Multispectral aerial photography as exploration tool IV–V: An application in the Khomas trough region, South West Africa; and cost effectiveness analysis and conclusions

• Published in: Remote sensing of environment 1976, Vol.5 (2), p.93-107
• Main Authors: Gilbertson, B., Longshaw, T.G., Viljoen, R.P.
• Format: Article
• Language: English
• ISSN: 0034-4257; 1879-0704
• DOI: 10.1016/0034-4257(76)90041-9

This paper is the fourth and last in a series devoted to the evaluation of “text-book” multispectral aerial photography (TMSAP) as exploration tool. The first part of the paper describes a survey that attempted to identify gossaniferous outcrops which are the surface expression of certain massive sulphide bodies. Conventional colour (Kodak 2448) and false colour infrared (Kodak 2443) photography was acquired for comparative purposes. It was found that of these photographic techniques, the multispectral gave the best discrimination between the gossaniferous outcrop and the background rock types. The second part of the paper presents our overall conclusions regarding the effectiveness of TMSAP in exploration applications. It is noted that although TMSAP enhances spectral differences between object categories, these differences can generally also be detected on conventional photography. Out of the total of 55 pairwise discriminations between object categories that were sought in the course of our 4 experiments, TMSAP performed significantly better than conventional photography in only 7 cases. This slight superiority of TMSAP is outweighed by important theoretical, practical and economic limitations. It is demonstrated that the cost of a TMSAP survey can be typically an order of magnitude greater than the cost of a conventional photographic survey. These factors preclude TMSAP as an effective exploration tool.