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- 2163 - 
SPECTRAL SIGNATURES OF GEOLOGICAL LINEATIONS ON LANDSAT 
IMAGERY 
Anne-Marie Martin 
Lecturer - Photointerpretation for Geologists, Geologisches 
Institut/Geotechnik, Ruhr Universitat Bochum 
Introduction 
"The word "signature," by definition, refers in general to a 
distinguishing characteristic. In remote sensing, a "spectral 
signature" of a feature comprises a set of values for the. re- 
flectance or the radiance of the feature, where each value 
corresponds to the reflectance or radiance averaged over a dif- 
ferent, well defined, wave-length interval." (Manual of Remote 
Sensing, p. 258) However, this criterion is redefined further 
as "quantitative measurement of the properties of an object at 
one or several wave-length intervals." (Manual of Remote Sen- 
sing, p. 2104) 
Due to the confusion occasioned by the above illustrated differ- 
ences in terminology, for the purposes of this presentation a 
"spectral signature" will be considered as a photo-lineation 
appreciable on LANDSAT imagery, and presumably relating to 
geology. (HOPPE 1974) 
Definition 
The terms "linear" and "lineament" have been used in photointer- 
pretation of aerial photographs and may be defined as: 
linear lines of uncertain origin which are determined on 
air photographs and/or other imagery 
lineament linear features known on the ground; by extension 
those discovered in the course of field-work. 
(ISACHSEN et al. 1972) 
In the broadest sense a "photo-lineation" may be considered as 
any extent of linears appearing on imagery, and may therefore 
relate to features other than geology. Therefore, a composite 
term is used here - "geological lineations" - indicating that 
the discussed features are not lines of vegetation, highways, 
valleys or strcam beds, etc. The linears which have been mapped 
from LANDSAT imagery are considered to represent geological linea- 
ments. 
Geological Formations 
In Geology, linears distinguished on aerial photographs are 
relatively simple to define and represent often tectonic linea- 
ments, lithological boundaries, faults and fracture zones. This 
fact has often been used to locate ores, ground water reserves, 
building and road materials, etc. Remote sensing has provided 
a broader view of known areas and permits surveying and mapping 
of previously unknown formations, even in an area as well field- 
checked as the Federal Republic of Germany. (ADLER 1978; GÜNTHER 
1978; HOPPE 1974; KRONBERG 1974; REUL 1975, 1974; REEVES et al. 
1975; STREIT 1977)