Optical system design and integration of the Global Ecosystem Dynamics Investigation Lidar

摘要

The Global Ecosystem Dynamics Investigation (GEDI) instrument was designed, built, and tested in-house at NASA’sGoddard Space Flight Center and launched to the International Space Station (ISS) on December 5, 2018. GEDI is a multibeamwaveform LiDAR (light detection and ranging) designed to measure the Earth’s global tree height and canopydensity using 8 laser beam ground tracks separated by roughly 600 meters. Given the ground coverage required and the 2year mission duration, a unique optical design solution was developed. GEDI generates 8 ground sampling tracks from 3transmitter systems viewed by a single receiver telescope, all while maximizing system optical efficiency and transmitterto receiver boresight alignment margin. The GEDI optical design, key optical components, and system level integrationand testing are presented here. GEDI began 2 years of science operations in March 2019 and so far, it is meeting all of itskey optical performance requirements and is returning outstanding science.