Teacher

prof. aggr. Alberto BEINAT

Credits

6 CFU

Objectives

The course aims to:
- present the technologies for the extensive survey of the territory, and the tools for the collection and analysis of georeferenced environmental variables;
- experiment the use of computer tools for the digital modeling of the territory and for the analysis of remote sensing data of the environment;
- know and experience the spatial analysis tools offered by the Geographic Information Systems

Acquired skills

- know the coordinate and reference systems used in surveying and mapping
- develop tools for the rigorous coordinate conversion and transformation
- know the characteristics of the digital terrain models
- develop tools for the creation, management, and analysis of digital terrain models
- know the basics and the potential of remote sensing for the acquisition of land and environmental data
- develop tools to perform basic elaborations on remote sensing data
- know the functionalities of the geographic information systems (GIS)
- acquire notions about data structures and database architecture.
- perform basic operations on georeferenced data through open-source programs.

Contents

Digital terrain models Definition and types. DSM, DTM and DEM. Vector and grid structures. Classification and production techniques of DEMs. Interpolation, formats and metrical qualities. 6h
Reference frames in surveying and mapping Reference system (datum) definition. Geocentric cartesian systems. Geographic ellipsoidal systems. Projected Cartesian systems. Conversions between reference systems. Main reference systems adopted in Italy. 2h
Coordinate conversion and transformation General conceptual framework for the transformation between reference systems. Helmert’s cartesian geocentric transformation. Direct estimation of the 7 parameters using Singular Value Decomposition. Transformation of Molodenskij. Transformation grids: IGM and NvT2 formats. Local affine transformation. Dynamic reference systems for GNSS. Realizations. Networks and agencies. WGS84 and ETRS-ITRS systems. Realizations ITRFxx, IGSxx, ETRFxx. The kinematic model. 2h
The physical basis of remote sensing Main components of the technology. The physical basis of remote sensing. Energy of an electromagnetic wave. Spectrum. Subdivision of the spectrum as a function of the wavelength. Fundamental laws of physics: energy of a photon, Stefan-Boltzmann law, Wien's Law. Interactions between atmosphere and electromagnetic waves: dispersion, diffusion, absorption and transmission. Interactions between energy and the Earth's surface. Spectral signature. 4h
Platforms and sensors for remote sensing Platforms and sensors. Traditional photogrammetric camera systems. Film composition and characteristics. Multispectral systems. The Landsat system and the TM - ThematicMapper sensor. The SPOT system and the HRVIR sensor. The AVHRR and MODIS sensors, Ikonos, QuickBird, Eros, GeoEye, Envisat and EOS systems. Hyperspectral systems: AVIRIS, MIVIS, AIS etc.. 4h
Principles of Remote Sensing data processing The hyper image concept: object space and image space. Processing phases of remotely sensed images. Georeferencing. Resampling. Absolute and relative radiometric correction. Atmospheric correction. Topographic correction. Improvement of images by digital filters. Low-pass filters, high pass filters, etc.. Image space and multispectral transformations. DN - Digital Number. Map-algebra operations. Calculation of indices: "Vegetation index", NDVI - "Normalised Difference Vegetation Index," NBR - "Burn normalized ratio" etc.. Image segmentation and object extraction. Bands, band correlation, variance-covariance matrix. PCA - "Principal Component Analysis". TCT - "Tasselled Cap Transformation." Interpretation of remotely sensed images. Segmentation (dichotomous threshold, interval, "region growing"). Classification (multidimensional threshold, minimum distance ...). Clustering (K-means, ISODATA). 8h
Geographic Information Systems (GIS) Definition, history, characteristics, main functions. 2 Conceptual and physical models Models, structures, and formats of GIS. Conceptual, logical, and physical models. Examples. 2h
Data structures Vector and raster data structures. DEM data structures. TIN models and Delone triangulation. 2h
GIS functions and processing Main functions of GIS software. Format conversion (topological, map, and GIS-oriented). Error Correction. Vector-raster conversion. Crop. Mosaicking. Spatial analysis functions. Selection, aggregation and reclassification. Overlay. Boolean operations. Buffering. Network analysis. Map algebra. DEM based computations: slope, aspect, drainage network ... etc.. Tutorial: GIS processing. Creating DTM from digital mapping. Coordinate transformation. Interpolation and resampling on regular grid. Database queries. Buffering functions. Raster and vector data layers overlay. Map algebra functions. 8h

References

Technical documentation and manuals provided by the teacher.
Additional material or information available at http://https://materialedidattico.uniud.it/

The laboratory activities are based on the GIS software "QuantumGIS" (license free), and on a numerical computing environment like Matlab (license proprietary) or similar (eg, Octave, Scilab – license free).

Type of exam

Oral test, and presentation of a report on the laboratory activities carried out during the course