12:00 〜 12:15
[PPS07-06] Mapping small-scale craters of Phobos' surface from restored Mars Express SRC images
Topographic irregularities at lander scale (e.g., small craters, boulders, grooves, etc.) should be identified as many as possible for future landing missions, such as the Martina Moons eXploration [1]. On 23rd July 2008 (orbit 5851) and 9th January 2011 (orbit 8974), the Mars Express spacecraft obtained the highest-resolution (~0.9 m/pixel) images of Phobos surface by the Super Resolution Channel (SRC [2]) of the High-Resolution Stereo Camera (HRSC [3]). Despite higher ground sampling distances, previous studies have not investigated these SRC images because they contain severe pepper noises and motion smears, which substantially frustrates the achievements of image-based studies and high-resolution image products. We thus aim to characterize smaller craters on the Phobos surface at a highest-ever resolution by using restored SRC images.
We prepared raw datasets of SRC images, removed pepper noises (“blemish” pixels [2]) from them by using a boxcar filter by means of the USGS ISIS software, and applied a simple deconvolution assuming a linear point spread function (PSF) implemented in Python OpenCV and MATLAB, with the help of the expected crater shapes. In this presentation, we report preliminary results of spatial densities of small craters within corrected SRC image footprints and discuss the applicability of our results to the planned landing site selection and/or landing operation of the MMX spacecraft.
1. Takemura, T.; Miyamoto, H.; Hemmi, R.; Niihara, T.; Michel, P. Small-scale topographic irregularities on Phobos: image and numerical analyses for MMX mission. Earth, Planets and Space 2021, 73, 213, doi:10.1186/s40623-021-01463-8.
2. Oberst, J.; Schwarz, G.; Behnke, T.; Hoffmann, H.; Matz, K.D.; Flohrer, J.; Hirsch, H.; Roatsch, T.; Scholten, F.; Hauber, E.; et al. The imaging performance of the SRC on Mars Express. Planetary and Space Science 2008, 56, 473-491, doi:10.1016/j.pss.2007.09.009.
3. Neukum, G.; Jaumann, R. HRSC: The High Resolution Stereo Camera of Mars Express. In Mars Express: The Scientific Payload; ESA: 2004; Volume SP-1240, pp. 17-35.
We prepared raw datasets of SRC images, removed pepper noises (“blemish” pixels [2]) from them by using a boxcar filter by means of the USGS ISIS software, and applied a simple deconvolution assuming a linear point spread function (PSF) implemented in Python OpenCV and MATLAB, with the help of the expected crater shapes. In this presentation, we report preliminary results of spatial densities of small craters within corrected SRC image footprints and discuss the applicability of our results to the planned landing site selection and/or landing operation of the MMX spacecraft.
1. Takemura, T.; Miyamoto, H.; Hemmi, R.; Niihara, T.; Michel, P. Small-scale topographic irregularities on Phobos: image and numerical analyses for MMX mission. Earth, Planets and Space 2021, 73, 213, doi:10.1186/s40623-021-01463-8.
2. Oberst, J.; Schwarz, G.; Behnke, T.; Hoffmann, H.; Matz, K.D.; Flohrer, J.; Hirsch, H.; Roatsch, T.; Scholten, F.; Hauber, E.; et al. The imaging performance of the SRC on Mars Express. Planetary and Space Science 2008, 56, 473-491, doi:10.1016/j.pss.2007.09.009.
3. Neukum, G.; Jaumann, R. HRSC: The High Resolution Stereo Camera of Mars Express. In Mars Express: The Scientific Payload; ESA: 2004; Volume SP-1240, pp. 17-35.