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TREND SURFACE ANALYSIS APPLIED TO EVALUATION OF GEOLOGICAL AND 
GEOMORPHOLOGICAL INFLUENCES IN TM-LANDSAT DATA 
Albano Henrique de Araüjo 
Walter Riehl 
Osmar Abílio de Carvalho Jr. 
INFOSAT - Sensoriamento Remoto 
SQS, Od. 01, B. B 
Edificio Maristela, Sala 1214 
70000-000 - Brasilia - DF 
ISPRS Commision VII / Working Group 4 
ABSTRACT 
Trend surface analysis is a technique widely used in geology to decompose an original data set in 
regional and local components, indicating the goodness-of-fit between the original trend surface. The 
interpretation of trend surface of TM data allows the analysis of factors that determine the regional 
control in Landsat images. In this paper we compare the trend surface for TM bands (except 6) with 
geological and geomorphological information for two distinct areas. This procedure indicates if 
geological that geomorphological features are associated with regional trends of TM data. The results are 
quantitative and directs the use of a certain TM image to geological applications. To evaluate the method 
we select the Pirenópolis Mega-Inflection, a folded area, and the Ipameri region, two study areas with 
completely different topography and geology. The results indicate that TM-Landsat data in the 
Pirenópolis and Ipameri regions have regional trends that show good correlation with geological and 
geomorphological aspects and very low goodness-of-fit. This resul's confirm the hypothesis that the TM 
data are controlled by geomorphological and secondarily geological aspects. Moreover, the method 
quantifies indirectly the topography interference in each TM band indicating the adequate pairs in order 
to eliminate (by ratio) or enhance (by multiplication) the relief aspects. 
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