Selecting The Optimum Spectral Ratio for Detecting the Amount of Soil Cation and Anion by Using ASTER Satellite Photographs Case study: Dareh Anjir of Kavir-bafgh

Spectral ratioing or division of photos is probably considered as the most common arithmetic operations for enhancement of ground surface phenomenon by satellite images and has different usages in geological, ecological and agriculture and ecology. The main objective of this study is to evaluate various Spectral ratioing for separation of soil cations and anions and consequently selecting the optimum Spectral ratioing by using ASTER satellite photos in Bafgh, Dareh Anjir Kavir. To achieve this purpose, after applying geometric and radiometric correction and average filter, 56 various band ratios were produced.Then, 42 samples of soil were collected from ground surface 0-5 cm and the amount of their cations and anions was measured. The point map prepared from the profiles area were crossed with all informative layers obtained from spectral ratioing and the value of each profile reflectance was extracted. Cross validation method was used to measure the correlations and Root Mean Square Error between the estimated values of each band ratio and laboratory of each profile.The results showed that bands ratioing (b5/b6, b5/b8, b1/b2), (b11/b12, b6/9, b9/6) and b1/b2 can be used for enhancement of calcium, potassium and magnesium respectively b5/b6, b11/12 and (b7/b9 and b11/b10) can be used for enhancement of sulfate and bicarbonate respectively with the acceptable accuracy (R2>0.5, RMSE <13.61).