GRAAL: Geospatial Rastering And Atmospheric Lidar

To meet critical science needs for the upcoming decade in Earth Observation, new technologies are required that reduce lidar size, weight, power, and cost while retaining efficiency, reliability, lifetime, and high performance. This is a challenging problem as state-of-the-art space based lidar systems operate at the edge of physical limits. We propose to develop the Earth Compact lidar for Height and altitude Observations (GRAAL). GRAALis an ultra-compact time-of-flight ranging lidar for Earth observation from Low Earth Orbit (LEO), designed to address key observational priorities including ice sheet thickness, forest canopy thickness, and smoke and cloud cover. GRAAL delivers similar science performance to ICESat-2rsquo;s ATLAS lidar instrument using. a radically new optoelectronics concept with two critical advances: 1) a greater than 10x reduction in size, weight, power, and cost by using a novel optical architecture; 2) GRAAL#39;s optical path inherently provides a dual-channel capability for multi-sensor configurations such as imaging + lidar or hyperspectral sensing + lidar. With these two advances, GRAAL will be a key enabling technology for the next decade of compact lidar systems tasked with providing high quality data while vastly reducing instrument cost, size, and complexity. We have designed GRAAL as a ldquo;stockrdquo; lidar system replacing expensive, long-lead custom designs such as ATLAS, which will enable new mission architectures that require cost-effective global coverage and improved responsiveness to dynamic events, for example in constellations of SmallSat-scale satellites.