A5050788165- Ocean Waves and Remote Sensing
- Oceanographic and Atmospheric Processes
- Coastal and Marine Dynamics
- Arctic and Antarctic ice dynamics
- Tropical and Extratropical Cyclones Research
- Underwater Acoustics Research
- Radar Systems and Signal Processing
- Geophysics and Gravity Measurements
- Maritime Navigation and Safety
- Target Tracking and Data Fusion in Sensor Networks
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Wind Energy Research and Development
- Marine and coastal ecosystems
- Methane Hydrates and Related Phenomena
- Offshore Engineering and Technologies
- Aeolian processes and effects
- Oil Spill Detection and Mitigation
- Meteorological Phenomena and Simulations
- Underwater Vehicles and Communication Systems
- Advanced SAR Imaging Techniques
- Ship Hydrodynamics and Maneuverability
- Marine and environmental studies
- Climate variability and models
- Adventure Sports and Sensation Seeking
- Aerospace Engineering and Energy Systems
Helmholtz-Zentrum Hereon
2015-2024
Norsk Hydro (Germany)
2002-2024
Coastal Impact
2006-2019
Philips (United Kingdom)
2019
University of Miami
2005-2018
North Atlantic Treaty Organization
2015
Memorial University of Newfoundland
2015
NATO Centre for Maritime Research and Experimentation
2009-2014
Center For Remote Sensing (United States)
2005-2013
Oceanography Society
2013
The precision images (PRI) of the synthetic aperture radars (SAR) on board European Remote Sensing Satellites ERS‐1 and ERS‐2 are used to derive mesoscale wind fields over ocean. For calculation speed C‐band model (CMOD4) is used, which was originally developed by Stoffelen Anderson [1993] for Space Agency (ESA) from measurements scatterometer (SCAT). In case ERS‐1/2 SAR CMOD4 compute normalized radar backscatter cross section (NRCS) incidence angle beam, both computed SAR.PRI data. third...
The high spatial resolution and large coverage of satellite-based synthetic aperture radars (SAR) offers a unique opportunity to derive mesoscale wind fields over the ocean surface, providing near shore. For this purpose, algorithms were developed tested using ScanSAR aboard Canadian satellite RADARSAT-1, operating at C-band with horizontal polarization in transmit receive. Wind directions are extracted from wind-induced streaks visible on most SAR images. speeds derived normalized radar...
In the last decades, great interest has been directed toward low-power high-frequency (HF) surface-wave radars as long-range early warning tools in maritime-situational-awareness applications. These sensors, developed for ocean remote sensing, provide an additional source of information ship detection and tracking, by virtue their over-the-horizon coverage capability continuous-time mode operation. Unfortunately, they exhibit many shortcomings that need to be taken into account, such poor...
High Frequency radar (HFR) is a land-based remote sensing instrument offering unique insight to coastal ocean variability, by providing synoptic, high frequency and resolution data at the atmosphere interface. HFRs have become invaluable tools in field of operational oceanography for measuring surface currents, waves winds, with direct applications different sectors an unprecedented potential integrated management zone. In Europe, number HFR networks has been showing significant growth over...
The global availability of synthetic aperture radar (SAR) wave mode data from the European Remote Sensing (ERS) satellites ERS-1 and ERS-2, as well ENVISAT, allows for investigation wind field over ocean on a continuous basis. For this purpose, 27 days ERS-2 SAR were processed, representing total 34310 imagettes size 10 km /spl times/5 km, available every 200 along satellite track. In paper, two methods retrieving speeds are presented validated, showing applicability ENVISAT alike retrieval....
These last decades spawned a great interest toward low-power high-frequency (HF) surface-wave (SW) radars for ocean remote sensing. By virtue of their over-the-horizon coverage capability and continuous-time mode operation, these sensors are also effective long-range early warning tools in maritime situational awareness applications providing an additional source information target detection tracking. Unfortunately, they exhibit many shortcomings that need to be taken into account, proper...
Abstract. The Coastal Observing System for Northern and Arctic Seas (COSYNA) was established in order to better understand the complex interdisciplinary processes of northern seas coasts a changing environment. Particular focus is given German Bight North Sea as prime example heavily used coastal area, Svalbard an coast that under strong pressure due global change.The COSYNA automated observing modelling system designed monitor real-time conditions provide short-term forecasts, data, data...
Abstract. Hurricane-force wind speeds can have a large societal impact and in this paper microwave C-band cross-polarized (VH) signals are investigated to assess if they be used derive extreme wind-speed conditions. European satellite scatterometers excellent hurricane penetration capability at C-band, but the vertically (VV) polarized become insensitive above 25 m s−1. VV VH backscatter from RADARSAT-2 SAR imagery acquired during severe events were compared collocated SFMR measurements by...
Significant wave height is one of the most important parameters for characterizing ocean waves and essential coastal protection, shipping, as well off shore industry operations. Within this paper, a robust method introduced retrieving significant heights from Doppler speed measurements acquired with coherent-on-receive marine radar. The velocity caused by surface scattering in line site To huge extent its periodic component induced orbital motions associated waves. proposed methodology based...
High Frequency Radar (HFR) technology refers to land based remote sensing instruments capable of measuring surface currents and ocean waves at ranges up 200 km or more. HFR is widely acknowledged as a cost-efficient tool monitor coastal regions has potential use all over the world. Globally, number stations steadily increasing. Regional networks provide real-time data in support operational activities such search rescue operations, fast response case maritime accidents spill pollutants,...
