The Ganymede Laser Altimeter (GALA) for JUpiter ICy moons Explorer (JUICE)Project

The Ganymede Laser Altimeter (GALA) of JUpiter  ICy moons Explorer (JUICE) of European Space Agency is jointly developed by an international team from Germany, Japan, Switzerland and Spain. GALA measures a distance between the position of JUICE spacecraft and sub-spacecraft point by time-of-flight where the signal that the transmitted laser pulse is reflected by the surface of Ganymede, which is an icy satellite, and it is detected by an optical sensor called an avalanche photodiode (APD) and then it derives difference in level, dip angle and local albedo of the Ganymede surface. From those observation data, we may elucidate the internal structure of Ganymede. PERC is responsible for the development of APD and analog electronics modules (AEM).