Browsing by Author "Lie-Svendsen, Øystein"

Now showing items 1-11 of 11

    • Analysis of detection performance of incoherent range walk compensation for passive radar 

      Finden, Erlend; Christiansen, Jonas Myhre; Lie-Svendsen, Øystein; Olsen, Karl Erik (2015)
      This paper analyzes the performance of an incoherent range walk compensation method for passive radar systems. The method utilizes the velocity information in the range-Doppler map, and no detection before compensation ...

    • Beamforming of synthetic target signal acquired by the Atlantis PCL system 

      Strøm, Kyrre; Finden, Erlend; Schell, Jochen; Norheim-Næss, Idar; Lie-Svendsen, Øystein (2016-09-20)
      The passive coherent location system, Atlantis, is a test bed for digital beamforming at the Norwegian Defence Research Establishment (FFI). The system has functionality for real time direction of arrival (DoA) estimation. ...

    • Detection performance for Incoherent Range Walk Compensation 

      Finden, Erlend; Christiansen, Jonas Myhre; Lie-Svendsen, Øystein; Olsen, Karl Erik (2014-11-24)
      FFI supports the Royal Norwegian Air Force in their acquisition of new air surveillance sensors. Improved detection performance on low observable targets may be obtained by increasing the radar dwell time on target. For ...

    • DSI Suppression with Adaptive Beamforming in DVB-T Passive Radar Measurements 

      Strøm, Kyrre; Lie-Svendsen, Øystein; Norheim-Næss, Idar; Johnsen, Terje; Finden, Erlend; Olsen, Karl Erik (2018)
      Adaptive beamforming (ABF) for maximizing the signal to interference plus noise ratio (SINR) is applied to acquisitions made by a passive bistatic radar (PBR) exposed to strong direct signal interference (DSI). The DVB-T ...

    • DVB-T Passive Radar Dual Polarization Measurements in the Presence of Strong Direct Signal Interference 

      Strøm, Kyrre; Lie-Svendsen, Øystein; Finden, Erlend; Norheim-Næss, Idar; Johnsen, Terje; Baruzzi, Aurora (2017)
      A dual-polarization passive bistatic radar is used to evaluate the potential benefit of cross-polarized measurements for the suppression of strong direct signal interference in the DVB-T band. The linear array antenna ...

    • EFFECT OF COULOMB COLLISIONS ON THE GRAVITATIONAL SETTLING OF LOW AND HIGH FIRST IONIZATION POTENTIAL ELEMENTS 

      Bø, Iselin M Thomassen; Esser, Ruth; Lie-Svendsen, Øystein (2013)
      We model the effect of gravitational settling in the upper chromosphere on O, Fe, Si, and Ne, studying whether Coulomb collisions between ionized low First Ionization Potential (FIP) elements and protons is sufficient to ...

    • ELEMENTAL ABUNDANCES IN THE FAST SOLAR WIND EMANATING FROM CHROMOSPHERIC FUNNELS 

      Pucci, Stefano; Lie-Svendsen, Øystein; Esser, Ruth (2010)
      We carry out a model study to determine whether a funnel-type flow geometry in the solar wind source region leads to sufficiently fast hydrogen flow to offset heavy element gravitational settling and can thus explain why ...

    • MODELING IRON ABUNDANCE ENHANCEMENTS IN THE SLOW SOLAR WIND 

      Byhring, Hanne Sigrun; Cranmer, S.R.; Lie-Svendsen, Øystein; Habbal, S. Rifai; Esser, Ruth (2011)
      We have studied the behavior of Fe ions in the slow solar wind, using a fluid model extending from the chromosphere to 1 AU. Emphasis is on elemental "pileup" in the corona, i.e., a region where the Fe density increases ...

    • O and Ne in an H-He Fast Solar Wind 

      Byhring, Hanne Sigrun; Esser, Ruth; Lie-Svendsen, Øystein (2011)
      We have studied the abundances and ion fractions of O and Ne in an H-He fast solar wind with emphasis on gravitational settling in the chromosphere and corona. We use a time-dependent numerical model that spans the mid- ...

    • Solar Wind from Coronal Funnels and Transition Region Lyalpha 

      Esser, Ruth; Lie-Svendsen, Øystein; Janse, Åse Marit; Killie, Mari Anne (2005)
      Using a newly developed gyrotropic solar wind model that extends continuously from the mid-chromosphere to 1 AU and that accounts for radiative losses in the transition region, we have studied the difference between the ...

    • The ECOMA 2007 campaign: rocket observations and numerical modelling of aerosol particle charging and plasma depletion in a PMSE/NLC layer 

      Brattli, Alvin Andreas; Lie-Svendsen, Øystein; Svenes, Knut Ragnar; Hoppe, Ulf-Peter; Strelnikova, I.; Rapp, M.; Latteck, R.; Friedrich, M. (2009)
      The ECOMA series of rocket payloads use a set of aerosol particle, plasma, and optical instruments to study the properties of aerosol particles and their interaction with the ambient plasma environment in the polar mesopause ...