Description: An eye-safe, multispectral cross-track scan subsystem with a large receiver aperture and a narrow FOV is proposed for the NASA Cloud Physics Lidar to increase horizontal area coverage. The +/-15 degree cross-track scan capability will cover +/- 5 km from nadir at a 20 km altitude. The cross-track scanner uses a whiskbroom pattern with three simultaneous scans and independent receiver FOV's which provides 30,000 points per sweep. Solar background is reduced with a narrow bandpass filter and a narrow transmitter linewidth with center wavelength control. The scanner accounts for the return pulse lag angle due to pulse time of flight. Vertical resolution is maintained at 30 m. Photon counting SPAD detectors and PMT's are used with photon counting modules and multichannel scalers.

Benefits: This technology provides a scanning solution to increase the horizontal scanning area for the CPL lidar system used in NASA Earth Science missions. The mission is remote sensing of atmospheric clouds and aerosols, and cloud-aerosol interactions. The CPL system operates from the Global Hawk, ER-2 and Proteous platforms. The transmitter/scanner subsystem is scalable to operate in applications such as remote sensing from Satellites.

Commercial and military applications for a UAV based compact, efficient, wide field of regard scanning lidar include active multispectral imaging for day night missions such as crop management, forest and forest fire management, 3D imaging for law enforcement, and Imaging Laser Altimetry. Sensor fusion is also possible with this scan approach and would enable simultaneous thermal imaging and UV, visible, and/or NIR imaging with high 3D resolution in a compact, efficient scanning lidar that could operate at high altitude with a large field of regard.