High cirrus clouds have large influence on weather and climate, and its lidar ratio is an important optical property. Suppose that there is only molecules without aerosol above and below the clouds, the transmittance and optical thickness of clouds can be retrieved from lidar data, and the lidar ratio of clouds. Analysis was performed on the clouds data acquired from 532nm lidar of Hampton University. Observation was performed from January to October 2007. 798 samples with optical thickness between 0.08 and 1.5 were selected. Results show that cirrus clouds observed are mostly in 7~13.5 km altitudes. The lidar ratio is 21.4sr in average, the change of the lidar ratio with season is not obvious, the probability distribution function of lidar ratio appears normal distribution feature. The probability distribution function of optical thickness indicates that most clouds are thin clouds.

Velocity components and temperature data are measured using 50 Hz three-dimensional ultrasonic anemometer during January 2011. Characteristics of the turbulence spectra are calculated and analyzed under different stability over Hefei area. Comparing with other experiment results, curve fitting formulae, diverse instance of the power spectra peak position and tail raising of temperature spectra were obtained. And, two different refractive index structure parameter C2n were measured and compared by hot wire anemometer and sonic anemometer(double-point and one-point method) above a uniform ground. The results obtained by two methods agree well.

The absorption spectral parameters are important when the parameters are used to sense and model the atmospheres of the Earth and the outer planets, especially in low temperature. Sometimes CH4 parameters listed in the HITRAN database are uncertain to some extent. In order to measure the low temperature absorption spectroscopy of methane, a newly developed cryogenic cell by ourselves was used in combination with a distributed feedback (DFB) diode laser as the light source and low temperature absorption spectroscopy of methane at 1.65 μm were measured. The low temperature absorption spectroscopy of methane at 6039.70 cm-1 is given for example and the method to measure the temperature-dependent exponent of self-broadening coefficient of methane are discussed.

During the Sixteenth Guangzhow Asian Games multi-axis differential absorption spectrometers (MAX-DOAS)were used to monitor the atmospheric pollutants real-time in Guangzhou. As the atmospheric conventional and important pollutants, the daily change characteristics of SO2 and NO2 are discussed and further analyzed respectively. By combining meteorological conditions and the important pollution sources around Guangzhou the comprehensive regional pollution transport is analyzed. And it shows that the industrial area located in southeast of Guangzhou plays an important role in the pollution transport, among which SO2 is especially remarkable. The analysis of NO2 profile results shows that the pollutants mainly located in 1km below, and the high pollution layer mainly located in 0.5 km below.

The atmospheric fine particles meter(FPM) was used for continuously in-line monitoring of atmospheric fine particles spectrum during the 2010 Guangzhou Asian Games and Paralympic Games in Guangzhou city and Guangzhou surrounding areas. Characteristics of the partical number concentration curve were analysed.The diurnal variation of particle number concentration was discussed. And the number of particles’ diurnal variation in each mode concentration was discussed respectively. The results show that atmospheric aerosol particles are mainly concentrated in the smaller particle size. The results show that the nucleation mode particles are affected by the process of nucleation and traffic emissions. The curve show a single peak in Guangzhou city station and three-peak in Heshan station. Atiken mode particles are impacted by human activities and nucleation mode particles with curve of three-peak distribution in Guangzhou city station and two-peak distribution in Heshan station. Accumulation mode particles and coarse particle mode particles has a significantly feature that the concentration was lower during the day and higher in the night. With the effect of splashes of salt coarse particle mode particles’ curve has a peak at night in Heshan station. The effect of the rainfall’s scavenging to particles in atmosphere was discussed.

Three dimensional excitation-emission fluorescence spectra characteristics of influent and effluent from urban domestic sewage treatment plant were analyzed combined with PARAFAC model. The results indicated that urban sewage has four fluorescence centers. The 1 and 2 fluorescent center of influent were obvious. However, 3 and 4 fluorescence centers were blurry. All the four fluorescence centers of effluent were quite obvious. Combining PARAFAC model, both the influent and effluent contain three kinds of fluorescence compositions, which are tryptophan-like、 tyrosine-like and fulvic-like. The scoring values of three kinds of fluorescent compositions can be used as another fluorescence feature of urban sewage. According to the scoring values, tryptophan-like and tyrosine-like are unstable in both influent and effluent, but fulvic-like is relatively stable.

