Title: Ground and airborne testing of an advanced 2-micron triple-pulse IPDA for atmospheric carbon dioxide and water vapor active optical remote sensing
Presenting Author: Upendra Nath Singh
Organization: NASA Engineering and Safety Center (NESC), NASA Langley Research Center
Co-Author(s): Mulugeta Petros, NASA Langley Research Center; Tamer F. Refaat, NASA Langley Research Center; Syed Ismail, Analytical Services and Materials, Inc.; Ken Davis, The Pennsylvania State University

Abstract:
An advanced triple-pulse 2-micron integrated path differential absorption (IPDA) lidar have been developed at NASA Langley Research Center. This instrument relies on high-energy triple-pulse laser transmitter operating at 50 Hz, with 200 µs pulse separation. The IPDA measures both atmospheric carbon dioxide and water vapor, the two dominant greenhouse gases, simultaneously and independently. This is achieved by wavelength tuning of each transmitted pulse separately. The first two pulses are tuned to strong water vapor and carbon dioxide absorptions, while the third pulse is tuned to low absorption. This enhances carbon dioxide and water vapor measurement capabilities, while eliminating interferences. In addition, this technique results in saving complexity and cost required to build two separate instruments for sensing two different species. This paper presents the ground and airborne engineering flight results for this IPDA lidar. IPDA tuning capabilities, future science campaign and potential space applications will be addressed towards accurate carbon dioxide measurements.