Small Business Innovation Research/Small Business Tech Transfer
Atmospheric Lidar with Cross-Track Scanning
Project 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 (CPL) to increase the horizontal scan area coverage. The /-14 degree cross-track scan capability will cover /- 5 km from nadir at a 20 km altitude. The cross-track scanner uses a bidirectional scan pattern, which collects 10,000 data points per cross track scan at a 5 kHz transmitter rep rate. Solar background is reduced with narrow bandpass filters and a narrow transmitter linewidth with center wavelength control. The scanner accounts for the return pulse lag angle due to pulse time of flight. The existing CPL vertical resolution is maintained at 30 m. Photon counting SPAD detectors and PMT's are used with photon counting modules and multichannel scalers, which support eye-safe operation. The compact receiver telescope design is achieved with a configuration that uses a fixed primary mirror and a scanning secondary mirror, which directs the return signal through a Coude path to the the detector optics bench. The multispectral lidar uses polarization discrimination on two of the three receiver channels, and the optics design supports a 100 urad receiver Instantaneous Field Of View to minimize the solar background noise.
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Anticipated Benefits
This technology provides a scanning solution to increase the cross-track horizontal scan capability of the CPL lidar system used in NASA Earth Science missions. The scanner is scalable to space platforms such as satellites and the International Space Station, and to UAV's. Two Cloud Physics Lidar (CPL) systems are currently operational in the NASA ER-2 and Global Hawk platforms, and have participated in about two dozen missions. The CPL instrument has been operational for over 10 years and is a proven NASA instrument for collecting multispectral atmospheric lidar data at nadir from about 20 km altitude. The LSI scanning lidar instrument will provide aircraft based, off-nadir lidar profiling of clouds and aerosols for the first time, and will bring scanning capability to platforms such as satellites and the ISS. The LSI Phase II prototype integrated into the NASA ER-2 aircraft will provide new capabilities to examine changes in smoke properties along a plume, measure variability of aerosols in urban regions, and measure variability in the shortwave radiation field of clouds.
The LSI compact, efficient scanning lidar technology enables new applications for smaller UAV's with payloads less than 10 lbs, and can also replace some existing lidar systems for manned platforms. Scaling to smaller platforms provides a solution for UAV based corridor monitoring for power lines, pipelines, railroads, and many other applications that are served by larger, higher cost hardware and significantly higher cost manned platforms with greater operating expenses. Commercial and military applications for an affordable UAV based, compact, efficient, and wide field of regard scanning lidar include: 1) active multispectral imaging for day and night missions such as crop management, forest and forest fire management, 2) border security, 3) change detection, 4) 3D imaging for law enforcement, 5) natural disaster assessment, and 6) Imaging Laser Altimetry for topographic mapping. The list of existing and emerging scanning lidar applications is growing rapidly. 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 any altitude with a large field of regard. More »
The LSI compact, efficient scanning lidar technology enables new applications for smaller UAV's with payloads less than 10 lbs, and can also replace some existing lidar systems for manned platforms. Scaling to smaller platforms provides a solution for UAV based corridor monitoring for power lines, pipelines, railroads, and many other applications that are served by larger, higher cost hardware and significantly higher cost manned platforms with greater operating expenses. Commercial and military applications for an affordable UAV based, compact, efficient, and wide field of regard scanning lidar include: 1) active multispectral imaging for day and night missions such as crop management, forest and forest fire management, 2) border security, 3) change detection, 4) 3D imaging for law enforcement, 5) natural disaster assessment, and 6) Imaging Laser Altimetry for topographic mapping. The list of existing and emerging scanning lidar applications is growing rapidly. 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 any altitude with a large field of regard. More »
Project Library
Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| Litespar, Inc. | Lead Organization | Industry | Tucson, Arizona |
Goddard Space Flight Center
(GSFC)
|
Supporting Organization | NASA Center | Greenbelt, Maryland |
Primary U.S. Work Locations
-
Arizona
-
Maryland
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