Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986 
Evaluation of digitally processed Landsat imagery and SIR-A 
imagery for geological analysis of West Java region, Indonesia 
Indroyono Soesilo & Richard A.Hoppin 
Department of Geology, University of Iowa, Iowa City, USA 
ABSTRACT : A regional geologic investigation of West Java area utilizing contrast-enhanced 
False Color Composite and Band-7 MSS Landsat imagery has resulted in the interpretation of 
regional geologic structure, the delineation of four physiographic zones and one volcanic chain 
in the area. 
The Band Ratio and the Principal Component Transformation were applied to Landsat data of 
the Sukabumi and Lembang areas to provide iirproved lithologic discrimination, while the Edge 
Enhancement technique applied to the same areas increased the capabilities for structural 
interpretation. A "multi-step interpretation" conducted to Landsat MSS data from this tropical 
region discriminated thirteen different lithologic terrains in the Sukabumi area and eleven 
different lithologic terrains from the Lembang area, while the Edge Enhanced imagery of these 
two sites provide additional understanding of the Cimandiri fault zone, the Lembang fault and 
the N - S maximum principal stress responsible for the development of structural patterns in 
this region. 
The SIR-A imagery of West Java area increased the topographic details lead to their 
structural geologic interpretations and used as additional information to the Landsat MSS data. 
INTRODUCTION 
The current impressive developments in remote sensing 
technology has been further advanced by major 
breaktroughs in aerial surveys and satellite 
technologies. Added to advances in computer 
technology which are providing enhanced imagery of 
remotely sensed data from satellite and airborne 
sensors, better analyses of earth surface phenomena 
are possible. 
The development of the radar remote sensing system, 
with its capabilities as a day or night, all weather, 
"vegetation penetration"- active imaging system, has 
made the survey of tropical regions more accessible. 
The radar sensing system has evolved recently from a 
more constrained Side Looking Airborne Radar system 
(SLAR) into the Synthetic Aperture Radar system (SAR) 
and from an airborne plaform into Satellite and Space 
Shuttle platform (Seasat SAR and Shuttle Imaging 
Radar). 
Geological investigation of tropical areas, such as 
found in Indonesia, using remote sensing technology 
often has to cope with environmental variables such as 
dense vegetation canopy, the high rate of weathering, 
weather and climatic factors. The capabilities of this 
technology to assist in solving geological problems in 
this tropical region has recently been accessed in 
conjuction with the Natural Resources Inventory 
program currently being conducted by the Indonesian 
government (Asmoro, 1978). 
This paper is especially directed toward determining 
the capabilities of Landsat and its digitally 
processed imagery and of SIR-A imagery for lithologic 
and structural geologic investigations in this 
tropical environment. Attention is focused 
particularly of determining the methods on pattern 
recognition through interpretation of tone, texture 
and shape of the surface. 
A section of West Java was chosen as the test area 
for this investigation. The digital image processing 
and analysis were concentrated in two test sites 
within the investigated area, the Sukabumi and Lembang 
areas - where a ground investigation was also 
conducted (Figure:1 ). This location was selected 
because all of West Java's physiographic zones 
(Bemmelen, 1949) are represented in this area and each 
of these zones exhibits a typical lithologic character 
which can be discernable on various digitally 
processed Landsat imagery. This region is also 
tectonically active and is a p>art of the western 
Indonesia island arc system. The structural analysis 
of this region will provide an important tectonic 
synthesis for identification of seismic hazards and 
for exploration of economic minerals. 
Figure 1: Index map of Landsat 5 and SIR-A coverage, 
West Java - Indonesia. Also shown the two test sites, 
Sukabumi area (SW) and Lenbang area (NE).