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Laser-induced fluorescence is a powerful measurement method for determining the concentration of organic pollutants as well as the amount of algae in water. It can be applied in remote sensing of natural waters and has the advantages of high speed and sensitivity. In this paper, we present a compact handheld fluorosensor system for water quality assessment. The power of the technique is demonstrated in measurements at a river system in South China.

Chinese hybrid rice of different varieties, growing in paddies in the Pingqiao district, north of Xinyang city, Henan province, China, was studied in detailed spectroscopic characteristics using laser-induced fluorescence. The base for the studies was the new South China Normal University mobile lidar laboratory, which was dispatched on site, providing facilities both for laboratory studies using a 405 nm excitation source as well as remote sensing measurements at ranges from around 40 m–120 m, mostly employing the 532 nm output from a Nd:YAG laser. We, in particular, studied the spectral influence of the species varieties as well as the level of nitrogen fertilization supplied. Specially developed contrast functions as well as multivariate techniques with principal components and Fisher’s discriminate analyses were applied, and useful characterization of the rice could be achieved. The chlorophyll content mapping of the 30 zones was obtained with the remote sensing measurements. (Less)

A versatile mobile optical remote sensing system utilizing light detection and ranging (lidar) technology has been constructed and adapted for multidisciplinary environmental monitoring tasks on the Chinese scene. A key application is differential absorption lidar (DIAL) monitoring of distributions of gaseous air pollutants. The system includes a 20 Hz Nd:YAG laser-pumped dye laser, and two vertically looking Newtonian telescopes with diameters of 40 and 30 cm, respectively, over which folding mirrors can be hoisted over the laboratory roof to interrogate the remote target area. Using harmonic pulses from the Nd:YAG laser, remote laser-induced fluorescence (LIF) and laser-induced break-down spectroscopy (LIBS) can be performed. In this way, also water pollutants, vegetation, and soils can be studied. The wide applicability of the new system is illustrated in long-range measurements of atmospheric mercury and sulfur dioxide, and in LIF and LIBS monitoring. Remote passive monitoring of flying insects illustrates the additional functionality of the system.