Download or read book Measurements of Coastal Currents Using a Ship Based VHF Radar System written by and published by . This book was released on 1994 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The University of Miami Ocean Surface Current Radar (OSCR) is a pulsed radar which utilizes a Yagi transmit antenna and a phased, line array receive antenna. In its VHF (50 MHz) mode of operation, the system has a range of 12 km and a resolution of 250 m. The Bragg resonant wavelength is 3 m. In December 1993, one of two OSCR VHF sites was configured aboard the 50 m research vessel COLUMBUS ISELIN, anchored in a four-point mooring 5 km from the second site on Key Biscayne, FL. A six channel accelerometer system was used to obtain ship motion measurements. The purpose of this experiment was an initial evaluation of using an OSCR type system to map nearshore coastal currents from a ship. Our results show that high quality vector current maps can be obtained provided that the motions of the support platform are moderately restrained and that the system is mounted so as to avoid superstructure effects. During our experiment, we have also shown the validity of these maps through comparisons with shore based measurements, known tidal flows and drifter observations. The capability to deploy an OSCR type system offshore leads to the potential for wide area, long term, real time monitoring of nearshore coastal currents. This potential would be useful in many coastal survey operations. The capability also leads to the potential for rapid change in the area of coverage via moving the locations of the support platforms. This potential would be useful in predicting the trajectories of nearshore spills of oil and other hazardous materials. VHF Radar, Surface currents, Coastal currents, Radar backscatter, Remote sensing.

Download or read book VHF Radar Measurements of Ocean Surface Currents from a Moving Ship written by and published by . This book was released on 1995 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shore-based, high frequency (HF) and very high frequency (VHF) radar systems for measuring ocean surface currents have been well detailed in the literature. The use of these systems has been limited to coastal ocean applications since both of the required radar sites must be positioned ashore. To relieve the geometric constraints imposed by two shore sites and allow coverage of more coastal areas, necessitates at least one sea-based system (Skop et al., 1994). Reducing the number of required sites to one increases the ocean area that can be measured. The feasibility of using a single, VHF radar system based on a moving ship for both near shore and deep water area coverage is the subject of this report. In December 1993 and July 1994 a near shore, ship-based data set was taken off the east coast of Key Biscayne, Florida, with overlapping coverage by a shore-based site. The July 1994 experiment also saw deep water data sets acquired as the ship described a square pattern to obtain overlapping grid coverage from the ship itself. The measurement and reduction of ship-induced contamination in the returned Doppler spectra are detailed. By combining ship and shore radial data, two vector current maps off north and south Key Biscayne a obtained. Using the same methodology, the vectorization of the deep water radials produces two more vector current maps from on transmit-receive ship-based site. The deep water surface current maps are dominated by the high speed, northerly flowing Florida Current and are quite accurate. The Key Biscayne surface current maps are less accurate, being dominated by pseudo-currents that are introduced through GPS errors in ship position. These GPS errors lead to inaccurate calculations of the ship velocity and, hence, to inaccurate removal of the ship-induce Doppler currents from the measured currents. (MM).

Download or read book Measuring Ocean Currents written by Antony Joseph and published by Newnes. This book was released on 2013-08-12 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measuring Ocean Currents: Tools, Technologies, and Data covers all major aspects of ocean current measurements in view of the implications of ocean currents on changing climate, increasing pollution levels, and offshore engineering activities. Although more than 70% of the Earth is covered by ocean, there is limited information on the countless fine- to large-scale water motions taking place within them. This book fills that information gap as the first work that summarizes the state-of-the-art methods and instruments used for surface, subsurface, and abyssal ocean current measurements. Readers of this book will find a wealth of information on Lagrangian measurements, horizontal mapping, imaging, Eulerian measurements, and vertical profiling techniques. In addition, the book describes modern technologies for remote measurement of ocean currents and their signatures, including HF Doppler radar systems, satellite-borne sensors, ocean acoustic tomography, and more. Crucial aspects of ocean currents are described in detail as well, including dispersion of effluents discharged into the sea and transport of beneficial materials—as well as environmentally hazardous materials—from one region to another. The book highlights several important practical applications, showing how measurements relate to climate change and pollution levels, how they affect coastal and offshore engineering activities, and how they can aid in tsunami detection. Coverage of measurement, mapping and profiling techniques Descriptions of technologies for remote measurement of ocean currents and their signatures Reviews crucial aspects of ocean currents, including special emphasis on the planet-spanning thermohaline circulation, known as the ocean's "conveyor belt," and its crucial role in climate change

