Flash LIDAR Spatial Resolution and Range Improvements for EDLApplications

Several up-coming NASA lunar and planetary exploration missions are planning to use state-of-the-art 3D Hazard Detection (HD) and 3D Hazard Relative Navigation techniques to significantly reduce the risks associated with Entry, Decent, and Landing (EDL) operations. 3D Imaging / ranging sensors with improved range, wide-field-of view (WFOV), and instantaneous field-of-view (IFOV) are highly desired to enable the landers to access difficult to reach, science rich landing zones.nbsp; Global Shutter Flash (GSF) LIDAR has emerged as one of the 3D EDL relative navigation sensors of choice due to its superior real time 3D mapping capabilities. Recent GSF-LIDAR improvements have focused on WFOV and IFOV performance using smaller pixels and larger focal plane array formats. However, smaller pixels degrade LIDAR range performance. Increasing range performance using higher energy lasers is problematic due to the severe size, weight, and power penalties. These SWAP penalties can be avoided by improving the LIDAR detector photo-electrical gain. Range performance is proportional to the square-root of detector photo-optical gain. Existing GSF-LIDARs use InGaAs APD technology. The effective photo-optical gain is the product of the intrinsic quantum efficiency. Typical linear mode InGaAs APD gains range from 1 to 10.nbsp; Recent advancements in AlxIn1-x AsySb1-y indicate that linear mode photo-optical gains greater than 100 can be achieved with minimal noise degradation. Thus GSF-LIDAR imaging / ranging detectors with improved WFOV, IFOV, and range 1.7X range performance with no additional laser energy requirement. ASC is proposing to develop an AlxIn1-x AsySb1-y detector design optimized for 1064nm operation. In addition, ASC is planning to perform performance measurements on existing AlxIn1-x AsySb1-y 100um single element APDs. Using this information, the focus of the Phase II program is fabricate and evaluate the ranging /imaging 32x32 element GSF-LIDAR focal plane test chip.