhead transmission line cables. Applied Acoustics. 122, 23-34 Retrieved from http://www.sciencedirect.com/science/article/pii/S0003682X17301317
[Journal article]Authored by: Legg, M.
Habibi, H., Gan, TH., textbfLegg, M., de Carellan, IG., Kappatos, V., Tzitzilonis, V., . . . Selcuk, C. (2016). Acoustic antifouling study with application for ship hulls. International Journal of Engineering Technologies and Management Research. 3, 14-30
[Journal article]Authored by: Legg, M.
Legg, M., & Bradley, S. (2016). Measurement of stiffness of standing trees and felled logs using acoustics: A review. Journal of the Acoustical Society of America. 139(2), 588-604
[Journal article]Authored by: Legg, M.
Legg, M., Yücel, MK., Kappatos, V., Selcuk, C., & Gan, TH. (2015). Increased range of ultrasonic guided wave testing of overhead transmission line cables using dispersion compensation. Ultrasonics. 62, 35-45
[Journal article]Authored by: Legg, M.
Legg, M., Yücel, MK., Garcia De Carellan, I., Kappatos, V., Selcuk, C., & Gan, TH. (2015). Acoustic methods for biofouling control: A review. Ocean Engineering. 103, 237-247
[Journal article]Authored by: Legg, M.
Legg, M., & Bradley, S. (2014). Automatic 3D scanning surface generation for microphone array acoustic imaging. Applied Acoustics. 76, 230-237
[Journal article]Authored by: Legg, M.
Legg, M., & Bradley, S. (2013). A combined microphone and camera calibration technique with application to acoustic imaging. IEEE Transactions on Image Processing. 22(10), 4028-4039
[Journal article]Authored by: Legg, M.
Yücel, MK., Fateri, S., Legg, M., Wilkinson, A., Kappatos, V., Selcuk, C., . . . Gan, TH. (2016). Coded Waveform Excitation for High-Resolution Ultrasonic Guided Wave Response. IEEE Transactions on Industrial Informatics. 12(1), 257-266
[Journal article]Authored by: Legg, M.

Book

Scott, J., Legg, M., & Konings, D. (2022). Lightboard streaming technology for teaching and learning: Responding to student wellbeing and enhancing online learning. In Academic Voices: A Conversation on New Approaches to Teaching and Learning in the post-COVID World. (pp. 29 - 41).
[Chapter]Authored by: Legg, M., Scott, J.

Thesis

Legg, M. (2012). Microphone phased array 3D beamforming and deconvolution. (Doctoral Thesis, University of Auckland) Legg, M. (2012). Microphone phased array 3D beamforming and deconvolution. (Doctoral Thesis)
[Doctoral Thesis]Authored by: Legg, M.
Legg, M. (2007). Multi-frequency clutter-rejection algorithms for acoustic radars. (Master's Thesis)
[Masters Thesis]Authored by: Legg, M.

