Symposium on Remote Sensing for Dn ^^nrces Development and Environmental Management / Enschede / August 1986 
569 
Comparison between interpretations of images of different nature 
G.Bollettinari 
Morfogeo s.a.s., Ferrara, Italy 
F. Mantovani 
Ferrara University, Italy 
ABSTRACT: Data obtained analaizing images of different nature, are described to interprete from the neotectonic 
point of view some geomorphological feactures of the central and northern area of Perù. The purpose of this pa 
per is the research of the relations ship between photointerpretation, obtained data and their reliability. 
Particularly merits and shortages,interpretative limits, and the fitness use of each type of images for the over 
mentioned work, will be described. 
RIASSUNTO: Vengono descritti i dati ottenuti analizzando e confrontando immagini di differente natura, con lo 
scopo di interpretare in chiave neotettonica le caratteristiche geomorfologiche dell'area centro settentrionale 
del Perù. Scopo della presente nota è la ricerca dei rapporti intercorrenti fra fotointerpretazione, dati rica 
vati e loro attendibilità. In particolare vengono sottolineati i pregi e le carenze riscontrati, per ciascuna 
immagine, al fine di tracciare i limiti del dettaglio interpretativo e la destinazione d'uso più idonea. 
1 INTRODUCTION 
The following note is in reference to the preliminary, 
photointerpretative phase of a multi-faceted study 
aimed at identifying the principle neotectonic featu 
res of a high plain area in the Peruvian Andes. 
In particular is here analyzed a photointerpreta 
tion process applied to different types of images and 
the morphoneotectonics classification also used. At 
the end, the various advantages and disadvantages of 
each type of image is underlined, indicating any limi 
tation in interpretative detail and, based on the re 
sults, the use to which it is most suited. 
2 PHOTOINTERPRETATION PROCESS 
The area studied is in the Peruvian Andes N 10° Lat 
S within a 100-Km-wide area extending approximately 
400 Km NNW-SSE and including the Andean high plain. 
The following documents were used: 
a- LANDSAT images, average scale 1:250,000, spectral 
band 7; 
b- LANDSAT F.C.C. (false colour composite) images 
obtained by automatic procedure of spectral bands 4, 
5 and 7, average scale 1:250,000; 
c- SLAR black and white photomosaic images, average 
scale 1:100,000; 
d- Panchromatic black and white photomosaic aerial 
photographs, average scale 1:100,000. 
The procedure followed two successive phases of the 
photographic documents available. The first phase 
consisted of a field assessment of those photoalignm 
ents of certain natural origin to which a tectonic 
meaning could be attributed; that is association with 
faults or fractures. The second phase consisted of a 
classification of the natural, tectonically signifi 
cant photoalignments in the above-mentioned field: 
those which were not fully developed were eliminated 
unless fully aligned or associated with other alignm 
ents . 
2.1 Phase 1. Assessment and distribution of total 
field 
For assessment and distribution of the tectonically 
significant natural photoalignments of the total field 
the procedure was as follows: 
a- Interpretation of the black and white LANDSAT 
images; 
b- Interpretation of the F.C.C. LANDSAT images; 
c- Interpretation of the SLAR images; 
d- Interpretation of the panchromatic black and 
white photomosaic. 
In particular the basically straight alignments as 
well as circular areas were separately identified for 
each type of image from their photographic and/or 
morphological expressions. The former were seen as 
variations in tone, texture, structure, contrast, 
glossiness, etc. of the object. The latter define va 
rious alignment patterns: lithological (contact bet 
ween different lithotypes), structural (dip and stri 
ke, faults, fractures, etc.), hydrographic and orogra 
phic (water courses, valleys, watersheds, escarpments, 
etc.). 
2.2 Phase 2. Classification of photoalignments from 
the total field 
After assessment of the photoalignments had been com 
pleted they were classified on the following basis: 
a- continuous photoalignment planimetry; 
b- correspondence of the photoalignments in the dif 
ferent images used.