Digital Surface Modelling in Developing Countries Using Spaceborne SAR Techniques

Edwards, Earl Peter Fitz-Gerald (2005) Digital Surface Modelling in Developing Countries Using Spaceborne SAR Techniques. PhD thesis, University of Nottingham.

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Abstract

Topographic databases at the national level, in the form of Digital Surface Models (DSMs), are required for a large number of applications which have been spurred on by the increased use of Geographic Information Systems (GIS). Ground-Based (surveying, GPS, etc.) and traditional airborne approaches to generating topographic information are proving to be time consuming and costly for applications in developing countries. Where these countries are located in the tropical zone, they are affected by the additional problem of cloud cover which could cause delays for almost 75% of the year in obtaining optical imagery. The Caribbean happens to be one such affected territory that is in need of national digital topographic information for its GIS database developments, 3D visualization of landscapes and for use in the digital ortho-rectification of satellite imagery.

The use of Synthetic Aperture Radar (SAR), with its cloud penetrating and day/night imaging capabilities, is emerging as a possible remote sensing tool for use in cloud affected territories. There has been success with airborne single-pass dual antennae systems (e.g. STAR 3i) and the Shuttle Radar Topographic Mapping (SRTM) mission. However, the use of these systems in the Caribbean are restrictive and datasets will not be generally available. The launching of imaging radar satellites such as ERS-1, ERS-2, Radarsat-1 and more recently Envisat have provided additional opportunities for augmenting the technologies available for generating medium accuracy, low cost, topographic information for developing countries by using the techniques of Radargrammetry (StereoSAR) and Interferometric SAR (InSAR).

The primary aim of this research was to develop, from scratch, a prototype StereoSAR system based on automatic stereo matching and space intersection algorithms to generate medium accuracy, low cost DSMs, using various influencing parameters without any recourse to ground control points. The result was to be a software package to undertake this process for implementation on a personal computer. The DSMs generated from Radarsat-1 and Envisat SAR imagery were compared with a reference surface from airborne InSAR and conclusions with respect to the quality of the StereoSAR DSMs are presented. Work required to further improve the StereoSAR system is also suggested.

Item Type:Thesis (PhD)
Supervisors:Sowter, Andrew
Smith, Martin John
Uncontrolled Keywords:DEM, Digital Elevation Modelling, Digital Surface Modelling, SAR, Space Intersection, Stereo Matching, Automatic DEM Extraction, StereoSAR, Radargrammetry, Topographic Information, Topographic Databases, DEM Algorithms
Faculties/Schools:UK Campuses > Faculty of Engineering > School of Civil Engineering
ID Code:157
Deposited By:Earl Peter Fitz-Gerald Edwards
Deposited On:07 Feb 2006
Last Modified:06 Feb 2009 14:43

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