3 October 2007 New concept design of differential absorption lidar: fusion of DIAL and TDLS methods
Author Affiliations +
Abstract
We propose a new approach to range-resolved remote gas sensing in the atmosphere based on a combination of a DIAL and tunable-laser diode spectroscopy (TDLS) methods. To add range-resolving capabilities to a TDLS sensor we propose to arrange a group of retroreflectors (RRs) dividing an absorption path into adjacent measurement sections similar to those utilized by conventional DIAL systems. We implemented two techniques for the interrogation of the RRs: 1) scanning a beam of a continuous-wave laser over RRs sequentially; 2) using a time delay between returns from different RRs illuminated with a pulsed laser. We employed scanning technique with a vertical-cavity surface-emitting laser (VCSEL) operating near 1389 nm. A single-pulse interrogation method was demonstrated with a 10.9-&mgr;m quantum cascade laser (QCL) suitable for detection of ammonia, ethylene and water vapor in the atmosphere. Gas sensing and ranging was performed over distances varying from ~ 1 m up to ~ 1 km. Using VCSEL we attained a 0.5-s time resolution in gas concentration profiling with a 10-cm spatial resolution. Minimum interrogation time of a group of RRs was ~ 9 ms. A new generation of differential absorption LIDARs can be developed for range-resolved gas sensing in the atmosphere over distances up to ~ 1 km. The instruments can be used for a variety of applications ranging from fencing industrial areas to monitor fluxes of atmospheric pollutants to continuous air quality control in populated areas
© (2007) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Alexandre Lytkine, Brian Lau, Alan Lim, Wolfgang Jaeger, John Tulip, "New concept design of differential absorption lidar: fusion of DIAL and TDLS methods", Proc. SPIE 6750, Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing III, 67500C (3 October 2007); doi: 10.1117/12.737436; https://doi.org/10.1117/12.737436
PROCEEDINGS
12 PAGES


SHARE
Back to Top