NGINEER (GIS 
MANAGEMEN 
ITUTE, LAHON 
Munro, Duncan 
COMPARATIVE ANALYSIS OF LANDSAT-5 AND LANDSAT-7 DATA FOR LAND COVER 
CLASSIFICATION, QUALITATIVE EVALUATION OF IMAGE FUSION PRODUCTS AND 
INVESTIGATION OF THERMAL CHARACTERISTICS OF INDUSTRIAL DISCHARGE SOURCES 
Andrea PATRONO, Duncan MUNRO 
Western European Union Satellite Centre, Madrid, Spain 
pat weusc.es, mun  weusc.es 
KEY WORDS: Multi-sensor, Classification, Data fusion, Land use/Land cover, Geology, Industry. 
ABSTRACT 
The Western European Union Satellite Centre (WEUSC) recently commenced participation in the evaluation of the con- 
tinuity of data from the LANDSAT programme. À study area has been selected in the province of Extremadura, Western 
Spain, which comprises a variety of land cover categories and geological formations. In addition the Almaraz power gen- 
erating facilities were included in the study area. Using image acquisition from LANDSAT-5 and 7 and near simultane- 
ous acquisition of SPOT panchromatic images for several dates, a series of comparisons designed to evaluate qualitative 
and quantitative aspects of the two multi-spectral data sets is undertaken. Image fusion products utilising panchromatic 
data with a smaller pixel size (SPOT panchromatic 10 m pixels and LANDSAT-7 Band 8 15 m pixels) and multi-spectral 
data (LANDSAT-5 Thematic Mapper (TM) and LANDSAT-7 Enhanced Thematic Mapper Plus (ETM+)) with coarser 
pixels are investigated to evaluate their use as image interpretation products. The consistency between results made using 
supervised classification approach to LANDSAT-5 and LANDSAT-7 are presented. Comparison with existing geological 
and land cover maps is made to assess the results of the image classification/interpretation. The utility of the thermal 
infrared band of the TM and ETM+ - with special attention to the improvements implemented on the last one - is investi- 
gated using as objective the temperature in the reservoir immediately adjacent to the Almaraz power generating facility. 
1 INTRODUCTION 
1.1 Study Objectives 
The main objectives of this study were a comparative analysis of LANDSAT-5 and LANDSAT-7 for land cover classifi- 
cation and image fusion products and monitoring of industrial sources using thermal infrared data in the area of the 
Almaraz power plant, Extremadura, Spain. The following goals were considered: (1) Study of the area surrounding the 
power plant with emphasis on the land cover and the structural-geology. The simultaneous acquisition by the ETM+ of 
the pan and multi-spectral channels was expected to improve (considering the characteristics of the TM on LANDSAT-5) 
the interpretation and understanding of the land cover and geological settings of the area. (2) Analysis of power plant 
activity with particular emphasis on the possible exploitation of the redesigned thermal band provided by the ETM+. The 
improved spatial resolution (from 120 to 60 m) was designed to provide significant benefits to the analysis of surface 
processes and thermal activities (e.g. power generating plants). (3) Comparison of image fusion and classification tech- 
niques developed to achieve goals (1)-(2) using two sets of images: LANDSAT-7 (multi-spectral plus panchromatic 
band) and LANDSAT-5 plus SPOT PAN. The aim of this comparison was to estimate the difference between the results 
obtained in the two cases, i.e. one representing the new RS market state and the other a comparable situation before the 
launch of LANDSAT-7. . 
For goals 1 and 2, feature analysis and extraction played a fundamental role in the interpretation processes required to 
achieve the proposed goals. The resolution and (multi-)spectral information are key factors in remotely sensed images 
interpretation. The contribution of fused products (e.g. a higher resolution panchromatic image merged with a lower res- 
olution multi-spectral image) in broadening the discriminative capabilities may be summarized as follows: spatial char- 
acteristics of objects such as shape and texture are usually better highlighted in panchromatic images whilst spectral 
characteristics can often be characterized by behaviour in the near-infrared region of the spectrum. The fused products 
maintain the characteristics of the higher resolution panchromatic scene, thus offering a better match with larger scale 
georeferenced information. The simultaneous acquisition of panchromatic and multi-spectral data by LANDSAT-7 
reduces greatly the geometric processing required to perform resolution merges within a single scene. Before its launch 
TM products had to be merged with higher resolution panchromatic products acquired by other sensors. For these rea- 
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 931