[PPS01-P03] JUICE 搭載ガニメデレーザー高度計 (GALA) - 概要およびプロジェクト進捗
キーワード：GALA、JUICE、Jupiter、Ganumede、レーザ高度計
We present an introduction, current status, and role of the Japan team for the Ganymede Laser Altimeter (GALA) for the Jupiter Icy Moon Explorer (JUICE) mission. JUICE is a mission of ESA to be launched in 2022, and GALA is one of the payloads of JUICE.
Major objectives of GALA are to provide topographic data of Ganymede, the largest satellite of Jupiter, and to measure its tidal amplitudes. The latter is crucially important to detect and to characterize an underground ocean on Ganymede. Furthermore, GALA supports geological studies, e.g., identification of characterization of tectonic and cryo-volcanic regions, impact basins, and craters. GALA also provides information on surface roughness and the albedo.
For the laser altimetry, GALA emits and receives laser pulses at about 500 km altitude above Ganymede. Wavelength, energy, and repetition frequency of the laser plus are 1064 nm, 17 mJ, and 30 Hz, respectively. Reflected beam from the Ganymede surface is received by the receiver telescope with 25 cm diameter aperture, re-focused by the BEO including a narrow band-pass filter, and then detected by the APD detector.
Development of GALA is carried out in international collaboration by Germany, Japan, Switzerland, and Spain. GALA-Japan will develop the Backend Optics (BEO), the Focal Plane assembly (FPA) including an avalanche photo-diode (APD) detector, and the Analog Electronics module (AEM) in the receiver chain.
Major objectives of GALA are to provide topographic data of Ganymede, the largest satellite of Jupiter, and to measure its tidal amplitudes. The latter is crucially important to detect and to characterize an underground ocean on Ganymede. Furthermore, GALA supports geological studies, e.g., identification of characterization of tectonic and cryo-volcanic regions, impact basins, and craters. GALA also provides information on surface roughness and the albedo.
For the laser altimetry, GALA emits and receives laser pulses at about 500 km altitude above Ganymede. Wavelength, energy, and repetition frequency of the laser plus are 1064 nm, 17 mJ, and 30 Hz, respectively. Reflected beam from the Ganymede surface is received by the receiver telescope with 25 cm diameter aperture, re-focused by the BEO including a narrow band-pass filter, and then detected by the APD detector.
Development of GALA is carried out in international collaboration by Germany, Japan, Switzerland, and Spain. GALA-Japan will develop the Backend Optics (BEO), the Focal Plane assembly (FPA) including an avalanche photo-diode (APD) detector, and the Analog Electronics module (AEM) in the receiver chain.