Blar i forfatter "Quigley, Cornelius Patrick"

Viser treff 1-6 av 6

    • An alternative approach for calculating the SAR damping ratio of verified oil slicks 

      Quigley, Cornelius Patrick; Johansson, Malin; Jones, Cathleen Elaine (Journal article; Tidsskriftartikkel; Peer reviewed, 2022)
      The damping ratio is a calculated feature that measures the contrast between oil-slicked water and the open ocean in SAR data. To implement the damping ratio, the current literature suggests estimating the open water backscatter by taking strips of undefined width across the range direction, obtaining the damping ratio as a function of incidence angle. We show in this paper that the method proposed ...

    • A Comparison Between Oil-to-Water Volumetric Fractions Derived from L-Band Synthetic Aperture Radar Imagery and in Situ Samples 

      Quigley, Cornelius Patrick; Johansson, Malin; Jones, Cathleen Elaine; Garcia, Óscar; Monaldo, Frank (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-20)
      We compare in-situ water volume measurements of mineral oil emulsion sampled from an oil slick in Santa Barbara, California, to acquisitions of airborne UAVSAR data acquired in June 2022. Estimating the water-to-oil fraction using the UAVSAR imagery, we find that low SNR in the co- and cross-polarimetric channels limits this capability above a certain oil-to-water volumetric threshold. Higher SNR ...

    • A dataset of direct observations of sea ice drift and waves in ice 

      Rabault, Jean; Müller, Malte; Voermans, Joey; Brazhnikov, Dmitry; Turnbull, Ian; Marchenko, Aleksey; Biuw, Martin; Nose, Takehiko; Waseda, Takuji; Johansson, Malin; Breivik, Øyvind; Sutherland, Graig; Hole, Lars Robert; Johnson, Mark; Jensen, Atle; Gundersen, Olav; Kristoffersen, Yngve; Babanin, Alexander; Tedesco, Paulina Souza; Christensen, Kai Håkon; Kristiansen, Martin; Hope, Gaute; Kodaira, Tsubasa; Martins de Aguiar, Victor Cesar; Taelman, Catherine Cecilia A; Quigley, Cornelius Patrick; Filchuk, Kirill; Mahoney, Andrew R. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-03)
      Variability in sea ice conditions, combined with strong couplings to the atmosphere and the ocean, lead to a broad range of complex sea ice dynamics. More in-situ measurements are needed to better identify the phenomena and mechanisms that govern sea ice growth, drift, and breakup. To this end, we have gathered a dataset of in-situ observations of sea ice drift and waves in ice. A total of 15 ...

    • Determination of the Dielectric Properties of Marine Surface Slicks Using Synthetic Aperture Radar 

      Quigley, Cornelius Patrick (Doctoral thesis; Doktorgradsavhandling, 2021-03-03)
      Over the course of the last three decades, Synthetic Aperture Radar (SAR) has proven itself to be an effective monitoring technology for marine applications. The clear benefits of using SAR as opposed to optical devices is that SAR is insensitive to cloud cover, lighting conditions and can also provide imagery to a high degree of resolution. Given these benefits, there is a large incentive to implement ...

    • Distinguishing Mineral Oil Slicks from Low Wind Areas using Rapid Repeat Synthetic Aperture Radar Imagery 

      Quigley, Cornelius Patrick; Johansson, Anna Malin Kristin; Jones, Cathleen Elaine; Holt, Benjamin (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-18)
      A method for differentiating marine oil slicks from radar-dark, low wind areas in open water using rapid repeat SAR imagery is reported. The study uses data acquired by the airborne UAVSAR L-band SAR instrument, imaging the Coal Oil Point seep field near Santa Barbara, California. Time-series of images from three different days are analyzed, all containing both verified oil slicks and low wind zones. ...

    • An investigation on the damping ratio of marine oil slicks in synthetic aperture radar imagery 

      Quigley, Cornelius Patrick; Johansson, Malin; Jones, Cathleen Elaine (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-12)
      The damping ratio has recently been used to indicate the relative internal oil thickness within oil slicks observed in synthetic aperture radar (SAR) imagery. However, there exists no well-defined and evaluated methodology for calculating the damping ratio. In this study, we review prior work regarding the damping ratio and outline its theoretical and practical aspects. We show that the most often ...