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Robust Extraction of Shoreline by Integrating Robust Extraction of Shoreline by Integrating DubaiSat1 Multispectral Imagery and a DubaiSat1 Multispectral Imagery and a
Coastal Terrain Model (CTM)Coastal Terrain Model (CTM)
Tarig A. Ali, PhDAssociate Professor, Dept. of Civil Engineering
American University of Sharjah, UAE
Geospatial World Forum - Rotterdam, Netherlands
May 13-16, 2013
Flow Chart of Technical Approach
Study Area: Al-Ras area, Dubai, UAE
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 region of 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
MS image-derived Shoreline segment
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.
Flowchart of Building a CTM using ESRI’s TDS
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
Thank youThank you