17:15 〜 19:15
[PPS08-P02] MBC’s Calibration Summary and Data Archive
キーワード：SLIM、MBC、Lunar Exploration
SLIM spacecraft was successfully landed on the Moon at January 20th 0:20 (JST). After landing, we obtained the multi-band spectral data of 10th boulders, which might be eject from SHIOLI crater, using Multi-Band Camera (MBC). MBC is a compact VIS-NIR camera composed of an imaging sensor (Vis-InGaAs), a filter-wheel with 10 band-pass filters, a telephoto focusable optical system, and a movable mirror for panning and tilting. The observed bands were 750 nm, 920 nm, 950 nm, 970 nm, 1000 nm, 1050 nm, 1100 nm, 1250 nm, 1550 nm and 1650 nm, which coverd the characteristic absorption bands of lunar minerals.
There are five steps in MBC data calibration, dark correction, removal of contamination shadows in the optical path observed in the image, calculate relative reflectance, calculate band ratio (remove continuum), and color aberration correction using pattern matching. To calibrate the dark level, which depends on sensor temperature, the new dark field images was calculate to each images using only postlanding data. In the optical path of MBC, there is some dust particles, and the transmittance of optical path was affected. There is high possibility that these particles exist on each Band Pass Filters. Because… The position of dust shadows in the images varies between BPFs. The transmittance is decreased. The shape is NOT change in each data. After dark correction, the contamination shadows observed in each image were removed. At this timing, the images are still digital number. Digital numbers were converted to relative reflectance using preflight calibration data, which obtained using a barium sulfate integrating sphere at JAXA. Then, a continuum, which is linear connected the relative reflectance value between 750 nm and 1550 nm, was removed. And the scientific parameters (e.g. absorption intensity, band position) were calculated for each pixel. Finally, pattern matching was conducted. Pattern matching was performed to correct positional shifts dependent on wavelength differences. In this presentation, we will outline the MBC calibration and data archives.
There are five steps in MBC data calibration, dark correction, removal of contamination shadows in the optical path observed in the image, calculate relative reflectance, calculate band ratio (remove continuum), and color aberration correction using pattern matching. To calibrate the dark level, which depends on sensor temperature, the new dark field images was calculate to each images using only postlanding data. In the optical path of MBC, there is some dust particles, and the transmittance of optical path was affected. There is high possibility that these particles exist on each Band Pass Filters. Because… The position of dust shadows in the images varies between BPFs. The transmittance is decreased. The shape is NOT change in each data. After dark correction, the contamination shadows observed in each image were removed. At this timing, the images are still digital number. Digital numbers were converted to relative reflectance using preflight calibration data, which obtained using a barium sulfate integrating sphere at JAXA. Then, a continuum, which is linear connected the relative reflectance value between 750 nm and 1550 nm, was removed. And the scientific parameters (e.g. absorption intensity, band position) were calculated for each pixel. Finally, pattern matching was conducted. Pattern matching was performed to correct positional shifts dependent on wavelength differences. In this presentation, we will outline the MBC calibration and data archives.