Shinsuke Kodama

The global distribution of pure anorthosite on the Moon

It has been thought that the lunar highland crust was formed by the crystallization and floatation of plagioclase from a global magma ocean, although the actual generation mechanisms are still debated. The composition of the lunar highland crust is therefore important for understanding the formation of such a magma ocean and the subsequent evolution of the Moon. The Multiband Imager on the Selenological and Engineering Explorer (SELENE) has a high spatial resolution of optimized spectral coverage, which should allow a clear view of the composition of the lunar crust. Here we report the global distribution of rocks of high plagioclase abundance (approaching 100 vol.%), using an unambiguous plagioclase absorption band recorded by the SELENE Multiband Imager. If the upper crust indeed consists of nearly 100 vol.% plagioclase, this is significantly higher than previous estimates of 82–92 vol.% (refs 2, 6, 7), providing a valuable constraint on models of lunar magma ocean evolution.

Preflight and In-Flight Calibration of the Spectral Profiler on Board SELENE (Kaguya)

The Spectral Profiler (SP) is a visible-near infrared spectrometer on board the Japanese Selenological and Engineering Explorer, which was launched in 2007 and observed the Moon until June 2009. The SP consists of two gratings and three linear-array detectors: VIS (0.5-1.0 μm ), NIR 1 (0.9-1.7 μm), and NIR 2 (1.7-2.6 μm). In this paper, we characterize the radiometric and spectral properties of VIS and NIR 1 using in-flight observational data as well as preflight data derived in laboratory experiments using a calibrated integrating sphere. We also proposed new methods for radiometric calibration, specifically methods for nonlinearity correction, wavelength correction, and the correction of the radiometric calibration coefficients affected by the water vapor. After all the corrections, including the photometric correction, we obtained the reflectance spectra for the lunar surface. Finally, we examined the stability of the SP using the SP data near the Apollo 16 landing site observed at four different times. The difference in reflectance among these four observations was less than ~ ±1% for most of the bands, suggesting that the degradation of the SP is not significant over the mission period.

Scientific exploration of lunar surface using a rover in Japanese future lunar mission

Abstract A new lunar mission (SELENE-B) including a lander is now in consideration in Japan. The mission will follow up SELENE (SELenological and ENgineering Explorer, a global remote sensing mission of the moon in 2004). Scientific investigation plans using a rover are proposed: exploration of a crater central peak to discover subsurface materials and exploration of the polar region to discover the trapped ice. We have already developed a 5-wheel engineering-model rover, Micro5, which has a long manipulator with a camera on top. The rover can climb over 15cm steps and rocks by a new suspension system PEGASUS.

Coseismic displacement measurement of the 2010 El Mayor, Mexico earthquake by subpixel correlation from optical satellite images

In order to grasp the quantitative and spatial information of the earth surface deformation due to earthquakes, well-georectified remotely sensed data with high pixel resolution taken before and after the event are useful. Among satellite optical sensors, Terra and PRISM loaded on Terra and ALOS, respectively, have the function of along-track stereoscopic shooting to generate a digital elevation model (DEM), then an orthorectified image based on derived DEM is also created by a single fight observation. This paper performs to apply the subpixel-based image processing using pre- and post-earthquake orthorectified images to map the displacement distribution around the fault rupture region of the 2010 El Mayor (Baja) earthquake.

Calibration of NIR 2 of Spectral Profiler Onboard Kaguya/SELENE

The Spectral Profiler (SP) is a visible-near infrared spectrometer onboard the Japanese Selenological and Engineering Explorer (SELENE), which was launched in 2007 and observed the Moon until June 2009. The SP consists of two gratings and three linear-array detectors: VIS (0.5-1.0 μm), NIR 1 (0.9- 1.7 μm), and NIR 2 (1.7-2.6 μm). In this paper, we propose a new method for radiometric calibration of NIR 2, specifically for the dark output (background) estimate, which is different from the previous method used for VIS and NIR 1. We show that the reflectance spectra of NIR 2 derived from the new radiometric calibration show less noise than those of the previous method. Based on an analysis of the reflectance spectra at exposure sites of the end-member minerals on the lunar surface, we demonstrated that the spectral features of the 2-μm band in the NIR 2 spectra are consistent with those expected from the minerals inferred from the features of the 1-μm band in the VIS and NIR 1 spectra. Finally, we examined the repeatability of the radiometric calibration of NIR 2 using the SP data near the Apollo 16 landing site observed at four different times. The typical difference in the reflectance at wavelengths <;~2.1 μm was a few percent, which is within the uncertainty due to the error in the background estimate, suggesting that there was no significant change in the sensitivity of NIR 2 over the mission period.

Aster Digital Elevation Model and orthorectified images generated on the GEO Grid

The ASTER on-demand processing service, which provides a Digital Elevation Model (DEM) and orthorectified images was developed and deployed on the GEO Grid system. It is designed to support the latest algorithms for radiometric and atmospheric corrections developed by researchers as well as the geometric correction and other DEM processing options. The functions and options in this service are developed and implemented as modules, so that they can be arranged as the user requires. Although the system is an experimental, it can provide higher quality data sets than the standard products.

Development of ALOS/PALSAR data on-demand processing and providing system on GEO Grid

GEO Grid has been proposed by AIST in order to contribute to earth science.?? GEO Grid mainly provides satellite and field observation data related to earth science through data search service, data processing service and data providing service. Recently, we have developed ALOS PALSAR data on-demand processing and providing system as one of GEO Grid data providing system. The system allows users to easily search and quickly receive PALSAR products without careful considerations and advanced skills. There are two important points in the system. One is seamless connection between AIST and an external archive system. The other is that the system can provided calibrated PALSAR products according to observations using Corner Reflectors. As a future plan, OGC-CSW is applied to this system for data search service.

Study on Absolute Calibration Coefficient Improvement for ALOS PALSAR Data after Initial Calibration Check

The Advanced Land Observing Satellite (ALOS) was launched in 2006, carrying the Phased Array type L-band Synthetic Aperture Radar (PALSAR). Although three years have passed from the start of ALOS PALSAR observation, we know the PALSAR is in operation with greatly stability operation. However, we need to monitor its performance for the future sustainable operation in order to evaluate the temporal sensitivity variations of the PALSAR sensor and keep the calibration coe-cient quality and its improvement. To achieve this goal, AIST (National Institute of Advanced Industrial Science and Technology) kicked ofi the PALSAR calibration and validation campaign in 2007. We especially focus on cross-polarization calibration and aim to propose an improved backscattering coe-cient by evaluating the absolute calibration coe-cient accuracy is evaluated, which is calculated for each polarization based on the ground- truth. In the calibration observations, we used two triangular trihedral corner re∞ectors (CRs) of size 2m and 3m for the like-polarization and our inbuilt prototype rotatable rectangular dihedral CR was used for the cross-polarization.