Conference

Legg, M.(2022, July). Ultrasonic sensing of pasture biomass. .
[Conference]Authored by: Legg, M.
Konings, D., & Legg, M. (2021). Delivering an Effective Balance of Soft and Technical Skills within Project-Based Engineering Courses. IEEE Xplore. : 2020 IEEE International Conference on Teaching, Assessment, and Learning for Engineering (TALE)
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Parr, B., Konings, D., Legg, M., & Alam, F. (2020). Early Warning System with Real Time Tilt Monitoring. 2019 29th International Telecommunication Networks and Applications Conference (ITNAC).
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Parr, B., Legg, M., & Cox, S. (2020). Development of a Hand-held 3D Scanning Acoustic Camera. 2020 IEEE Sensors Applications Symposium, SAS 2020 - Proceedings.
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Hasan, A., Glass, T., Alam, F., & Legg, M. (2020). Fingerprint-Based Visible Light Positioning using Multiple Photodiode Receiver. 2020 IEEE Sensors Applications Symposium, SAS 2020 - Proceedings.
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Faulkner, N., Parr, B., Alam, F., Legg, M., & Demidenko, S. (2020). Device Free Localization with Capacitive Sensing Floor. 2020 IEEE Sensors Applications Symposium, SAS 2020 - Proceedings.
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Parr, B., Legg, M., Alam, F., & Bradley, S. (2020). Acoustic Identification of Grape Clusters Occluded by Foliage. 2020 IEEE Sensors Applications Symposium, SAS 2020 - Proceedings.
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Beckley, A., Parr, B., Mathrani, S., Legg, M., & Drain, A. (2020). Mechanical Requirements for a Smart Inhaler Product. 2020 IEEE Sensors Applications Symposium, SAS 2020 - Proceedings.
[Conference Paper in Published Proceedings]Authored by: Legg, M., Mathrani, S.
Bradley, S., & Legg, M.Precision ultrasonic sonar for pasture biomass. . Montpellier, France
[Conference Paper]Authored by: Legg, M.
Bradley, S., & Legg, M. (2019). Ultrasonic remote sensing for precision agriculture. Proceedings of the International Congress on Acoustics. Vol. 2019-September (pp. 4977 - 4982).
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Parr, B., Konings, D., Legg, M., & Alam, F. (2019). Early Warning System with Real Time Tilt Monitoring. 2019 29th International Telecommunication Networks and Applications Conference, ITNAC 2019.
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Bradley, S., & Legg, M. (2019). Adaptable beam-width ultrasound array for remotely sensing vegetation properties. INTER-NOISE 2019 MADRID - 48th International Congress and Exhibition on Noise Control Engineering.
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Bradley, S., & Legg, M. (2019). Adaptable beam-width ultrasound array for remotely sensing vegetation properties. INTER-NOISE 2019 MADRID - 48th International Congress and Exhibition on Noise Control Engineering.
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Faulkner, N., Alam, F., Legg, M., & Demidenko, S. (2019). Smart wall: Passive visible light positioning with ambient light only. I2MTC 2019 - 2019 IEEE International Instrumentation and Measurement Technology Conference, Proceedings. Vol. 2019-May
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Legg, M., & Bradley, S. (2017). Low frequency highly directional air coupled ultrasound sensor. 24th International Congress on Sound and Vibration, ICSV 2017.
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Legg, M., & Bradley, S. (2016). Anisotropic stiffness tensor measurement for standing trees using acoustics. American Society of Nondestructive Testing (ASNT) Annual Conference. (pp. 1 - 9). : ASNT Annual Conference
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Bradley, S., Mikkelsen, T., von Hünerbein, S., & Legg, M. (2016). Wind turbine noise source characteristics measured with a large microphone array. Proceedings of the 22nd International Congress on Acoustics. (pp. 1 - 1). : 22nd International Congress on Acoustics
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Yücel, MK., Fateri, S., Legg, M., Wilkinson, A., Kappatos, V., Selcuk, C., . . . Gan, TH. (2015). Pulse-compression based iterative time-of-flight extraction of dispersed Ultrasonic Guided Waves. Proceeding - 2015 IEEE International Conference on Industrial Informatics, INDIN 2015. (pp. 809 - 815).
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Parthipan, T., Jackson, P., Chong, A., Legg, M., Mohimi, A., Kappatos, V., . . . Hrissagis, K. (2014). Long Range Ultrasonic inspection of aircraft wiring. IEEE International Symposium on Industrial Electronics. (pp. 1289 - 1294).
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Bradley, S., Mikkelsen, T., von Hünerbein, S., & Legg, M. (2016). Precision measurements of wind turbine noise using a large aperture microphone array. 6th Berlin Beamforming Conference, Berlin. 29 Feb. – 1 Mar..
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Parthipan, T., Jackson, P., Chong, A., Legg, M., Mohimi, A., Kappatos, V., . . . Hrissagis, K. (2014). Long range ultrasonic inspection of aircraft wiring. Industrial Electronics (ISIE), 2014 IEEE 23rd International Symposium on. (pp. 1289 - 1294). : a
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Legg, M., & Bradley, S. (2012). Comparison of CLEAN-SC for 2D and 3D scanning surfaces. (pp. 1 - 11). : 4th Berlin Beamforming Conference
[Conference Paper in Published Proceedings]Authored by: Legg, M.
Yücel, MK., Fateri, S., Legg, M., Wilkinson, A., Kappatos, V., Selcuk, C., . . . Gan, TH. (2015). Pulse-compression based iterative time-of-flight extraction of dispersed ultrasonic guided waves. 2015 IEEE 13th International Conference on Industrial Informatics (INDIN). (pp. 809 - 815). : Industrial Informatics (INDIN), 2015 IEEE 13th International Conference on
[Conference Paper in Published Proceedings]Authored by: Legg, M.

Other

Yücel, MK., Legg, M., Kappatos, V., & Gan, TH. (2017). An ultrasonic guided wave approach for the inspection of overhead transmission line cables. (pp. 23 - 34).
[Other]Authored by: Legg, M.
Legg, M., Carellan, IG., Kappatos, V., Selcuk, C., Gan, T-H., Moustakidis, S., . . . Karayannis, T. (2014). CleanShip: A recent project for prevention and detection of fouling on ships.
[Other]Authored by: Legg, M.

IP

Legg, M., & Bradley, S.(2019). . 2019201425: Australia: Vegetation measurement apparatus, systems, and methods
[Patent]Authored by: Legg, M.
Legg, M., & Bradley, S.(2019). . .753949: New Zealand: Systems, apparatus and methods for vegetation measurement
[Patent]Authored by: Legg, M.

Teaching and Supervision

Teaching Statement

Summary of Doctoral Supervision

Position Current Completed
Main Supervisor 4 2
Co-supervisor 2 2

Current Doctoral Supervision

Main Supervisor of:

  • Eric Ma - Doctor of Philosophy
    Privacy-Preserving HAR Using Infrared Signatures Acquired from Thermopile
  • Naina Naina - Doctor of Philosophy
    Novel circuit design for CMOS Analog Beamformer chip
  • Shakil Ahmed - Doctor of Philosophy
    D2D COMMUNICATION BASED DISASTER RESPONSE SYSTEM UNDER 5G NETWORKS
  • Moi Tin Chew - Doctor of Philosophy
    Novel Visible Light Positioning Techniques

Co-supervisor of:

  • Weijian Zhu - Doctor of Philosophy
    Analog CMOS Design of Deep Machine Learning
  • Jason Collingwood - Doctor of Philosophy
    Continuous High-Speed Resin 3D Printing for Microfluidics

Completed Doctoral Supervision

Main Supervisor of:

  • 2024 - Baden Parr - Doctor of Philosophy
    Grape yield analysis with 3D cameras and ultrasonic phased arrays
  • 2023 - Adli Abu Bakar - Doctor of Philosophy
    Acoustic Non-Destructive Testing for Wood

Co-supervisor of:

  • 2022 - Nathaniel Faulkner - Doctor of Philosophy
    Device-Free Indoor Localisation with Non-Wireless Sensing Techniques
  • 2022 - Tanisha Pereira - Doctor of Philosophy
    An investigation into non-destructive testing strategies and in-situ surface finish improvement for direct metal printing with SS 17-4PH

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