Abstract
A diversified and interdisciplinary lidar research program has been pursued during the recent 10 years at South China Normal University in Guangzhou, China. The activities include time-of-flight (TOF) lidar applications with pulsed lasers for differential absorption (DIAL), laser-induced fluorescence (LIF), and laser-induced break-down spectroscopy (LIBS) studies. Further, range-resolving (bi-static) lidars, based on Scheimpflug arrangements, have been employed. Mobile, drone-based, and hand-held systems were developed. Monitoring has been directed toward air pollutants, vegetation and crops, flying insects (agricultural pests and disease vectors), and water pollutants and fauna.
A mobile TOF lidar system was developed as a multipurpose platform for field work. A special adaption of the system is range-resolved monitoring of atomic mercury (absorbing around 254 nm) using the DIAL approach. A high-light was the mapping of mercury fumes from the underground burial chamber of the “Terracotta Army Emperor” Qin’s mausoleum in Xi’an. Further, mercury in major cities as well as in a mining areas was studied. Remote LIF studies included corn and rice fields and concerned species characterization and fertilizer levels.
Two different compact LIF systems carried by a drone were developed for vegetation and water pollution studies, with typical flying heights of tens of m. The vegetation probing system and an underwater LIF monitoring system provide range-resolution combined with full-spectral recordings. Such systems could be complemented with compact hand-held instrumentation.
Scheimpflug CW lidar systems are powerful in monitoring flying insects. Characteristic information on reflectance, depolarization, and wing-beat frequencies can readily be obtained.
