ENGE414
Digital Terrain Model
Syllabus
- Introduction (3 hours)
- Definition and importance of digital terrain model (DTM)
- Historical development of terrain modeling
- Stages of terrain model generation
- Types of terrain models (DTM, DEM, DSM, CHM, nDSM, REM)
- Applications of DTM
- Challenges and opportunities in the field of terrain modeling
- Terrain Descriptors and Sampling Strategies (6 hours)
- General terrain descriptor
- Numerical terrain descriptor: Frequency spectrum; Fractal dimension; Curvature; Covariance and auto correlation; Semi variogram
- Sampling techniques: Types of sampling (Random, stratified, systematic, clustering); Selective Sampling; Sampling with one dimension fixed; Sampling with two dimensions fixed; Composite sampling (An integrate strategy)
- Data Acquisition for DTM (7 hours)
- Cartographic source: Scanning maps; Removing noise; Contour detection, binarization and skeletonization; Contour following
- Photogrammetric data source: Analog and digital photogrammetry
- Satellite techniques: Radargrammetry, SAR interferometry and satellite setreogrammetry
- Light detection and ranging (LiDAR): Spaceborne and airborne LiDAR
- Global navigation satellite system (GNSS): Principles of GNSS measurement and its operation
- Comparisons between DTM Data from different sources
- DTM Data Structures (6 hours)
- Data structure contour, grid and TIN
- Storage and compression techniques of grid data: Cell-by-Cell storage; Run-length code; Quad tree
- Creating TINs from grid and irregularly distributed data
- Voronoi diagrams and Delaunay triangulation
- Digital Terrain Modelling Manipulation (6 hours)
- Surface classification: Functional versus solid, continuous versus non-continuous and smooth versus non-smoothed surfaces
- Global and local interpolations methods: Inverse distance weighting (IDW), kriging and spline interpolations
- Comparison of interpolation methods
- DTM Derivatives and Volume Computations (6 hours)
- DTM derivatives: Slope, aspect, curvature, view sheds and watershed
- Volume computations from contour and grid data
- Generating contour lines from grid data
- Applications of DTM (7 hours)
- Orthoimage of generation
- Telecommunications
- Flood prediction, data fusion
- 3D models and visualization
- Renewable energy site assessment (Wind and solar farms)
- DTM Quality Assessment (4 hours)
- Sources and types of errors in DTM
- Techniques for error assessment: Filtering of random errors of the original data; Gross errors in grid data; Isolated gross error in irregularly distributed data; Cluster gross error in irregularly distributed data; Gross error in topologic relations of contours
- Quality control: Concepts and strategy
- DTM accuracy assessments: Approaches for DTM accuracy assessments; Distributions of DTM errors; Factor affecting DTM accuracy; Strategies for experimental tests; Requirements for checkpoints in experimental tests
Practicals
- DTM capturing
- Automation and manual terrain extraction
- Comparisons of different interpolation methods
- Generation of DTM derivatives
- Application: Case study analysis (Applying DTM in urban planning); Identifying potential natural hazards using terrain models
- Accuracy assessments: Assessing the accuracy of a DTM; Implementing quality control procedures in DTM projects