Using Fractal Filtering Technique for Processing ETM Data as Main Criteria for Evaluating of Gold Indices In North West of Iran

Alteration maps processed from the remotely sensed data may contain a large amount of information critical for mineral exploration. An alteration photomap is however not a type of "ready-to-use" data to determination of anomalies and the trends of enrichment required for predicting of mineral resources only if the different components of the digital numbers have been clearly divided. The fractal filtering technique, as recently-developed tool for decomposing different signatures, is able to separate the anomalous values from background and extract frequencies associate with mineralization processes as indirect digital indicators to altered sequences using concentration-area and spectrum-area models respectively. The fractal filter formed by applying the concentration model to the power spectrum of the processed images, often is a group irregularly shaped filters. Applying these types of filters in frequency domain can separate the following the same of similar power-law or fractal property. Being transformed to spatial domain, the corresponding patterns of the separated components can be obtained. In other word, the fractal filter can be applied to decompose the original remotely sensed data into a series of electromagnetic self-similar signatures with distinct scaling range and anisotropic peculiarities. The analysis to the relationships among these decomposed images can provide useful information for the evaluation of alterations and spatial distribution assessments around mineralized formations. This paper briefly introduces the theory of the fractal filtering technique; So it is going on with case study of most important gold-bearing anomaly in Sarigunny area, Kurdistan province, NW of Iran, will be used to illustrate application of this technique to process ETM images for regional determining of the epithermal alteration units within volcanic features as favorite targets of precious metals in the study area.