Dear Gamal,

Both these methods are applicable depending on concrete geological-geophysical pattern.

Lev

Dear Lev,

Thank you very much for the reply. I agree with you.  It depends.

Gamal

Dear Gamal,

In the interpretation of aerial photographs is a distinction between "pre-controlled" and "not previously controlled" airial images interpretation. "Previously controlled" means that an experienced field geologist has directly quantified the pattern of lineaments (faults, fractures, foliation, etc.) in the field.

This "pre-controlled" method can not be replaced by "not previously controlled interpretation".

HOWEVER, the "not previously controlled" aerial photo interpretation has significant advantages in extremely large areas. The geologist must not laboriously struggling through the field.

Best regards,

Guenter

I follow the Richard Gloaguen, Lineaments control the variety of mineral deposits, different geological formations. I hope, that instead of automatic extraction, manual mapping is good. In GIS environment, we can perform very good lineament map, mean time ground truth verification is important.

Manual map in GIS environment using satellite images with ground truth verification

I think Richard Gloaguen have a long experience in lineament mapping and I read some of his articles and conference abstracts. Generally, lineament mapping is conducted the prior to field work to get a general idea about the study area if have never been visited, and to prepare base map that will be checked during the field work. From my point of view, I believe that manual extraction is better, though it is time consuming, because you have the choice to draw the lineament that are more important to you study. Indeed, not all lineament are of equal importance.

Dear Khalid:

Thank you very much for the reply & feedback. I agree, manual extraction of lineaments gives more reliable information than the automatic extraction. Nevertheless, automatic extraction can be used to give some sort of initial approximation for lineament candidates, which can be promoted to a more reliable ones by manual interpretation. In a way, we need to combine both extraction methods to come up with an optimal strategy for lineaments extraction. Although the work on lineaments is a classical topic in geology and other fields, the new flood of data that we are getting from the new and different sensors is calling for more authenticated automatic methods and systems for lineaments extraction and interpretation or labeling. For example, hyper-spectral sensors are delivering 200+ bands/area, which cannot be exploited in-depth by manual techniques. In general, some kind of expert systems of hybrid-nature need to be developed to address the lineaments extraction and others.

Regards,

Gamal

In my view manual gives better results as most of the surface expressions of faults are not so wide to be identified by a 30 m or even 10 m resolution image; if you have a very high resolution image e.g. 1 m or so then automatic gives good results otherwise they don't identify faults but only streams and ridges.