Yiliang Liu

Mars Surface Change Detection from Multi-temporal Orbital Images

A vast amount of Mars images have been acquired by orbital missions in recent years. With the increase of spatial resolution to metre and decimetre levels, fine-scale geological features can be identified, and surface change detection is possible because of multi-temporal images. This study briefly reviews detectable changes on the Mars surface, including new impact craters, gullies, dark slope streaks, dust devil tracks and ice caps. To facilitate fast and efficient change detection for subsequent scientific investigations, a featured-based change detection method is developed based on automatic image registration, surface feature extraction and difference information statistics. Experimental results which use multi-temporal images demonstrate the promising potential of the proposed method.

Automated Detection of Martian Gullies from HiRISE Imagery

Gully is a type of young geological feature on the Martian surface, and the study of gullies can significantly contribute to understanding of the geologic history of Martian surface. As a large amount of high-resolution orbital images have been acquired, manual identification and extraction of all gullies is tedious and prohibitively time consuming. Therefore, it is desirable to develop automated methods for detection of Martian gullies to support scientific studies of the gullies. This paper presents an automated gully detection method based on mathematical morphology techniques. The method integrates a series of morphological operators, including area opening and closing, Bottom-Hat transformation, and path opening. Experimental results using HiRISE images at six sites demonstrate promising performance with detection percentage from 76 percent to 94 percent.