Alavipanah, Seyedkazem 
  
The PCA transformation model for the three most informative components can be 
written as following: 
PC1= 0.487 TM2 + 0.480 TM3 + 0.503 TM4 + 0.265 TMS - 0.381 TM6 + 0.252 TM7 
PC2- -0.185 TM2 - 0.225 TM3 - 0.013 TM4 + 0.632 TMS + 0.328 TM6 + 0.640 TM7 
PC3- 0.284 TM2 + 0.268 TM3 + 0.258 TM4 + 0.117 TM5 + 0.864 TM6 - ).145 TM7 
Two dimensional FS analysis of the Ardakan area shows that the dark color salt 
crust can be separated by TM6. It means they have a large temperature rise of the dark 
crust class may be due its location in a depression. This depression may capture more 
radiation and retaining more temperature. In other words, the layout of buildings and 
pavement within an urban landscape can also affect the appearance of the urban heat 
island ( Goward, 1981 ). Nichol ( 1994 ) has successfully utilized Landsat TM thermal 
infrared data to derive surface temperature data for some housing estates in Singapore. 
Conclusion : 
The TM satellite images is offering a valuable contribution to fulfilling the 
information need in detecting salt crust from the other crusted surface. Based on the 
obtained results we may generally conclude that TM visible bonds and TM infrared 
bands may have some valuable information on salt crust that are usually 
complementary to each other. we also may conclude that TM thermal band can be 
effectively used for separating urban and salt crust with dark to brownish color. We 
may also conclude that a better understanding of some characteristics of crusted 
surface developed in desert areas are necessary to improve image interpretation . 
References : 
1- Alavi panah, S.K. and R. Goossens, 1999. The role of TM thermal band in 
describing the state/stress of vegetation in the Iranian Deserts. Proceedings of RS in 
the 21 century: Economic and Environmental applications. 19 the EARSel Symposium, 
University of vallodolid, Spain, 31 May-2June, 1999, 31-37. 
2- Goossens, R. and E. Van Ranst, 1996. The use of RS and GIS to detect gypsiferous 
soils in the Ismailia province ( Egypt ), proceedings of the International Symposium on 
Soil with Gypsum. Lieida, 15-21 September, 1996. Catalonia, Spain. 
3- Goudharzi, G.H. 1970, Non-metalic mineral resources : Saline deposits, Silica sand, 
sulfur and trona. USGS professional paper- 660. 
4- Goward, S.N., 1981. Thermal behavior of urban landscapes and the urban heat 
island. physical geography, 2: 19-33. 
  
44 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. .