RADARSAT data have a potential role for coastal pollution monitoring. This study presents a new approach to detect and forecast oil slick trajectory movements. The oil slick trajectory movements is based on the tidal ...RADARSAT data have a potential role for coastal pollution monitoring. This study presents a new approach to detect and forecast oil slick trajectory movements. The oil slick trajectory movements is based on the tidal current effects and Fay's algorithm for oil slick spreading mechanisms. The oil spill trajectory model contains the integration between Doppler frequency shift model and Lagrangian model. Doppler frequency shift model implemented to simulate tidal current pattern from RADARSAT data while the Lagrangian model used to predict oil spill spreading pattern. The classical Fay's algorithm was implemented with the two models to simulate the oil spill trajectory movements.The study shows that the slick lengths are effected by tidal current V component with maximum velocity of 1.4 m/s. This indicates that oil slick trajectory path is moved towards the north direction. The oil slick parcels are accumulated along the coastline after 48 h. The analysis indicated that tidal current V components were the dominant forcing for oil slick spreading.展开更多
Multi-frequency C and L bands in the TOPSAR data have been utilized to reconstruct three-dimensional(3-D)bathymetry pattern.The main objective of this study is to utilize fuzzy arithmetic to reduce the errors arising ...Multi-frequency C and L bands in the TOPSAR data have been utilized to reconstruct three-dimensional(3-D)bathymetry pattern.The main objective of this study is to utilize fuzzy arithmetic to reduce the errors arising from speckle in synthetic aperture radar(SAR)data when constructing ocean bathymetry from polarized SAR data.In doing so,two 3-D surface models,the Volterra algorithm and a fuzzy B-spline(FBS)algorithm,which construct a global topological structure between the data points,were used to support an approximation to the real surface.Volterra algorithm was used to express the non-linearity of TOPSAR data intensity gradient based on the action balance equation(ABC).In this context,a first-order kernel of Volterra algorithm was used to express ABC equation.The inverse of Volterra algorithm then performed to simulate 2-D current velocities from CVV and LHH band.Furthermore,the 2-D continuity equation then used to estimate the water depth.In order to reconstruct 3-D bathymetry pattern,the FBS has been performed to water depth information which was estimated from 2-D continuity equation.The best reconstruction of coastal bathymetry of the test site in Kuala Terengganu,Malaysia,was obtained with polarized L and C bands SAR acquired with HH and VV polarizations,respectively.With 10 m spatial resolution of TOPSAR data,bias of0.004 m,the standard error mean of 0.023 m,r2 value of 0.95,and 90%confidence intervals in depth determination was obtained with LHH band.展开更多
The paper explores a framework combining remote sensing and GIS-cellular automata(CA)concepts aimed at improving the modeling of unauthorized land use sprawl.Remote sensing data have been used in urban modeling and an...The paper explores a framework combining remote sensing and GIS-cellular automata(CA)concepts aimed at improving the modeling of unauthorized land use sprawl.Remote sensing data have been used in urban modeling and analysis,the use of high-resolution remote sensing data in assessing unauthorized development is quite unexplored.This work has demonstrated systematic combination utilization of geospatial analyses tools to acquire a new level of information to enable urban modeling and sprawl analysis in assisting urban sustainable management.In this study,Kuantan city,Malaysia was selected in simulation of the unauthorized land use with CA concept for a period of 15 years(20002015),with main input time-series land use observation from 1995 to 2005.The 2000 and 2005 land use input was also used as calibrated and test assessment of the simulation.The results show excellent agreement between in-situ changes of the unauthorized land use classes and the corresponding simulated classes within the same periods.In conclusion,CA model can lead to new levels of understanding of how urban areas grow and change as in view of digital earth aspiration.展开更多
文摘RADARSAT data have a potential role for coastal pollution monitoring. This study presents a new approach to detect and forecast oil slick trajectory movements. The oil slick trajectory movements is based on the tidal current effects and Fay's algorithm for oil slick spreading mechanisms. The oil spill trajectory model contains the integration between Doppler frequency shift model and Lagrangian model. Doppler frequency shift model implemented to simulate tidal current pattern from RADARSAT data while the Lagrangian model used to predict oil spill spreading pattern. The classical Fay's algorithm was implemented with the two models to simulate the oil spill trajectory movements.The study shows that the slick lengths are effected by tidal current V component with maximum velocity of 1.4 m/s. This indicates that oil slick trajectory path is moved towards the north direction. The oil slick parcels are accumulated along the coastline after 48 h. The analysis indicated that tidal current V components were the dominant forcing for oil slick spreading.
文摘Multi-frequency C and L bands in the TOPSAR data have been utilized to reconstruct three-dimensional(3-D)bathymetry pattern.The main objective of this study is to utilize fuzzy arithmetic to reduce the errors arising from speckle in synthetic aperture radar(SAR)data when constructing ocean bathymetry from polarized SAR data.In doing so,two 3-D surface models,the Volterra algorithm and a fuzzy B-spline(FBS)algorithm,which construct a global topological structure between the data points,were used to support an approximation to the real surface.Volterra algorithm was used to express the non-linearity of TOPSAR data intensity gradient based on the action balance equation(ABC).In this context,a first-order kernel of Volterra algorithm was used to express ABC equation.The inverse of Volterra algorithm then performed to simulate 2-D current velocities from CVV and LHH band.Furthermore,the 2-D continuity equation then used to estimate the water depth.In order to reconstruct 3-D bathymetry pattern,the FBS has been performed to water depth information which was estimated from 2-D continuity equation.The best reconstruction of coastal bathymetry of the test site in Kuala Terengganu,Malaysia,was obtained with polarized L and C bands SAR acquired with HH and VV polarizations,respectively.With 10 m spatial resolution of TOPSAR data,bias of0.004 m,the standard error mean of 0.023 m,r2 value of 0.95,and 90%confidence intervals in depth determination was obtained with LHH band.
文摘The paper explores a framework combining remote sensing and GIS-cellular automata(CA)concepts aimed at improving the modeling of unauthorized land use sprawl.Remote sensing data have been used in urban modeling and analysis,the use of high-resolution remote sensing data in assessing unauthorized development is quite unexplored.This work has demonstrated systematic combination utilization of geospatial analyses tools to acquire a new level of information to enable urban modeling and sprawl analysis in assisting urban sustainable management.In this study,Kuantan city,Malaysia was selected in simulation of the unauthorized land use with CA concept for a period of 15 years(20002015),with main input time-series land use observation from 1995 to 2005.The 2000 and 2005 land use input was also used as calibrated and test assessment of the simulation.The results show excellent agreement between in-situ changes of the unauthorized land use classes and the corresponding simulated classes within the same periods.In conclusion,CA model can lead to new levels of understanding of how urban areas grow and change as in view of digital earth aspiration.