Download or read book Measurements of Near Surface Ocean Currents Using HF Radar written by Kenneth Laws and published by . This book was released on 2001 with total page 378 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 2003 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Springer Handbook of Atmospheric Measurements written by Thomas Foken and published by Springer Nature. This book was released on 2021-11-09 with total page 1761 pages. Available in PDF, EPUB and Kindle. Book excerpt: This practical handbook provides a clearly structured, concise and comprehensive account of the huge variety of atmospheric and related measurements relevant to meteorologists and for the purpose of weather forecasting and climate research, but also to the practitioner in the wider field of environmental physics and ecology. The Springer Handbook of Atmospheric Measurements is divided into six parts: The first part offers instructive descriptions of the basics of atmospheric measurements and the multitude of their influencing factors, fundamentals of quality control and standardization, as well as equations and tables of atmospheric, water, and soil quantities. The subsequent parts present classical in-situ measurements as well as remote sensing techniques from both ground-based as well as airborn or satellite-based methods. The next part focusses on complex measurements and methods that integrate different techniques to establish more holistic data. Brief discussions of measurements in soils and water, at plants, in urban and rural environments and for renewable energies demonstrate the potential of such applications. The final part provides an overview of atmospheric and ecological networks. Written by distinguished experts from academia and industry, each of the 64 chapters provides in-depth discussions of the available devices with their specifications, aspects of quality control, maintenance as well as their potential for the future. A large number of thoroughly compiled tables of physical quantities, sensors and system characteristics make this handbook a unique, universal and useful reference for the practitioner and absolutely essential for researchers, students, and technicians.

Download or read book Encyclopedia of Marine Science written by C. Reid Nichols and published by Infobase Publishing. This book was released on 2009 with total page 641 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents an illustrated, A-Z encyclopedia with more than 600 entries providing information on topics related to marine science.

Download or read book Coastal Ocean Observing Systems written by Yonggang Liu and published by Academic Press. This book was released on 2015-06-01 with total page 491 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coastal Ocean Observing Systems provides state-of-the-art scientific and technological knowledge in coastal ocean observing systems, along with guidance on establishing, restructuring, and improving similar systems. The book is intended to help oceanographers understand, identify, and recognize how oceanographic research feeds into the various designs of ocean observing systems. In addition, readers will learn how ocean observing systems are defined and how each system operates in relation to its geographical, environmental, and political region. The book provides further insights into all of these problem areas, offering lessons learned and results from the types of research sponsored and utilized by ocean observing systems and the types of research design and experiments conducted by professionals specializing in ocean research and affiliated with observing systems. Includes international contributions from individuals working in academia, management, and industry Showcases the application of science and technology in coastal observing systems Highlights lessons learned on partnerships, governance structure, data management, and stakeholder relationships required for successful implementation Provides insight into how ocean research transfers to application and societal benefit

Download or read book Real time Measurement of Wide area Near surface Ocean Current written by Samareh Attarsharghi and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Of all of the physical parameters of the ocean realm, the speed and direction of the movement of ocean water, otherwise referred to as ocean "current," is one of the most problematic to characterize. Currents influence the global climate, used for producing power, are crucial in determining the oil spill trajectories and ocean contaminant control, can either work against or with the movement of ships at sea and govern the movements of icebergs. Icebergs are a threat to offshore industries and marine transportations, particularly in places like the Northwest Atlantic, because of damages they can cause once they strike the oil platforms or ship hulls. They are steered by the near-surface current and not the surface current. Therefore, measurment of the real-time ocean currents at desired depths is valuable for the industries or researchers who are dealing with or studying the oceanographic data. Ocean current measurment methods that are currently being employed for ocean monitorings, are not able to measure the real-time current at certain desired depths over a larg area of the ocean. Thus, the existing current measurement methods need improvements. Limitations of the existing methods are as follows. Acoustic dopler current profilers (ADCP), are one of the most popular methods employed by most of the industries dealing with the oceanograghy. ADCPs are capable of measuring the current at any desired depth; however, their measurement method is of a point nature and they cannot measure an area averaged current data. Other techniques such as high frequency radio detecting and ranging systems (HF-RADAR) are also used to measure the surface currents (down to 15 m). These shore-based current meters with radio antenna, follow the same premise of the ADCP. In other words their measurement is dependant on the Doppler effect to determine the direction and velocity of the currents; however, they are capable of evaluating only the surface currents and not the near-surface currents (70-100 meter of depth is considered in this thesis as this is the depth oil structures are deployed in the Northwest Atlantic Ocean). Another group of instruments used for current measurement are floats and drifters which report their data to a centre device which is usually a satelite. The current data obtained with these instruments are fed into modeling systems, e.g. in (Chassignet, Hurlburt et al. 2006), for the ocean forcasting. The problems that exist with the available real-time current data from the satelite is that it is the very shallow current data (down to 15m that can be called surface). The data from other devices like floats is very sparse to include the horizontal information. Hence, Chassignet et al. use data assimilation of the past knowledge and ocean dynamics in order to predict the ocean features. Therefore, it is important to develop a method by which adequate data could be provided for the ocean prediction and modeling system. Thus, the focus of this thesis is on designing a method which is real-time and measures the near-surface current. On the other hand, energy suplies to the instruments in open water is limited as they work mainly rely on batteries and it is difficult to access the instruments in harsh condition to replace the batteries. Moreover, in cold regions the solar power is very limitted and thus using solar cells is not practical. Therefore, in order to measure the ocean current in real time, a novel method along with a sustainable architechture design is being proposed in this dissertation. The new method is based on transit time with the difference that in transit time method waves need to travel in both directions; up- and down-stream. But with a modification in the newly designed architecture; which is adding an extra node in the center of the network's cells, sound waves need to travel on only one direction. This helps with saving a great amount of energy and covering a larger area in comparison with the networks which are developed using transit time method. Experimental results as well as simulations verify that the new proposed method is both efficient and practical.

