SAR (Synthetic Aperture Radar) Imaging of Ship Wakes in the Gulf of Alaska

Abstract

Conclusions include: 1.) The half-angles associated with narrow-V wakes are consistent with first-order Bragg surface theory. 2) The decay rate along the bright arms of the narrow-V wake is consistent with a combined viscous and radiation decay of short surface wave with first-order Bragg wave lengths.3) Narrow-V wakes are observed in Sea States 1-3 at incidence angles less than or equal to 44 deg. The limitation is due to the noise threshold of the SAR system used. 4) The longest narrow-V wakes bright-arm observed is 12.0 km (31 deg. incidence angle) in Sea State 1, 3.9 km (44 deg incidence angle) in Sea State 2 and 4.3 km (24 deg incidence angle) in Sea State 3. In Sea State 4 no narrow-V wakes could be observed. 5) The turbulent wake (dark band between bright arms) is observed in Sea States 1-3 at incidence angles less than 53 deg. The limitations is due to the noise threshold in the SAR system used. 6) The longest turbulent wake length observed is 41 km (37 deg incidence angle) in Sea State 1, 4.5 km (35 deg incidence angle) in Sea State 2 and 5.5 km (24 deg incidence angle) in Sea State 3. No turbulent wake is observed in Sea State 4. Keywords: Synthetic aperture radar backscattering; Ocean surface waves; Deep mixed-layer marine environments; Deep water; Radar images

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1987
Accession Number
ADA186554

Entities

People

  • Omar H. Shemdin

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Backscattering
  • Boundary Layer
  • Data Analysis
  • Geography
  • Geometry
  • Group Velocity
  • Internal Waves
  • Jet Propulsion
  • Measurement
  • Plastic Explosives
  • Radar
  • Scattering
  • Surface Waves
  • Synthetic Aperture Radar
  • Temperature Gradients
  • Water
  • Waves

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Oceanography.