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Robust Extraction of Shoreline by Integrating DubaiSat1 Multispectral Imagery and a Coastal Terrain Model (CTM ). Tarig A. Ali, PhD Associate Professor, Dept. of Civil Engineering American University of Sharjah, UAE. Flow Chart of Technical Approach. Study Area: Al-Ras area, Dubai, UAE.
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Robust Extraction of Shoreline by Integrating DubaiSat1 Multispectral Imagery and a Coastal Terrain Model (CTM) Tarig A. Ali, PhD Associate Professor, Dept. of Civil Engineering American University of Sharjah, UAE Geospatial World Forum - Rotterdam, Netherlands May 13-16, 2013
DubaiSat1 Image of the study area • Multispectral (R, G, B) • Spatial Resolution: 5m • Acquisition date: 12 Nov, 2011 • Image was enhanced by applying a median filter followed by a HPF “basic: -1s and 8”. • Advantages of the median LPF: preserves edges while removing impulse noise and yet help to avoid excessive smoothing.
Surface-Leaving Radiance in the Red Band of DubaiSat1 Image Note the high absorption in the red regionof the electromagnetic spectrum of the Image
Classification of DubaiSat1 image • The Iterative Self-Organizing Data Analysis Technique Algorithm (ISODATA) was used in the classification. Geospatial World Forum - Rotterdam, Netherlands May 13-16, 2013
Classification techniques • ISODATA algorithm takes maximum advantage of spectral variability in an image. • “Iterative Self-Organizing Data Analysis Technique” • Parameters : • N - the maximum number of clusters that you want • T - a convergence threshold and • M - the maximum number of iterations to be performed. Geospatial World Forum - Rotterdam, Netherlands May 13-16, 2013
Data used to create the CTM of the study area • The data set comprised of: • 3D bare earth mass points • bathymetric contour data: 10-m interval (surveyed in late September 2011). • LIDAR acquisition date: week of 20 November, 2011 • LiDAR system: Leica LS-50 system integrated with IMU & GPS. • Positional accuracy: RMSE = 0.23-m. • Vertical accuracy: RMSE = 0.10-m in open areas. • Spatial Reference: Dubai Local Transverse Mercator (DLTM) - WGS_84.
Costal Terrain Model (CTM) of the study area Spatial Resolution: 10m
Fusion of the MS Image based Shoreline, CTM, and Aerial Image Outcome: Refined shoreline
Concluding Remarks • Extraction of shoreline by fusing DubaiSat1 MS imagery, DTM, and an aerial image was successful . • Issues need further investigation: • Effect of the difference in spatial resolution between the MS image and the DTM • Effect of the vectorization of the shoreline derived from DubaiSat1 MS imagery. Geospatial World Forum - Rotterdam, Netherlands May 13-16, 2013