AbstractThis paper discusses an algorithm designed to retrieve high-resolution wind fields from scanning synthetic aperture radar (ScanSAR) data acquired on board the Canadian satellite RADARSAT-1. The ScanSAR operates at C-band with horizontal polarization. directions are extracted wind-induced streaks, e.g., atmospheric boundary layer rolls or shadowing, which approximately in line mean direction near ocean surface. speeds derived normalized cross section (NRCS) and image geometry of...
A global dataset of complex synthetic aperture (SAR) images is processed from wave mode raw data acquired by the ERS-2 satellite. Using these data, different algorithms for wind and measurements recently developed in view future ENVISAT ASAR are analyzed on a statistical basis. Different aspects SAR processing with DLR processor BSAR discussed statistics parameters presented. Single-look (SLC) imagettes give opportunity to apply multilook techniques range as well azimuth. Such methods used...
The dependency of radar backscatter on the surface wind field is investigated using a nautical X‐band operating at grazing incidence and horizontal polarization in transmit receive. This resulted development an algorithm for retrieval from image sequences. consists two parts: In first part, directions are extracted wind‐induced streaks that line with mean direction. These visible temporal integrated images scales between 100 500 m. orientation determined local gradients, which derived...
A methodology for retrieving high-resolution ocean surface wind fields from satellite-borne synthetic aperture radar (SAR) data is introduced and validated. The algorithms developed are suited SAR data, which were acquired at the C band of either vertical (VV) or horizontal (HH) polarization in transmission reception. Wind directions extracted wind-induced streaks that visible images scales greater than 200 m. These very well aligned with mean direction. To extract orientation these streaks,...
Abstract This paper proposes a novel algorithm for retrieving the ocean wind vector from marine radar image sequences in real time. It is presented as an alternative to mitigate anemometer problems, such blockage, shadowing, and turbulence. Since modifies sea surface, proposed based on dependence of surface backscatter direction speed. retrieves using measurements range 200–1500 m. Wind directions are retrieved images integrated over time smoothed (averaged) space by searching maximum cross...
Video imagery of surface waves recorded from a small off-the-shelf quadcopter with self-stabilizing camera gimbal is analyzed to estimate the current field. The nadir looking acquires short image sequence, which geocoded Universal Transverse Mercator coordinates. resulting sequence used quantify characteristic parameters (wavelength, period, and direction) (0.1–1 m) in space time. This opens opportunity fit linear dispersion relation data thus monitor frequency shift induced by an ambient...
In this paper, the retrieval of sea surface current velocity from vertically polarized (V-pol) X-band marine radar data is presented. Three different methods, including iterative least square approach, normalized scalar product method, and polar shell algorithm, that have been used for horizontally are employed here. A comprehensive comparison performance three methods conducted using images collected by V-pol deployed on Forschungsplattformen in Nord- und Ostsee No. 3 (FINO3) offshore...
This paper presents a geophysical model function (GMF) that has been developed to describe the relation of ocean surface wind with normalized radar cross section (NRCS) at C-band polarization (cross-pol). Synthetic aperture (SAR) images have simultaneously collected copolarization (co-pol) and cross-pol moderate high speeds. Using SAR co-pol retrieved fields an uncertainty estimate speeds, dependencies NRCS are investigated respect wind, incidence angle, pairs. For speeds above 10 m/s, there...
Abstract The Lagrangian Submesoscale Experiment (LASER) involved the deployment of ~1000 biodegradable GPS-tracked Consortium for Advanced Research on Transport Hydrocarbon in Environment (CARTHE) drifters to measure submesoscale upper-ocean currents and their potential impact oil spills. experiment was conducted from January February 2016 Gulf Mexico (GoM) near mouth Mississippi River, an area characterized by strong currents. A Helmholtz-Zentrum Geesthacht (HZG) marine X-band radar (MR)...
Maritime surveillance (MS) is an important domain for many national and international institutions, agencies, bodies. In this context, the MS initiatives are aimed to enhance search rescue operations, provide effective response accidents disasters, monitor fisheries, prevent pollution support law enforcement defence. This means that it of vital importance generate real-time wide-area maritime operational pictures. However, issues at stake. For instance, deriving mission planning tools with...
Abstract The addition of offshore wind farms (OWFs) to stratified regions shelf seas poses an anthropogenic source turbulence, in which the foundation structures remove power from oceanic flow that is fed into turbulent mixing wake downstream. loss stratification within a single OWF structure observed for first time by means field observations, enable qualitative characterization disturbed These results are complemented with high‐resolution large eddy simulations four different strengths...
Abstract In February 2020, a 120‐km‐wide freshwater plume was documented by satellite and in situ observations near the Demerara Rise (7°N/54°W‐56°W). It initially stratified upper 10 m with content of 2–3 Amazon water distributed down to 40 m. On 2nd, ship transects indicate an inhomogeneous shelf structure propagating front its midst, whereas minimum salinity close 30 pss observed break on 5th. The eroded time but still 13–16 days later 33.3 value up 400 km from break. At this time, mixed...
The North Brazil Current (NBC) flows offshore of the mouth Amazon River and seasonally sheds anticyclonic rings (NBC rings) that propagate northwestward interact with plume (ARP). Mesoscale features have a high temporal variability is hard to monitor from current weekly monthly sea surface salinity (SSS) satellite fields. Novel SSS fields higher resolution analyzed together geostrophic currents, chlorophyll-a, wind speed in-situ data "Microbiomes cruise" on SV Tara in August–September 2021...
Mesoscale structures are key dynamical features of the ocean. They associated with a variety short-lived, small-scale processes—such as energy cascades, changes in ocean stratification, and modulation carbon oxygen uptake—that occur at submesoscales. In high latitudes, where mesoscale can span only tens kilometers, capturing submesoscale processes is especially challenging. To address this, extensive submesoscale-resolving, multiplatform experiments were conducted summers...