Blar i forfatter "Clahsen, Matthias"

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    • Four-dimensional mesospheric and lower thermospheric wind fields using Gaussian process regression on multistatic specular meteor radar observations 

      Volz, Ryan; Chau, Jorge L.; Erickson, Philip J.; Vierinen, Juha P.; Urco, J. Miguel; Clahsen, Matthias (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-17)
      Mesoscale dynamics in the mesosphere and lower thermosphere (MLT) region have been difficult to study from either ground- or satellite-based observations. For understanding of atmospheric coupling processes, important spatial scales at these altitudes range between tens and hundreds of kilometers in the horizontal plane. To date, this scale size is challenging observationally, so structures are ...

    • Frequency spectra of horizontal winds in the mesosphere and lower thermosphere region from multistatic specular meteor radar observations during the SIMONe 2018 campaign 

      Charuvil, Harikrishnan; Chau, Jorge L.; Marino, Raffaele; Vierinen, Juha; Vargas, Fabio; Urco, Juan M.; Clahsen, Matthias; Jacobi, Christoph (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-11)
      In recent years, multistatic specular meteor radars (SMRs) have been introduced to study the Mesosphere and Lower Thermosphere (MLT) dynamics with increasing spatial and temporal resolution. SMRs, compared to other groundbased observations, have the advantage of continuously measuring the region between 80 and 100 km independent of weather, season, or time of day. In this paper, frequency spectra ...

    • Investigating Spatial and Temporal Structuring of E-Region Coherent Scattering Regions Over Northern Norway 

      Huyghebaert, Devin Ray; Chau, Jorge L.; Spicher, Andres; Ivarsen, Magnus Fagernes; Clahsen, Matthias; Latteck, Ralph; Vierinen, Juha-Pekka (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-26)
      Recently, it has been shown that the Spread Spectrum Interferometric Multistatic meteor radar Observing Network radar system located in northern Norway is capable of measuring ionospheric E-region coherent scatter with spatial and temporal resolutions on the order of 1.5 km and 2 s, respectively. Four different events from June and July of 2022 are examined in the present study, where the coherent ...

    • Multiple E-Region Radar Propagation Modes Measured by the VHF SIMONe Norway System During Active Ionospheric Conditions 

      Huyghebaert, Devin Ray; Clahsen, Matthias; Chau, Jorge L.; Renkwitz, Toralf; Latteck, Ralph; Johnsen, Magnar Gullikstad; Vierinen, Juha (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-10)
      Multiple propagation modes between different bistatic radar links were measured during the operations of a very high frequency (VHF) 32.55 MHz radar system in northern Norway. The Spread Spectrum Interferometric Multistatic meteor radar Observing Network (SIMONe) Norway system detected meteor trails, direct transmitter to receiver signal propagation, over-the-horizon signal propagation from the ...

    • Multistatic Specular Meteor Radar Network in Peru: System Description and Initial Results 

      Chau, Jorge L.; Urco, Miguel; Vierinen, Juha; Harding, Brian; Clahsen, Matthias; Pfeffer, Nico; Kuyeng, Karim; Milla, Marco; Erickson, Philip J. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-10)
      The mesosphere and lower thermosphere (MLT) region is dominated globally by dynamics at various scales: planetary waves, tides, gravity waves, and stratified turbulence. The latter two can coexist and be significant at horizontal scales less than 500 km, scales that are difficult to measure. This study presents a recently deployed multistatic specular meteor radar system, SIMONe Peru, which can be ...

    • Novel specular meteor radar systems using coherent MIMO techniques to study the mesosphere and lower thermosphere 

      Chau, J. L.; Urco, Miguel; Vierinen, Juha; Volz, Ryan; Clahsen, Matthias; Pfeffer, Nico; Trautner, Jörg (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-05)
      Typical specular meteor radars (SMRs) use one transmitting antenna and at least a five-antenna interferometric configuration on reception to study the mesosphere and lower thermosphere (MLT) region. The interferometric configuration allows the measurement of the angle-of-arrival (AOA) of the detected meteor echoes, which in turn is needed to derive atmospheric parameters (e.g., mean winds, momentum ...

    • Observing Mesospheric Turbulence With Specular Meteor Radars: A Novel Method for Estimating Second-Order Statistics of Wind Velocity 

      Vierinen, Juha; Chau, Jorge L.; Charuvil, Harikrishnan; Urco, Miguel; Clahsen, Matthias; Avsarkisov, Victor; Marino, Raffaele; Volz, Ryan (Journal article; Peer reviewed, 2019-07)
      There are few observational techniques for measuring the distribution of kinetic energy within the mesosphere with a wide range of spatial and temporal scales. <br>This study describes a method for estimating the three‐dimensional mesospheric wind field correlation function from specular meteor trail echoes. Each radar echo provides a measurement of a one‐dimensional projection of the wind velocity ...