[PPS03-P30] Effect of the surface terrain on the albedo observation by Hayabusa2 LIDAR and its correction
Keywords:LIDAR, albedo, C-type asteroid, Hayabusa2
In this observation, we have to notice deformation of the returned pulse due to the surface topography. Usually, the returned pulse may be elongated in time and/or attenuated depending on inclination and shape of the reflecting surface. Then, measured intensity of the received pulse can vary with deformation of the returned pulse due to the characteristic of the measurement circuit in the LIDAR even if the normal albedo does not change. We have to correct for the effect to derive accurate albedo.
In this study, we have firstly simulated shape of the deformed returned pulse using possible asteroidal terrain model and feature of the transmitted pulse of the LIDAR. Furthermore, we have investigated the response of the receiver including the measurement circuit for the simulated pulses using LIDAR-EM (Engineering Model). In the experiment, the laser transmitter developed in Chiba Institute of Technology was applied to produce the input pulse. In this presentation, we will report the results of the numerical simulation and the experiment. Then, we discuss how we can correct for the effect of the surface terrain on the measured intensity data of the received pulse.