Mularz, Stanislaw 
  
MERGING LANDSAT TM IMAGES AND AIRBORNE PHOTOGRAPHS FOR MONITORING OF 
OPEN-CAST MINE AREA 
Stanislaw MULARZ, Wojciech DRZEWIECKI, Tomasz PIROWSKI 
University of Mining and Metallurgy, Krakow, Poland 
Department of Photogrammetry and Remote Sensing Informatics 
mularz@uci.agh.edu.pl 
KEY WORDS: Data Fusion, Multi-sensor, Remote Sensing, Image Processing, Integration, Geology, Open-cast mine 
ABSTRACT 
Merging Landsat TM mutispectral image and airborne photography is the general concept of the study presented. The 
large Lignite Open-Cast Mine „Belchatow” located in the central part of Poland, was a study area. The main subject of 
this investigation was used merged satellite and aerial images for discrimination of the geological features and detection 
of the mining structure and geometry of the open pit mine. Visual and statistical analysis methods were used to 
determine the amount and distribution of information contained in the data sets. The Optimum Index Factor (OIF) was 
used to rank the three band combination. Using both, visual and OIF methods, the seven of three-band Landsat pairs 
were selected for merging procedure. A number of merging methods have been tested: IHS, HPF, PCA, SC, CN, 
Cliché's and Jaakkola's. Three band color composite images corroborated the statistical results. The best result was 
obtained using IHS and HPF (31x31) methods and the following Landsat combination: TM(431), (754), (742), (543) 
displayed as RGB. The maximum values of OIF had Landsat TM (451,543,531) combinations, which indicate a good 
agreement between visually and statistically assessment of interpretability. The factors that enable TM visible and 
infrared bands to discriminate the geological features are connected with spectral signatures of the lithological units. In 
particular, the carbonate, silicate, sulfate and clay mineralogies of the sedimentary rock units were responsible for the 
specific spectral properties. Merging the satellite and aerial images seems to be a good way for enhancement the 
interpretability of the Landsat TM data. 
1 INTRODUCTION 
In many applications of remote sensing a high spatial resolution is required. This is especially important when satellite 
multispectral imageries, of relatively poor spatial resolution, are using. High spatial resolution is necessary for the 
detection of the particular objects as well as more accurate description of shapes, features and structures. For many 
applications the benefit of obtaining highest spatial resolution is evident, particularly for land-use / land cover 
classification, urban studies, farming inventory and environmental monitoring problems. On the other hand, depending 
on the type of application and the level of landscape complexity the detection and recognition of relatively small objects 
is possible, if high spectral resolution images are used. Hence, there is a desire to merge both high multispectral 
imageries and high spatial resolution images. Using such concept one can obtain most complete and accurate resulting 
images an area of interest. Merging the data collected by the two different satellite systems it is possible to get a 
complementary information provided by each of the two sensors. Examples of such a data set are the Landsat TM has 
six multispectral bands (30 m) and the SPOT PAN panchromatic mode (10 m) images. The main concept of sensor 
fusion is to preserve the multispectral content of images at a low spatial resolution (like Landsat TM or SPOT XS) and 
images at a higher spatial resolution but with a poor spectral content (like SPOT PAN). However, not all of the existing 
merging methods fulfil this idea: This paper discusses currently most used methods and their advantages and 
disadvantages connecting with the monitoring problems of an open-cast areas. For such specific and relatively small 
areas satellite multispectral sensors have to be merged with now available images at much higher spatial resolution. 
Many of authors have been reported of successfully using pixel-by-pixel and other more complex mathematic 
procedures to merge Landsat spectral bands with digitised aerial photographs (Chavez, 1986; Cliche et al., 1985; 
Chavez et al., 1982, 1984; Ranchin and Wald, 2000). 
For geologic remote sensing an attempt to merge satellite multispectral Landsat MSS and TM images together with the 
digital aerial photographs have been also successfully done by Dennis N. Grasso (1993). 
In the study presented the Landsat TM (30 m) and airborne photography (2 m) have been used for merging, with the 
aim of improving the spatial resolution together with a good preservation of the spectral content of integrated images. 
  
920 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 
  
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