Digital Mono-Plotting Within a GIS Application in Forestry

Josh A. Goncalves

Abstract:	Geographic Information Systems (GIS) are popular in natural resources management, especially in forestry. One of the main data sources is aerial photography but most GIS packages can’t deal with the exact geometry of image formation. In mountainous terrain the geometric distortions due to relief displacement are very large and cannot be modelled by projective or polynomial transformations, present in those software packages. Photogrammetric techniques (analytical or digital) are time and money consuming. The approach proposed here is to do an image integration of a scanned aerial photograph in the GIS, orient it by space resection, digitise lines in photo-coordinates and rectify them with a Digital Elevation Model (DEM). This is what is called a Digital Mono Plotting System, and avoids the creation of ortho-images. This problem was studied within Arc/Info making use of tools for image integration, image registration, line digitising and terrain modelling. This model is now being applied to recent false colour aerial photography (approx. scale 1: 18,000) available in Portugnl for forestry applications. Important problems to be addressed relate to DEM availability and accuracy, measurement of ground control points (GCP) coordinates and the global accuracy of the final product. The first tests carried out with DEM’s created from 10 m contours and GCP coordinates obtained from 1:25,000 maps, as well as with GPS code receivers, gave acceptable accuracy for forestry applications.
Published in:	Proceedings of the 50th Annual Meeting of The Institute of Navigation (1994) June 6 - 8, 1994 Antlers Doubletree Hotel Colorado Springs, CO
Pages:	189 - 195
Cite this article:	Goncalves, Josh A., "Digital Mono-Plotting Within a GIS Application in Forestry," Proceedings of the 50th Annual Meeting of The Institute of Navigation (1994), Colorado Springs, CO, June 1994, pp. 189-195.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In