scholarly journals Visibility of River Plume Fronts with an X-Band Radar

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Satoshi Takewaka
Keyword(s):  
Wind Speed ◽  
Water Level ◽  
River Plume ◽  
Field Observations ◽  
Local Wind ◽  
Radar Images ◽  
Optical Images ◽  
X Band ◽  
Wave Heights ◽  
Radar Measurements

A land-based X-band radar was employed to observe river plume fronts at the mouth of the Tenryu River, Japan. Time-averaged radar images captured fronts extending offshore from the river’s mouth as bright streaks. Comparisons between satellite optical images and radar images confirm that streaky features in the radar image represent color river plume fronts. Further corroboration comes from field observations of water temperature, salinity, and turbidity conducted simultaneously with the radar measurements. When a survey ship crossed the front, the measured properties varied discontinuously, suggesting that water from the river and sea converged there and also that a downwards current was present. Variation of visibility of the fronts was assessed and compared with the rate of variation of water level and the wind speed and direction. The radar is able to image fronts when the water level is decreasing during ebb tide and the wind speed is over 3 m/s along shore. Surface ripple waves are generated by the local wind, and if they propagate across the front, wave heights increase, causing higher backscatter of the emitted radar beam. This observation gives further evidence on the imaging mechanism of river plume fronts with X-band radars in relation to wind direction.

scholarly journals RIP CURRENT OBSERVATION WITH X-BAND RADAR

2011 ◽  
Vol 1 (32) ◽  
pp. 43 ◽  
Author(s):  
Satoshi Takewaka ◽  
Taishi Yamakawa
Keyword(s):  
Rip Current ◽  
Rip Currents ◽  
Aerial Photos ◽  
Release Experiment ◽  
Radar Images ◽  
Optical Images ◽  
Current Observation ◽  
X Band ◽  
Radar Measurements ◽  
Research Institute

X-band radar measurements were conducted at the research pier HORS, of the Port and Airport Research Institute, located in Hasaki, Japan. Ensembles of original radar images over 17 minutes were processed to time-averaged radar images every hour, which were analyzed to estimate the intertidal morphology and occurrence of rip currents. Several streaks extending in the cross shore direction appear in the averaged images which resemble to a neck and head of a rip current captured often in aerial photos or video imageries. The natures of these characteristic patterns in the time-averaged image are investigated through comparisons between optical images, floater release experiment and statistic analyses on sea conditions.

Wind speed determination from X-band nautical radar images

2017 ◽  
Author(s):  
Xinlong Liu ◽  
Weimin Huang ◽  
Eric W. Gill
Keyword(s):  
Wind Speed ◽  
Radar Images ◽  
X Band

scholarly journals An improved algorithm for phase-resolved sea surface reconstruction from X-band marine radar images

2021 ◽  
Vol 7 (1) ◽  
pp. 97-114
Author(s):  
Victoria Zinchenko ◽  
Leonid Vasilyev ◽  
Svein Olav Halstensen ◽  
Yuming Liu
Keyword(s):  
Wave Theory ◽  
Linear Wave ◽  
Linear Dispersion ◽  
Radar Images ◽  
Modified Method ◽  
Reconstruction Methods ◽  
X Band ◽  
Marine Radar ◽  
Radar Measurements ◽  
Proposed Modification

AbstractWe present a modified methodology for phase-resolved surface wave reconstruction from incoherent X-band marine radar images. The method is based on the linear wave theory and uses the linear dispersion relation to extract the valuable signals associated with gravity waves. A parameter optimization of the proposed modification is performed based on simulated synthetic radar images. The quantitative comparisons in the accuracy of the standard and modified reconstruction methods are made for both simulated and real radar images. The correlation coefficient between reconstructed and true wave elevations is improved up to 0.9–0.92 for the present modified method from 0.69 to 0.74 for the standard method for the simulated sea surfaces. The wave spectra reconstructed from the real X-band radar measurements are in good agreement with those obtained from the independent point measurement by Miros RangeFinder for both unimodal and bimodal seas.

The research study in the convergence of the results of processing radar images Sentinel-1A with field observations of agricultural sites

2019 ◽  
Vol 950 (8) ◽  
pp. 52-58
Author(s):  
D.V. Mozer ◽  
Е.L. Levin ◽  
A.K. Satbergenova
Keyword(s):  
Satellite Remote Sensing ◽  
Satellite Images ◽  
Research Study ◽  
High Accuracy ◽  
Agricultural Fields ◽  
Field Observations ◽  
Radar Images ◽  
The Earth ◽  
Radar Satellite ◽  
Modern Technologies

The manuscript discusses how to monitor the condition of seedlings on agricultural fields planted with winter wheat, fodder maize and areas of fir forest located in the Freudenstadt district of Baden-Wuerttemberg in Germany. To solve the range of agricultural problems , they often use modern technologies such as satellite remote sensing of the Earth. The paper displays the monitoring results of the Sentinel-1A radar satellites scenes, as well as visual spectrum imagery of field observations are presented when leaving directly to terrain segments. The processing deployed data chain, consisting of 11 Sentinel-1A scenes acquired in the timefrane from March to November 2018. Specifically, the SNAP Sentinel Toolboxes software was used to process the radar satellite images Sentinel-1А, the. Based on the the research outcomes the Committee of Agriculture of the Freudenstadt district is able to predict the yield amount with high accuracy due to good data convergence. According to the study, the following three important problems can be resolved by means of Sentinel-1A imagery

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