NASA Successfully Tests CASALS Airborne Prototype to Create Continuous 3D Maps of Earth's Surface

NASA researchers have developed a new instrument designed to eliminate large unmapped gaps in satellite data by creating continuous three-dimensional maps of Earth's surface. Built at NASA’s Goddard Space Flight Center, the Concurrent Artificially-intelligent Spectrometry Lidar System (CASALS) uses a compact design to sweep large swaths of terrain without relying on heavy motorized mirrors.

Instead of mechanical steering, CASALS uses a tunable seed laser that cycles through 256 unique wavelengths. An optical component called a transmission grating bends the light at varying angles based on wavelength, steering each pulse into a distinct position across the flight path. The system also features a detector array with an 80 percent quantum efficiency, allowing it to detect weaker return signals from dark surfaces or dense vegetation.

An airborne prototype successfully flew on a NASA aircraft over Delaware’s Great Cypress Swamp in November 2024. Operating at an altitude of five kilometers, the system achieved a 22-centimeter horizontal resolution, capturing detailed data on vegetation structures and ground elevation. The research team plans to fly the instrument again during the ASCENT campaign in summer 2027.

Before building a space-ready version, researchers aim to widen the instrument's swath and add onboard data processing software.