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Title REVISION OF 1:50,000 TOPOGRAPHIC SHEET USING SATELLITE IMAGERY PRELIMINARY STUDIES
Full text http://dspace.knust.edu.gh/dspace/handle/123456789/791
Date 1997
Author(s) Duker, A.A.; Okrah, E.A.
Abstract Topographic map coverage of Ghana is a costly project, considering both acquisition of the aerial photographs and the mapping that covers the entire country. It has therefore often gone as a bilateral project. It becomes therefore imperative, considering the rate of development in the country, to revise these ageing maps consistently rather than allow them to get out-dated and unattended to. Though revision by aerial photographs would have been the best method by reason of their resolution, reflying large areas for revision would be a costly project. Reflying to obtain new aerial photographs for revision is also costly. Considering the fact that revision must often be selective, the use of satellite imagery may be a good alternative and must be exploited. The study limits itself in this stage to the Landsat TM with a pixel size of 30m and the SPOT XS also with a pixel size of 20m. In this paper, a level 1B SPOT XS imagery at 20 m pixel and a Landsat Thematic Mapper of pixel size of 30m are rectified to a Transverse Mercator Projection using control points (Map coordinates) and a digitizer with a resolution of 0.03mm. Performance of the imagery with regard to accuracy (geometric fidelity) feature identification and the economic implications are discussed. Alternative proposals are also outlined.
Publisher KNUST
Identifier 0855-0395
Repository Kumasi - Kwame Nkrumah University
Added to C-A: 2010-02-23;08:57:24