SIMPL is an advanced-technology airborne laser altimeter developed through NASA’s ESTO Instrument Incubator Program. Simultaneously measures surface topography, roughness and slope as well as scattering properties to differentiate surface types. SIMPL is a technology and remote sensing pathfinder for next-generation, high-efficiency, spaceflight laser altimeters. Developed with a focus on ice sheet elevation and its change, sea ice thickness and its change, and icy moon surface processes.