Extraction of linear and anomalous features using ERS SAR data over Singhbhum Shear Zone, Jharkhand using fast Fourier transform

Abstract

Digital filtering of ERS‐2 SAR data using the fast Fourier transform (FFT) has been attempted over Singhbhum shear zone (SSZ) and its surroundings for extraction of linear and anomalous patterns. The results show that numerous lineaments as well as drainage patterns could be identified and demarcated by FFT digital filtering method. Major as well as several minor drainage patterns are easily detectable from the filtered image, which are structurally controlled and not observed in the original map. Comparison of the present interpretation of the study area to existing geological map/earlier interpretation has been done effectively. This technique was found to be more effective in identifying the lineaments using ERS SAR data compared with using Landsat imagery over the study area. The present study reveals that maximum lineaments occurring in the north of SSZ are NNE, NNW and NW trending, while maximum lineaments occurring in the south of SSZ are NE, ENE, WNW, and NW trending. The demarcated geological structures may have a great significance to locate the hidden ore/mineral occurrences. The existences of various mines, such as Baharagora, Mosaboni, Surda, Narwa, Bhatin, Jadugoda, Rakha, and Tatanagar along the shear zone, correlate well with the interpreted results.

Acknowledgements

The authors wish to thank the anonymous referees for their critical comments and suggestions for the improvement of the manuscript. They are also thankful to Dr R. R. Navalgund, Director, SAC, Dr K. L. Majumder, Deputy Director, RESIPA/SAC and Dr S. R. Nayak, Group Director, MWRG/RESIPA for their keen interest in this study. Thanks are due to Shri R. Bhattacharyya and Shri S. Chatterjee, ESHD for their help at various stages of this activity.