* Successful color ground surface imaging by earth observation microsatellite RISING-2 succeeds using the High-Precision Multi-Spectral Telescope System (HPT).

* Earth’s surface image at a resolution of approximately 5m, the highest resolution so far in the 50kg class microsatellite.

* In the future, the team is focused on advanced observation using high-precision satellite attitude control, and the world’s first liquid crystal filter.

Background

Development commenced in 2009, with Hokkaido University responsible for the observation equipment, and Tohoku University responsible for the satellite bus system. The 43kg RISING-2 satellite was launched on May 24th on an H-IIA rocket. RISING-2 incorporates a small (38cm in length), light-weight (3kg) High-precision Multi-Spectral Telescope System (HPT). The HPT employs advanced technology including a liquid crystal filter developed in conjunction with the Sendai National College of Technology, and a special ceramic mirror, and was designed for a world-first in imaging using 400 wavelengths and 5m ground resolution.

Post-launch, RISING-2 has succeeded in daylight imaging of cloud patterns, and night-time imaging, with a fish-eye CCD camera (WFC), and recently commenced operations aimed at high-precision imaging using the High-Precision Multi-Spectral Telescope System (HPT).

Study Results

On July 2nd, the HPT was used for taking images of the Japanese archipelago during breaks in the wet season cloud cover, and successfully took a series of high-resolution color (RGB) ground images. Images were taken of an area approximately 2.2km x 3.2km to the south in Minamiuonuma City in southern Niigata Prefecture. The initial objective of a spatial resolution on the ground of approximately 5m was achieved, and represents the world’s highest level of performance for small satellites in the 50kg class. These results were achieved through the combination of the superior sensor technology of the HPT, and the sophisticated attitude control of the satellite bus system. They illustrate to the world that Japanese technology leads in the internationally competitive development of 50kg class satellites, and represent a major step towards practical use of satellites in the class.

Future Prospects

In the future, the team is focused on development of an improved satellite attitude control system for practical observation. A further objective is spectral imaging using the world’s first liquid crystal filter for space applications. This filter permits selection of the wavelength used, and if successful, will provide high-resolution spectral measurement in small satellites equal to that of large satellites.

Yukihiro Takahashi, Professor, Faculty of Science, HU Creative Research Institution Space Mission Center, Hokkaido University

TEL & FAX: +81-11-706-9244

E-mail: smc@cris.hokudai.ac.jp