The OSIRIS-REx Laser Altimeter (OLA) is a two-axis scanning lidar (Light Detection and Ranging) instrument that will
         provide high-resolution topographical information throughout the entire mission. OLA has a single common receiver and two 
         complementary transmitter assemblies, which enhance the resolution of its data. OLA?s high-energy laser transmitter (HELT) 
         is used for ranging and mapping from 1 to 7.5 km and collects returns at 100Hz. The low-energy laser transmitter (LELT) collects
         returns at 10kHz and is used for ranging and imaging at smaller distances (~200 m to 1 km). The repetition rate of these
          transmitters sets the data acquisition rate of OLA. Laser pulses from both the low and high energy transmitters are directed onto 
          movable scanning mirror, which is co-aligned with the field of view of the receiver telescope limiting the effects of background 
          solar radiation. Each pulse provides target range, azimuth, elevation, received intensity and a time-tag.