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 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 High frequency Radar Measurements of Coastal Ocean Surface Currents written by Daniel Martin Fernandez and published by . This book was released on 1993 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oceanography High Frequency Radar and Ocean Thin Layers Volume 10 written by Larry Atkinson and published by . This book was released on 1999 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: Partial contents include: (1) HF Radar Instruments, Past to Present; (2) Mapping Surface Currents in Monterey Bay with CODAR-type HF Radar; (3) The Coastal Jet: Observations of Surface Currents over the Oregon Continental Shelf from HF Radar; (4) Tidal and Wind-driven Currents from OSCR; (5) Larval Transport and Coastal Upwelling: an Application of HF Radar in Ecological Research; (6) Evolution of Bearing Determination in HF Current Mapping Radars; (7) Shipboard Deployment of a VHF OSCR System for Measuring Offshore Currents; and (8) Experience with Shipborne Measurements of Surface Current Fields by Radar.

Download or read book Measurement for the Sea written by Pasquale Daponte and published by Springer Nature. This book was released on 2022-01-24 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the history of humankind, the sea has always played a key role as a privileged medium for communication, commerce and contact among population centers. It constitutes an essential ecosystem, and an invaluable reservoir and source of food for all living beings. Therefore, its heath is a critical challenge for the survival of all humanity, particularly as one the most important environmental components targeted by global warming. Measuring and monitoring techniques are key tools for managing the marine environment and for supporting the Blue Economy. With this perspective, a series of annual international events, entitled Metrology for the Sea (MetroSea for short) was begun in 2017. Their increasing success inspired this book, which provides an anthology of tutorials dealing with a representative selection of topics of concern to a broad readership. The book covers two broad application areas, marine hydrography and meteorology, and then deals with instrumentation for measurement at sea. Typical metrological issues such as calibration and traceability, are considered, for both physical and chemical quantities. Key techniques, such as underwater acoustic investigation, remote sensing, measurement of waves and monitoring networks, are treated alongside marine geology and the monitoring of animal species. Economic and legal aspects of metrology for navigation are also discussed. Such an unparalleled wide vision of measurement for the sea will be of interest to a broad audience of scientists, engineers, economists, and their students.

Download or read book Oceanic Abstracts written by and published by . This book was released on 1995-05 with total page 814 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oceanography written by and published by . This book was released on 1997 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improvement of Geophysical Model Functions for Radar based Ocean Surface Currents Measurements written by Shadi Aslebagh and published by . This book was released on 2018 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: My objective in this research work is to improve the quality of ocean surface current measurements using synthetic aperture radars. I will do this by including an improved, physics-based model in the algorithm that inverts the radar data to estimate ocean currents. Although the ocean winds geophysical model functions used by scatterometers are mature, there is significant deficiency in knowledge of the ocean surface current geophysical model function; my research addresses this deficiency. In the first chapter of this thesis, I discuss the importance of ocean surface currents, and various techniques to measure them. Following that introduction, in chapter 2, I introduce the microwave radar system, which I used to collect microwave data for this research work. The corresponding flight experiments for microwave data collection are also described in this chapter. In chapter 3, the surface current estimation method is discussed and few samples of retrieved surface current components are presented. Chapter 4 introduces a physics-based Doppler model, M4S, which is used to improve the surface current geophysical model function. First, I run the model for different cases and compare the model’s outputs with radar measurements to evaluate the existing model. In chapter 5, in order to improve surface current geophysical model function, I incorporate model’s output to the geophysical retrieval algorithm and present the output of the retrieval algorithm. Eventually, in chapter 6, I will implement improvement to the model, which ultimately results in improvement of surface current geophysical model functions. Chapter 6 includes the results, discussions and suggestions for future work.