Planation surfaces (PS) play a major role in reconstruction of the evolutionary history of landforms in local areas. Thus, objective and consistent mapping of planation surfaces from remotely sensed data (e.g., satellite imagery, digital elevation models (DEMs)) is paramount for interpreting the geomorphological evolution. Due to the lack of dated sedimentary covers and the difficulties of comprehensive field work, the number and age of planation surfaces in the Southwest Hubei (湖北) Province of China are still controversial. In order to map the PS in the study area, four data visualization techniques including ETM+ false color composite, grey-scale DEM, shaded relief model (SRM) and painted relief model (PRM) were examined. It is found that the PRM is the most optimal technique for planation surface mapping. The study area was successfully mapped by visual interpretation of a PRM derived from ASTER GDEM. The mapped PS was divided into five classes in terms of elevation according to previous studies, varying from 1 700-2 000 (PS1), 1 300-1 500 (PS2), 1 000-1 200 (PS3), 800-900 (PS4) to 500-600 (PS5) m. The results were partially compared with the published works. It is revealed that this method of mapping enjoys a higher accuracy and can reduce the time and effort required in the traditional mapping to a large extent. The results also demonstrated that the PRM is an effective tool for geomorphological feature mapping with considerable accuracy. The preliminary results can serve to facilitate locating rep-resentative samples for the planation surfaces dating, thus to determine the ages of PS in the study areas.
The Lunar Penetrating Radar(LPR)carried by Chang’E-3 has imaged the shallow subsurface of the landing site at the northern Mare Imbrium.The antenna B of the Channel-2 onboard the LPR(LPR Channel-2B)has collected more than 2000 traces of usable raw data.Because of the low resolution and noise of the raw data,only a few shallow geological structures are visible.To improve the resolution and the signal-to-noise ratio of the LPR data,we processed the LPR data including amplitude compensation,filtering,and deconvolution processes.The processing results reveal that the data processing in this study not only improves the signal-to-noise ratio of the LPR Channel-2B data but also makes the geological structures vivid.The processing results will lay the foundation for the subsequent geological interpretation and physical property inversion of lunar materials.
ZHAO NaZHU Pei MinYANG Ke SiYUAN Yue FengGUO Shi Li
