Share

Using Ship Wake Patterns to Evaluate Sar Ocean Wave Imaging Mechanisms

1985 Artificial satellites
Download Using Ship Wake Patterns to Evaluate Sar Ocean Wave Imaging Mechanisms PDF Online Free

Author :
Release : 1985
Genre : Artificial satellites
Kind : eBook
Book Rating : /5 ( reviews)

GET EBOOK


Book Synopsis Using Ship Wake Patterns to Evaluate Sar Ocean Wave Imaging Mechanisms by : R. R. Hammond

Download or read book Using Ship Wake Patterns to Evaluate Sar Ocean Wave Imaging Mechanisms written by R. R. Hammond. This book was released on 1985. Available in PDF, EPUB and Kindle. Book excerpt: The Joint Ocean Wave Investigation Project (JOWIP) was conducted to evaluate the detectability of ocean wave structures on imaging synthetic aperture radar (SAR). This project used Kelvin surface ship wake patterns generated under controlled and well documented surface environmental conditions to isolate SAR image parameters. Use of waves of known wavelength and direction provide the opportunity to evaluate the SAR contribution to ocean wave forecasting. SEASAT-like images made with L-band SAR are presented: (1) to suggest how ship-generated surface roughness combines with the velocity-bunching mechanism in calm ocean areas to produce the unusually narrow wakes observed for azimuth-traveling ships on SEASAT images; and (2) to estimate conditions under which SAR image modulation mechanisms can be expected to produce wake images. A method is described for using the Kelvin transverse ship wake wave component to quantitatively evaluate the contributions of various SAR ocean wave imaging mechanisms. It makes use of the narrow sector of surface roughness generated by a ship along its track to produce SAR images of the longest waves in its wake system on flat calm water.

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

1987
Download SAR (Synthetic Aperture Radar) Imaging of Ship Wakes in the Gulf of Alaska PDF Online Free

Author :
Release : 1987
Genre :
Kind : eBook
Book Rating : /5 ( reviews)

GET EBOOK


Book Synopsis SAR (Synthetic Aperture Radar) Imaging of Ship Wakes in the Gulf of Alaska by : Omar H. Shemdin

Download or read book SAR (Synthetic Aperture Radar) Imaging of Ship Wakes in the Gulf of Alaska written by Omar H. Shemdin. This book was released on 1987. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Radar Imaging of the Ocean Waves

2008-09-15 Science
Download Radar Imaging of the Ocean Waves PDF Online Free

Author :
Release : 2008-09-15
Genre : Science
Kind : eBook
Book Rating : 517/5 ( reviews)

GET EBOOK


Book Synopsis Radar Imaging of the Ocean Waves by : Mikhail B. Kanevsky

Download or read book Radar Imaging of the Ocean Waves written by Mikhail B. Kanevsky. This book was released on 2008-09-15. Available in PDF, EPUB and Kindle. Book excerpt: This book is dedicated to studying the ocean with radar tools, in particular, with space radars. Being intended mainly for the scientists preoccupied with the problem (as well as senior course students), it concentrates and generalizes the knowledge scattered over specialized journals. The significant part of the book contains the results obtained by the author. Systematically collects and describes the approaches used by different laboratories and institutions Deals with the physics of radar imagery and specifically with ocean surface imagery Useful for students and researchers specializing in the area of ocean remote sensing using airborne or space-borne radars, both SAR and RAR

Ocean and Ship Wave Modification by a Surface Wake Flow Pattern

1988
Download Ocean and Ship Wave Modification by a Surface Wake Flow Pattern PDF Online Free

Author :
Release : 1988
Genre :
Kind : eBook
Book Rating : /5 ( reviews)

GET EBOOK


Book Synopsis Ocean and Ship Wave Modification by a Surface Wake Flow Pattern by : O. M. Griffin

Download or read book Ocean and Ship Wave Modification by a Surface Wake Flow Pattern written by O. M. Griffin. This book was released on 1988. Available in PDF, EPUB and Kindle. Book excerpt: Ocean surface waves are altered by interactions with mean and fluctuating surface currents. These waves may be ambient or ship-generated, or may be a combined system produced by both sources of generation. An important wave-current interaction is caused by the interaction of the waves with the surface wake produced by the passage of a surface ship. Remote observations of a ship wake using synthetic aperture radar (SAR) show distinct features such as a dark trailing centerline region and bright-line images aligned at some angle to the ship's path. The dark region of relatively low radar backscatter is usually associated with a 'dead winter' region which is relatively devoid of short wave components, while the bright line feature suggests a region of enhanced radar return within the apparent angular confines of the ship's Kelvin wave pattern. In this report the interactions of ship generated Kelvin waves and ambient waves with the momentum wake of a surface vessel are studied to assess the effectiveness of the momentum wake in the generation of these remotely-observed features. Other factors such as the limiting wave steepness at the onset of wave breaking also are considered. Keywords: Ocean waves, Wake detection, Marine hydrodynamics, Wake, Ship waves. (JHD).

The Simulation of the SAR Image of a Ship Wake

1991
Download The Simulation of the SAR Image of a Ship Wake PDF Online Free

Author :
Release : 1991
Genre :
Kind : eBook
Book Rating : /5 ( reviews)

GET EBOOK


Book Synopsis The Simulation of the SAR Image of a Ship Wake by :

Download or read book The Simulation of the SAR Image of a Ship Wake written by . This book was released on 1991. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes a computer simulation of L-band synthetic aperture radar (SAR) images of surface-ship wakes and compares the simulation results to actual satellite-borne SAR imagery. The model used in the simulation accounts for both the disturbance produced in the water by the moving ship and the influence of the background sea. The radar scatter from the wake is modelled using the Bragg mechanism. A two-scale model of the sea surface is employed which assumes that the small-wavelength Bragg waves are modulated by the larger scale ambient sea & wake fluctuations. Several components of the wake are modelled: the ambient waves, the Kelvin wake, and the turbulent wake.

You may also like...