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Maged Marghany 《Journal of the Indian Society of Remote Sensing》2017,45(3):503-511
In this work, the genetic algorithm is utilised for automatic detection of oil spills under wind speed conditions larger than 20 ms?1. The procedure is implemented using sequences of RADARSAT-2 SAR ScanSAR Narrow single beam data acquired in the Gulf of Mexico. The study demonstrates that implementing crossover allows for generation of accurate oil spills pattern. This conclusion is confirmed by the receiver–operating characteristic (ROC) curve. The ROC curve indicates that the existence of oil slick footprints can be identified with the area under the ROC curve and the no-discrimination line of 85 %, which is greater than that of other surrounding environmental features. In conclusion, the genetic algorithm can be used as a tool for the automatic detection of oil spills and the ScanSAR Narrow single beam mode serves as an excellent sensor for oil spill detection and surveying under wind speed larger than 20 ms?1. 相似文献
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Groundwater exploration and modelling requires hydrological parameters and a large volume of hydrologic database. This study integrates remote sensing and geographic information system (GIS) to map and classify hydrological parameters indicates areas of groundwater recharge and discharge. Bivariate quadratic surfaces with moving window size of 5 × 5 were fitted to the digital elevation model and drainage basins, drainage network, topographic wetness index (TWI) and hydroforms were derived. The eight-direction algorithm (D8) that determines in which neighbouring pixel any water in a central pixel will flow naturally was used to delineate drainage basin and drainage network in the study area. The TWI was used to quantify the effect of local topography on hydrological processes and for modelling soil moisture. The results indicate the presence of intensive of stream network (1336 km2), wettest zones and accumulation zones (63.99 km2) within Wadi Bih, the UAE and Wadi Khasb, Oman, suggesting regional recharge. 相似文献
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Maged Marghany 《Journal of the Indian Society of Remote Sensing》2004,32(2):185-198
This paper presents the application of the velocity bunching model to detect the wave spectra pattern. We have developed the
azimuth cut-off model which is estimated from the velocity bunching theory to model out the significant wave height. The velocity
bunching model utilized two ERS-1 images (First European Remote Sensing Satellite). These two ERS-1 images have been acquired
with the different monsoon periods. Several steps have been used to simulate the significant wave height from the velocity
bunching model, these were: the real ocean wave spectra simulated from the in situ wave data, and the SAR wave spectra, extracted
by applying two-dimensional Fourier transform (2-DFFT). Finally, the significant wave height was estimated based on the azimuth
cut-off arising from the velocity bunching model. Two hypotheses were established in modelling the wave spectra from the SAR
images: (i) azimuth cut-off was based on velocity bunching, which has been used to model the significant wave height with
high accuracy, and (ii) velocity bunching model has been used to map the SAR wave spectra into ocean wave spectra. In the
present study, a specific ERS-1 images of the South China Sea has been considered. No significant differences were found between
the velocity-bunching model and ocean wave spectra model where ERS-1 wave spectra has been found to be dominated by the azimuth
fall-off effects. Furthermore, the velocity bunching model produced wave spectra pattern approximately closed to the real
ocean wave compared to the SAR wave spectra. The highest rate of r2 (0.69) occurred when the significant wave height increased. It has been concluded that the velocity bunching model could
be used as the best fit model for estimating the significant wave height traveled along the azimuth direction. 相似文献
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DInSAR technique for three-dimensional coastal spit simulation from radarsat-1 fine mode data 总被引：1，自引：0，他引：1
Maged Marghany 《Acta Geophysica》2013,61(2):478-493
This work presents a new approach to 3D spit simulation using differential synthetic aperture interferometry (DInSAR). In doing so, conventional DInSAR procedures are implemented to three repeat passes of RADARSAT-1 SAR fine mode data (F1). Further, a new application of using fuzzy B-spline algorithm is implemented with phase unwrapping technique. The study shows that the performance of DInSAR method using fuzzy B-spline is better than the DInSAR technique, which is validated by the coefficient of determination r 2 of 0.96, probability p of 0.002, and accuracy (RMSE) of ± 0.034 m, with 90% confidence intervals. In conclusion, integration of fuzzy B-spline with phase unwrapping produces an accurate 3D coastal geomorphology reconstruction. 相似文献
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TOPSAR wave spectra model and coastal erosion detection 总被引：2，自引：0，他引：2
Maged Mahmoud Marghany 《International Journal of Applied Earth Observation and Geoinformation》2001,3(4):357
This paper presents work done utilizing TOPSAR data to detect shoreline change along the Terengganu coast (Malaysia). TOPSAR data were used to extract information on wave spectra. This wave spectra information was then used to model shoreline changes by investigating the wave refraction patterns. From these patterns, the volume transport at several locations was estimated. The shoreline change model developed was designed to cover a 20 km stretch of shoreline of Kuala Terengganu. The model utilized data from aerial photographs, TOPSAR data and ground truth data. The location of sedimentation and erosion along the shoreline of Kuala Terengganu was estimated. The wave spectra extracted from TOPSAR data showed wavelengths ranging from 20 m to 175 m. The main direction of the waves given by the spectra was from the northeast. The wave refraction patterns varied, showing both convergence and divergence, indicating erosion and sedimentation locations, respectively. A comparison between the TOPSAR shoreline change model and aerial photographs and ground truth data showed a significant relationship. Finally, the regression model showed that erosion occurred particularly at Sultan Mahmed Airport, at a rate of −1.5 m/year. The maximum rate of sedimentation along the 20 km stretch was 1 m/year. 相似文献
9.
Abdulrasoul M. Al-Omran Mohammed A. Mousa Maged M. AlHarbi Mahmoud E. A. Nadeem 《Arabian Journal of Geosciences》2018,11(4):79
Fifty groundwater samples were collected from Al-Hasa to analyze the pH, electrical conductivity (EC, dS m?1), total dissolved solids (TDS), major anions (HCO3?, CO32?, Cl?, SO42?, and NO3?), major cations (Ca2+, Mg2+, Na+, and K+), and total hardness. The analyzed data plotted in the Piper, Gibbs, and Durov diagrams, and water quality index (WQI) were calculated to evaluate the groundwater geochemistry and its water quality. The results reveal that most of the investigated samples are Ca2+, Mg2+, SO42?, Cl? and Na+, and HCO3? water types using the Piper diagram. Na+?>?Ca2+?>?Mg2+ are the dominant cations, while Cl??>?HCO3??>?SO42??>?CO32? are the dominant anions. Sodium adsorption ratio (SAR) values varied from 0.79 to 10; however, the Kelly ratio (KR) ranged between 0.1 and 2.2. The permeability index (PI) showed that well water is suitable for irrigation purposes with 75% or more of maximum permeability. The US salinity diagram revealed that the water quality classes of studied waters were CIII-SI, CIII-SII, and CIV-SII, representing height hazards of salinity and medium- to low-sodium hazard. The water quality index (WQI) results indicated that total dissolved solids are out of the drinking water standard limits in Saudi Arabia. The WQI revealed that 38% of the studied wells were considered as poor water (class III), 52% are found as very poor water class (IV), and 10% are unsuitable water for drinking class (V). 相似文献
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