Title: 2-micron triple-pulse integrated path differential absorption lidar development (IPDA) for simultaneous airborne column measurements of carbon dioxide and water vapor in the atmosphere
Presenting Author: Upendra N. Singh
Organization: NASA Langley Research Center
Co-Author(s): Mulugeta Petros, Tamer F. Refaat, Jirong Yu, Charles W. Antill, Ruben Remus, Hyung Lee, Jane Lee, Syed Ismail, Karl Reithmaier and Kenneth J. Davis

Abstract:
This presentation will provide status and details of an airborne 2-micron triple-pulse integrated path differential absorption (IPDA) lidar being developed at NASA Langley Research Center with support from NASA ESTO Instrument Incubator Program. The development of this active optical remote sensing IPDA instrument is targeted for measuring both atmospheric carbon dioxide and water vapor in the atmosphere from an airborne platform. Wavelength selection and laser transmitter operation allows measuring both species independently and simultaneously. This is the first demonstration of measuring two different atmospheric molecules with a single instrument. The basic instrument design is based on knowledge gathered through the previously successful 2-micron double-pulse IPDA. Critical enhancements are being implemented in the new triple-pulse design that significantly advances the state-of-the art technology. For the transmitter, modifications include triple-pulse operation of the laser, a semiconductor seed laser of narrow line width, laser timing control updates and wavelength control design. For the receiver, updates includes the data acquisition system and additional high performance e-APD detector. The e-APD detector supplied by NASA GSFC, is a state-of-art, space qualifiable device, which has already been validated by GSFC for lidar applications in the airborne operation. Combining both the 2-micron triple-pulse transmitter with this new detector in a single instrument will result in an advanced state-of-the-art tripled pulsed CO2 IPDA lidar with unique capability of measuring column carbon dioxide and water vapor that will meet or exceed the project space based measurement requirement. This presentation will focus on the advancement of the 2-micron triple-pulse IPDA lidar development. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of seed laser locking, wavelength control, receiver and detector upgrades, laser packaging and lidar integration. Future plan for IPDA lidar system for ground integration, testing and flight validation will also be presented.