Item

Abstract

We present a method for automatized detection and analysis of quasi-periodic lineament structures from images at pixel precision.
The method exploits properties of the images’ frequency domain found by using the Fourier transform. We developed this method
with the goal of detecting lineament structures in an image of the Hathor cliff of comet 67P/Churyumov–Gerasimenko, which are
caused by layerings and furrows in the nucleus material. Using our method, we determined the orientation and wavelength range
of these structures. The detected layering edges have similar orientations and spatial separations of 9–20 m, and are ubiquitous
throughout the image. We suggest that the layerings are a global feature of the comet nucleus that provide information about
formation and evolution of comet 67P. The furrows are non-uniformly distributed throughout the image. Their orientation is
broadly parallel to the direction of the local gravity vector at the Hathor cliff, with spacings similar to those of the layering
structures. The furrows are interpreted as signatures of local down-slope movement of cliff material. We demonstrate that the
developed method is broadly applicable to the detection and analysis of various kinds of quasi-periodic structures like geological
layering, folding and faulting, and texture analysis in general. In order to facilitate the application of our method, this paper is
accompanied by a demo program written in MATLAB.