Download or read book Measurement of Ocean Wave Spectra Using a Ship mounted HF Radar written by and published by . This book was released on 1990 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: A promising alternative to in situ methods such as wave buoys for measuring ocean wave spectra is HF ground wave radar. This paper describes an algorithm used to extract the nondirectional wave-height spectrum from the backscatter return of a stationary ship- or rig-mounted radar employing an omnidirectional antenna for both transmission and reception. To test the effectiveness of the algorithm, its estimates are compared to those of a WAVE-TRACK buoy using data collected onboard CFAV Quest during 1988.

Download or read book Status of HF Radars for Wave Height Directional Spectral Measurements written by Donald E. Barrick and published by . This book was released on 1982 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: This manuscript is a concise review of the status of high-frequency (HF) radars for measuring various descriptors of the ocean wave-height directional spectrum. It is not intended as a historical account of the many developments and contributors to the subject over the past three decades, nor is it meant to develop the theory and techniques of HF radar in sufficient detail for planning HF radar programs. Finally, no attempt is made to review every MF/ HF experiment performed or analyzed, although several very clever techniques have been tried (e.g., bistatic arrangements, synthetic aperture systems, and balloon-borne antennas); rather, techniques are discussed that appear to have potential for practical, operational ocean monitoring. The next section reviews very briefly the principles of HF radar sea echo that make it possible to measure the wave-height directional spectrum. The section following discusses the capability and status of sky-wave (over-the-horizon) radar for making wide- area ocean surface measurements. The final section discusses the application of HF ground-wave radars to measuring the wave-height directional spectrum, both for coastal use and for deployment from offshore platforms or ships, and their accuracy. In all cases, the limitations as well as the advantages of HF radars are indicated.

Download or read book Inversion of the HF Radar Doppler Spectrum for Ocean Wave Measurement written by Lucy Rhiannon Wyatt and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Remote Sensing of the Directional Ocean Wave Spectra Using HF Backscatter Radar written by Abdelrahman M. Elabdalla and published by . This book was released on 1982 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of Atmospheric and Oceanic Technology written by and published by . This book was released on 1997 with total page 858 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proposal to Demonstrate an HF Radar System for Measuring the Ocean wave Directional Spectrum from Offshore Platforms written by and published by . This book was released on 1981 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The High Frequency Surface Wave Radar Cross Section for Ocean Swell written by Chengxi Shen and published by . This book was released on 2013 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book SSC written by United States. Ship Structure Committee and published by . This book was released on 1997 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Prospects for Operational HF Radar Measurements of the Ocean Wave Directional Spectrum written by Lucy Rhiannon Wyatt and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Errors in HF Radar Ocean Current Measurements written by Tatsuya Najima and published by . This book was released on 2005 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Algorithm for the Extraction of Ocean Wave Spectra from Narrow Beam HF Radar Backscatteer written by Randy Keith Howell and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An algorithm is developed and tested to interpret ocean wave spectra from the backscatter return of one or more narrow beam HF radars. The basis of this measurement is the inversion of the integral equation representing the second order radar cross section of the ocean surface (Barrick and Lipa, 1986; Srivastava, 1984; Walsh and Howell, 1990). This equation is numerically inverted by approximating it as a matrix equation and factorizing the resultant kernel matrix using a singular value decomposition to obtain its pseudo-inverse. -- Due to the limitations of the assumption used to linearize the integral equation, the proposed inversion algorithm is best suited for general use at high HF frequencies (≈ 20 to 30 MHz). However, this algorithm may still be applied for the crucial task of monitoring large sea state conditions at even very low HF frequencies (