In China, atmospheric mercury pollution is serious and is considered to be the largest mercury quantity emissions in world. Mercury can retain elemental form for a long time in atmosphere, and also can be transmitted for a long-distance. The feasibility studies of the differential optical absorption spectroscopy (DOAS) technology that applied for atmospheric mercury measurement were discussed. First, mercury resonance absorption is studied by the measurement of cells of mercury vapor with different lengths, then the absorption of saturated mercury vapor is analyzed using high-resolution spectrometer. Finally, with the current instrument, the concentration of mercury in air is measured. Through the experiment, main interfering gases are identified, and the requirement of the resolution of spectrometer is ensured. The research result provides advanced technical support for further measurements of mercury in the atmospheric and the mercury of high concentration in flue gas.

The mobile diffrential optical absorption spectroscopy(DOAS) instrument uses a telescope to collect zenith scattered light in the UV or visible region and it was used to derive the vertical column density of trace gases above the measurement route. However, the slant column density are retrieved instead of vertical column density recently, which results in emission flux computing error. Combined with the MAX-DOAS, a mobile multi light DOAS system, which set two different elevation angle telescopes(90, 30) to receive the scattered light respectively in the mobile platform, was deployed. The slant column density in the two different viewing directions were detected, and combined with the air mass factor computing from radiative transfer model, the vertical column density of trace gas was obtained. Comparison of the current mobile single light (zenith direction) DOAS system, the mobile multi light DOAS system have a lot of advantages like high sensitivity, low uncertainty etc. A test experiment was performed in a power plant of Huainan, Anhui using the new technique. The distribution information of NO2 vertical column density along the route was derived and compared with the slant column density calculating from the zenith direction, a good agreement was found in the column density trends.

Using area-average sensible heat fluxes measured with the large aperture scintillometer(LAS), in addition to the net radiation obtained with net radiometers, the latent and soil heat fluxes can be calculated with energy balance equations. Field tests showed there was a good agreement between sensible heat fluxes obtained from an LAS and an EC system. The correlation coefficient was better than 0.8 for daytime in plant canopies. The sensible heat decreased, whereas the evaporation on the surface of the canopy attained its maximum at midday. For applications in which accuracy and area-average are of critical importance for agricultural meteorology, the LAS would be a better choice.

Ethanol is a relatively complex molecule which presents broadband absorption spectra at atmospheric pressure,its stretching overtones of OH bond is around 70007300 cm-1. The absorption spectrum of ethanol vapor with small amount of water vapor near 7180 cm-1 was acquired by adopting tunable diode laser absorption spectroscopy (TDLAS) method, an absorption feature with HWHH of approximately 1.3 cm-1 was obtained by eliminating the interference of water vapor with polynomial fitting. Study on the line-types of absorption spectra of ethanol vapor with different concentrations demonstrates that line-types have no dependence on partial pressure. This work laid the foundation for the research of ethanol remote sensing based on TDLAS.

The principles of three common measuring methods of the water turbidity, scattering method, transmission method and ratio method are introduced. Combined with pulse width modulation (PWM) and demodulation technique, the method for turbidity measurement using light intensity modulation is proposed and the experimental system and the realizing circuit of modulation and demodulation is described in detail. The experimental system is used to measure the turbidity of Formazine standard solution of different turbidity values. The measured data is listed, then the turbidity values fitting curve using the three methods are drawn. Through the analysis and comparison of the experimental results, it’s showed that when using the ratio method combined with the modulation technique, the interference of background light can be eliminated effectively, so the measuring range of the water turbidity can be improved with high measuring accuracy.

As the intrinsic parameter of fluorescence signal, the accurate measurement of fluorescence lifetime is very important to fluorescence detecting and analyzing technique. According to the characteristics of fluorescence signal and definition of fluorescence lifetime, principle of phase-locking detection technique of fluorescence lifetime is introduced. Based on phase locked loop circuit, fluorescence lifetime detecting system is designed, which is used to dissolved oxygen detecting with fluorescence method. The experimental results showed that the relative error of measured values and actual values is less than 1.5%, and the response time is less than 60 s.

There are several methods to measure the cloud height, and real-time measurement based on laser technology is the direction of future development. The prototypes or primary products of laser ceilometer are developed at home and abroad. According to the requirement of use, the laser ceilometer should work automatically and continuously in the wild, but the current products still need to be optimized and improved in the adaptation to the environment, job stability, automation, data reliability, size, energy consumption, cost and many other issues. As the core technology unit, laser ceilometer controller is dereloped, so that overall properties are improved. The structure and preliminary technical parameters of the laser ceilomter controller are given, and its data acquisition and processing, display, storage, work process and the software are briefly introduced.