[S-RD24] Cutting-edge sensing technology applied to geology and resource exploration

[SRD24-05] Development of geological and resource survey methods using micro-satellites

*Yukihiro Takahashi¹ (1.Department of Cosmosciences, Graduate School of Science, Hokkaido University)

Keywords:micro-satellite, geological and resource survey, spectral reflectance, spectral library

Measuring the spectral reflectance of rocks and soil exposed on the surface of the earth is not only useful for estimating surface materials, but it is also expected to make a significant contribution to the exploration of resources buried underground. Handheld and drone-mounted spectrometers have their own roles to play, but drones are clearly not enough to survey vast expanses of land. For example, surveying the Gobi in Mongolia at a rate of 100 ha per day would take more than 3,500 years to complete. Satellites can increase the range of observation by an order of magnitude compared to drones, but satellites that can measure detailed reflectance spectra are generally expensive and there are only a limited number of them. In addition, the fact that spectral reflectance is greatly dependent on the relationship between the angle of solar irradiation and the direction of the observation device's field of view also imposes restrictions on satellite observation. This is because if you try to cover areas other than directly below the satellite by widening the field of view of the satellite-mounted camera, the spectral reflectance will change significantly and you will not be able to obtain precise information. In order to overcome these difficulties, our group aims to efficiently measure from multiple angles, build a complete spectral library that takes into account angle dependence, and operate a unique spectral observation satellite based on this. In order to build a spectral library, in addition to developing and using goniometers and high-performance drones outdoors, we are also developing and operating a fully automated bidirectional reflectance distribution function measurement device that includes spectral information indoors. In this presentation, we will introduce the construction of a new geological and resource survey method, from the construction of a ground-based spectral library to the operation of our own satellite.