Download or read book Measurement of Sea Scatter and Buoy Tracks at Long Ranges by High Resolution OTH B Radar written by Joseph W Maresca (Jr) and published by . This book was released on 1975 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the final report on a two-year contract entitled 'Measurement of Sea Scatter and Buoy Tracks at Long Ranges by High-Resolution OTH-B Radar.' The Wide Aperture Research Facility (WARF), a high-resolution skywave high-frequency (HF) radar located in central California, was used to obtain remote measurements of the ocean wave spectrum, overwater wind velocity, and ocean currents in the North Pacific Ocean. The ocean currents were determined by tracking drogued and undrogued drifting buoys carrying a low-power HF repeater. Three types of sea backscatter Doppler spectra were recorded to determine the ocean wave spectrum and the wind velocity: (1) Backscatter from wide areas of the ocean to develop techniques for mapping wind fields, (2) Backscatter from limited areas near research vessels, Navy ships, and ships of opportunity to correlate the observed and radar-measured wind field; (3) Long-term coherent samples of backscatter for high-resolution off-line processing to derive the ocean wave spectrum.

Download or read book Advanced Ocean Surface Measurements with HF Radar written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: HF surface wave radar for ocean wave and current measurements began with collaborative work at Stanford University and Scripps Institution of Oceanography in the late 1960's. Two of the participants in this project (Drs. Teague and Vesecky) have worked with HF radar observations of the ocean since these early experiments. Under this grant a new HF radar design was begun and some prototype construction completed. This work led to construction of a full scale prototype that is now being tested over Monterey Bay, California from a field site kindly provided at the Long Marine Laboratory of the University of California at Santa Cruz. Initial results, including radial current field maps at four frequencies and variations of currents with time, were presented at the American Geophysical Union Fall Meeting in San Francisco, December, 1996. This final report is a presentation of results under the funding from ONR grant N00014-94-1-0371. It contains an overview of the radar design and its implementation in hardware as well as some preliminary results on vertical shear in the surface current field over Monterey Bay CA.

Download or read book Coastal Ocean Dynamics Applications Radar written by Thomas Martin Georges and published by . This book was released on 1985 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Observation by HF Radar of the Phillips Resonance Mechanism for Generation of Wind Waves written by and published by . This book was released on 1980 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comparison of Wave Parameters and Spectra Between Wera Hf Radars and Tri axys Buoys written by Mei Wang and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To establish the credibility of surface wave measurements from two phased-array WERA HF (High Frequency) radars, SEACOOS (SouthEast Atlantic Coastal Ocean Observing System) funded the Mini-Waves experiment from March to May, 2005. For this study, the surface wave parameter (significant wave height) and directional wave spectrum obtained from two WERA radars were compared with those obtained from two Tri-Axys buoys during the same period. The Wyatt (1990) method was used to obtain the directional wave spectra, and significant wave heights were obtained by integrating the directional wave spectra over all directions and the selected frequency band. The SWAN (Simulating WAve Nearshore) directional wave model was used to evaluate the comparison results between WERA radars and buoys. There was a good agreement between WERA radars and Tri-Axys buoys when the echo-Doppler spectrum had a high 2nd-order SNR (signal-to-noise) ratio. The measurements didn2t agree in low sea states when the echo-Doppler spectrum had a lower SNR. Also, strong horizontal current shear caused by Florida Current (FC) had an effect on wave propagation direction. To improve the quality of WERA radar wave measurements, a longer sampling interval (10-minute interval) and procedures to remove the effect of RFI are needed.

Download or read book Measuring Ocean Waves written by NATIONAL RESEARCH COUNCIL WASHINGTON DC MARINE BOARD. and published by . This book was released on 1981 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: Operational Needs for Wave Data; Research Needs for Wave Data; Survey of Remote Sensing Techniques for Wave Measurement; Remote Sensing of Ocean Waves by Surface Contour Radar; The Use of Synthetic Aperture Radar (SAR) to Measure Ocean Gravity Waves; Status of HF Radars for Wave-Height Directional Spectral Measurements; Aircraft and Satellite Measurement of Ocean Wave Directional Spectra Using Scanning-Beam Microwave Radars; Review of Wave Measurement Using In Situ Systems; Wave Measurements Using Surface-Mounted Instruments; Pitch-Roll Buoy Wave Directional Spectra Analysis; Subsurface Wave-Measuring Systems; Wave-Measurement Technology in the 1980s; Workshop Sessions.