Low SWAP LIDAR Instrument for Arctic Ice Sheet Mass Balance Monitoring

The U.S. Arctic continues to be one of the most difficult places on Earth for year-round scientific observations and research, and ice sheet and sea level changes have been explicitly identified as a current priority in the Presidents Climate Change Science Program, the Arctic Climate Impact Assessment, the 4th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), and other national and international policy documents. Therefore the DOE Atmospheric Radiation Measurement (ARM) program continues to expand its footprint in the North Slope of Alaska (NSA) and has identified a need for the increased use of robotic aircraft to meet the growing need for environmental observing in the Arctic. A small sized ( & lt; 1.25 kg) gimbal-mounted LIDAR unmanned aerial vehicles (UAV) compatible instrument optimized for measuring ice sheet mass balance, as well as land topography and vegetation characteristics in the artic, and which will allow routine data products reporting across all regions and for all seasons. The instrument will consist of a robust laser-based system to measure distance, a Global Positioning System (GPS) receiver, and a single photon sensitive avalanche photodiode (APD) focal plane array (FPA), FPGA data processor and UAV communications/navigation interface processor. The laser will transmit high repetition rate (10 kHz), low pulse energy, short (1.5 to 4 ns) near-infrared pulses that are spatially distributed via holographic optics into a favorable surface microbeam patterns, so that range can be measured along dense in-track and cross-track sampling patterns. The optical pulse returns will be collected with a ~1.5-cm aperture, detected by a single-photon sensitive APD focal plane, time stamped, and stored as a geo-referenced vector. The mission requirements, including environmental conditions; flight duration, altitude range, scan patterns and coverage, and data package will be developed. The requirements document will be used to update the lidar instrument design, and each of the components, including optics, laser transmitted, detector, and pulse processor will be designed. An end-to-end simulation of the system will be performed which takes into account the atmospheric effects, surface reflectance properties, background sources, as well as the individual component performance specifications. Platform jitter and attitude uncertainty will be included. A preliminary design review (PDR) will be conducted, so that in Phase II, a fully-functional system can be fabricated, tested, and demonstrated. Commercial Applications: Geo-referenced lidar can be used for a variety of applications, including 3D mapping, intelligence gathering, site survey and mapping, and military surveillance, reconnaissance, and targeting.