Browsing NTNU Open by Author "Näsholm, Sven Peter"

Now showing items 1-7 of 7

    • Benchmarking microbarom radiation and propagation model against infrasound recordings: a vespagram-based approach 

      Vorobeva, Ekaterina; De Carlo, Marine; Le Pichon, Alexis; Espy, Patrick Joseph; Näsholm, Sven Peter (Journal article; Peer reviewed, 2021)
      This study investigates the use of a vespagram-based approach as a tool for multi-directional comparison between simulated microbarom soundscapes and infrasound data recorded at ground-based array stations. Data recorded ...

    • Exploiting infrasound to probe the dynamics of the middle atmosphere 

      Vorobeva, Ekaterina (Doctoral theses at NTNU;2023:214, Doctoral thesis, 2023)
      This doctoral thesis examines the middle atmosphere (30 - 80 km altitude) using ground-based observations of low-frequency sound waves (infrasound). By exploiting infrasound waves, the thesis aims to increase observations ...

    • High-speed Echoes in the Polar Winter Mesosphere: Infrasound as a Probable Cause 

      Belova, Evgenia; Barabash, Victoria; Godin, Oleg A.; Kero, Johan; Näsholm, Sven Peter; Vorobeva, Ekaterina; Pichon, Alexis Le (Peer reviewed; Journal article, 2023)
      We considered three events on 4 November 2015, 22 December 2016, and 12 November 2018, when the signals travelling in the polar winter mesosphere with high horizontal velocities above 300 m/s were measured by the atmospheric ...

    • Probing Gravity Waves in the Middle Atmosphere Using Infrasound From Explosions 

      Vorobeva, Ekaterina; Assink, Jelle; Espy, Patrick Joseph; Renkwitz, Toralf; Chunchuzov, Igor; Näsholm, Sven Peter (Peer reviewed; Journal article, 2023)
      This study uses low-frequency, inaudible acoustic waves (infrasound) to probe wind and temperature fluctuations associated with breaking gravity waves (GWs) in the middle atmosphere. Building on an approach introduced by ...

    • SURF Imaging Beams in an Aberrative Medium: Generation and Postprocessing Enhancement 

      Näsholm, Sven Peter; Angelsen, Bjørn Atle J. (Peer reviewed; Journal article, 2012)
      This paper presents numerical simulations of dual-frequency second-order ultrasound field (SURF) reverberation suppression transmit-pulse complexes. Such propagation was previously studied in a homogeneous medium. In this ...

    • Transmit Beams Adapted to Reverberation Noise Suppression Using Dual-Frequency SURF Imaging 

      Näsholm, Sven Peter; Hansen, Rune; Måsøy, Svein-Erik; Johansen, Tonni Franke; Angelsen, Bjørn Atle J. (Peer reviewed; Journal article, 2009)
      A method that uses dual-frequency pulse complexes of widely separated frequency bands to suppress noise caused by multiple scattering or multiple reflections in medical ultrasound imaging is presented. The excitation pulse ...

    • Ultrasound beams for enhanced image quality 

      Näsholm, Sven Peter (Dissertations at the Faculty of Medicine, 0805-7680; 2008-152, Doctoral thesis, 2008)
      The contents of this thesis consider new methods for generating ultrasound beams for enhanced image quality in medical imaging. The results presented are produced through computer simulations. The thesis consists of an ...