Document Type
Paper
Start Date
15-10-2024 11:05 AM
End Date
15-10-2024 11:40 AM
Abstract
This study focuses on the the development of a method to create Digital Elevation Models (DEMs) for forecasting coastal inundation, a critical tool in the face of rising sea levels and extreme weather events. The study utilizes oblique stereo imagery captured with non-metric cameras, focusing on the area adjacent to Horace Caldwell pier in Port Aransas, Texas. The methodology involves the strategic placement of two Amcrest Ultra4K non-metric cameras on an elevated structure at the pier entrance. These cameras, positioned 8 meters above the ground and 20 meters apart, capture images at varying nadir angles high oblique (65 degrees), oblique (45 degrees), and less oblique (35 degrees). The project addresses the challenge of generating accurate DEMs from oblique stereo images, a task complicated by the fact that most existing software and techniques are designed for vertical imagery. Our method employs Structure from Motion (SfM) using stereo oblique images and non-metric cameras mounted on a coastal pier to create the DEMs. Key to the methodology is the careful calibration and application of advanced image processing techniques suited for high oblique imagery. Image processing-based methods use include wavelet transform for enhanced feature matching and clarity enhance ment, as well as rectification and georeferencing within MATLAB and ArcGIS Pro environments, respectively, to maintain true to-life spatial proportions in the images. The accuracy of the generated DEM was validated against 14 RTK-GPS check point observations collected biweekly on the beach, using terrestrial surveying based on a 5x5 meter grid. The accuracy of the DEMs generated with images taken at 35-, 45-, and 65-degree angles were respectively 0.53 feet, 0.61 feet and 0.73 feet. Index Terms—Coastal DEM Generation, Inundation, Oblique Imagery, SfM, Photogrammetry
DOI
10.5703/1288284317809
Generation of Coastal Area DEMs Using Oblique Stereo Imagery from Non-Metric Cameras with SfM Techniques
This study focuses on the the development of a method to create Digital Elevation Models (DEMs) for forecasting coastal inundation, a critical tool in the face of rising sea levels and extreme weather events. The study utilizes oblique stereo imagery captured with non-metric cameras, focusing on the area adjacent to Horace Caldwell pier in Port Aransas, Texas. The methodology involves the strategic placement of two Amcrest Ultra4K non-metric cameras on an elevated structure at the pier entrance. These cameras, positioned 8 meters above the ground and 20 meters apart, capture images at varying nadir angles high oblique (65 degrees), oblique (45 degrees), and less oblique (35 degrees). The project addresses the challenge of generating accurate DEMs from oblique stereo images, a task complicated by the fact that most existing software and techniques are designed for vertical imagery. Our method employs Structure from Motion (SfM) using stereo oblique images and non-metric cameras mounted on a coastal pier to create the DEMs. Key to the methodology is the careful calibration and application of advanced image processing techniques suited for high oblique imagery. Image processing-based methods use include wavelet transform for enhanced feature matching and clarity enhance ment, as well as rectification and georeferencing within MATLAB and ArcGIS Pro environments, respectively, to maintain true to-life spatial proportions in the images. The accuracy of the generated DEM was validated against 14 RTK-GPS check point observations collected biweekly on the beach, using terrestrial surveying based on a 5x5 meter grid. The accuracy of the DEMs generated with images taken at 35-, 45-, and 65-degree angles were respectively 0.53 feet, 0.61 feet and 0.73 feet. Index Terms—Coastal DEM Generation, Inundation, Oblique Imagery, SfM, Photogrammetry