Aerosol data from the High Altitude Lidar Observatory (HALO), pictured here, will give mission scientists a better sense how Doppler Aerosol Wind Lidar (DAWN) is working and what its strengths and weaknesses are.

The High Altitude Lidar Observatory (HALO) instrument head, which houses the lidar instrument, is installed onto the DC-8 airborne science laboratory at NASA Armstrong Flight Research Center in Edwards, California. The gold and blue casing holds the laser, optics, detectors, and electronics, which are at the heart of the lidar.

The High Altitude Lidar Observatory (HALO) system electronics and diagnostic tools are integrated onto the DC-8 airborne science laboratory at NASA Armstrong Flight Research Center in Edwards, California. The lidar system control electronics are on the right hand side of the rack. The large monitors on the left are used to display real-time images of water vapor and aerosol profiles, which are used by the science team to guide in-flight decisions and navigation. The compact HALO instrument head can be seen directly behind the electronics rack.