In order to study the changes of the atmospheric boundary layer’s structure in Hefei, the polarization-Raman-Mie scattering lidar system is operated automatically and continuously. The gradient method used to extract the height of atmospheric boundary layer from lidar data is introduced and analyzed. The modified gradient method is used to obtain the temporal characteristics of the height of atmospheric boundary layer in Hefei. The results show that the height of atmospheric boundary layer in Hefei ranges from 1 km to 1.5 km, and the average height is about (1.28±0.2) km during the experiment.

Doppler lidar plays an important role in wind measurements and numerical weather prediction, and signal to noise ratio (SNR) is an important parameter to measure the system’s accuracy. Based on the first mobile Doppler lidar system in China which is developed by Ocean University of China in 2007, the SNR for sea surface wind measurements with four different repetition rates are simulated. Simulated and measured data are in good agreement. The results show that the lower laser frequency used in the lidar, the higher SNR obtained. According to the requirements for operational measurements, Doppler lidar requires relatively high laser repetition rate. It is recommended to select a laser with pulse repetition rate during 500～1000 Hz.

An inverse method is introduced to derive aerosol optical properties by using direct solar radiation and sky scattering radiation. Based on the method, aerosol optical properties including aerosol optical depth, Angstrom exponent, single scattering albedo, scattering phase function and polarized phase function are retrieved from measured data by the sun photometer. A useful method is provided to acquire single scattering albedo, scattering phase function and polarized phase function of aerosol for application on remote sensing.

Based on the size distribution of atmospheric aerosols, the scattering characteristics of aerosols at visible and infrared wave band are calculated by Mie scattering theory, the effects of aerosols on the laser transmission attenuation at visible and infrared wave band are discussed. The numerical simulation results show that the scattering characteristics of aerosols are sensitive to the types and size distributions of aerosols; the laser transmission attenuation are affected not only by the refractive index and types, but also by number density of aerosols. The more the number density, the stronger the laser transmission attenuation will be; while the asymmetry parameter is insensitive to the number density, which is mainly influenced by the size distribution. These results are beneficial to evaluate the effect of aerosols on laser transmission, which will promote the application of laser signal transmission, communication and wind measurement by laser.

A set of gas sensor based on quantum cascade laser (QCL) for ambient nitrous oxide (N2 O) monitoring is introduced. QCL is utilized in the center wavelength of 1274 cm-1, combining with multi-pass absorption cell. By taking the advantages of long pulsed QCL which produces a complete scan of molecular absorption lines of gases, high sensitive measurement of N2 O can be realized. Integrated software provides data analysis according to HITRAN04 database, without calibration gas. A detection limit of 13 ppb is obtained by analyzing the standard deviation and the detection of N2 O in the atmosphere is realized.

The aerosol is one of the major pollutant components in the atmosphere. And the aerosol has a significant impact in the process of air pollution. The component and distribution of inorganic ions detected by FTIR show that the ambient aerosols source is related to the diameters of aerosols in Hefei. In winter, when the diameters of aerosols are smaller than 2.5 μm, the human activity is the main source, such as waste dumping, landfills and the exhaust gas from the vehicle. When the diameters are larger than 2.5 μm, the ore is the main source.

According to cloud particle depolarization theory of polarization lidar, and based on the relationships between layer-integrated attenuated backscatter(β) and layer-integrated depolarization ratio (δ) of a two dimensional threshold and their spatial coherence analysis technique, a cloud phase discrimination algorithm using CALIPSO data was established. The testing retrieval sample of CALIPSO data of China region on March 3, 2010 used for the new algorithm were mainly derived from CALIPSO cloud phase product. The results show the new cloud phase discrimination algorithm based on CALIIPSO data has superior accuracy.

The network control system for atmospheric detection equipments consisted of the master control computer, the control machines to the atmospheric detection equipments and the network switch. This system applied Windows Socket to achieve the communication and selected the asynchronous communication mechanism to avoid the occurrence of the block. The message package format was designed in detail aimed at the specific requirements of this system and XML was employed to unify the various formats of the data measured in each control machine. Finally this system achieved the centralized control of the atmospheric detection equipments and the centralized access to a variety of atmospheric parameters.

The design of multi-axis differential optical absorption spectroscopy(MAX-DOAS) control system based on AVR MCU was introduced. The control system realized data communication, background motor control, scanning motor control and temperature detection and control. Both hardware and software design of the whole control system were described. The design of the control system can make the MAX-DOAS analyzer realize automatic monitoring of trace gases vertical column concentration and profile.

Design of driving schedule is important for CCD to perform well. A driving schedule design based on FPGA (field programmable gate array) is put forward for the scientific grade CCD47-20 BI AIMO (advanced inverted mode operation) of e2v Company. This design is developed on the FPGA-APA600 hardware platform using Verilog language in LiberoIDE v9.0 development environment, and simulated in ModelSim6.0. Image acquisition experiments were implemented with the image collection card of Matrox Company. The experiment indicated that the CCD performed stably, and the design met the driving requirements of CCD47-20 BI AIMO. The result has been applied to CCD readout circuit of spatial heterodyne interferometer for oxygen detection with good performance.

In order to avoid adverse vibration influence on mobile Doppler wind lidar when it is moving and ensure measurement’s stability and accuracy, a vibration isolation system is designed for cabinets and optical table of mobile wind lidar. SB and M series wire rope isolators of IDC company are respectively selected as the isolators of cabinets and optical table. By calculating, the peak response frequency is less than disturbing frequency and shock displacement is less than the max deflection of the isolators. The relation graph between vibration isolation efficiency and disturbing frequency illustrates that the vibration isolation efficiency is more than 80%. Finally, comparing the locking frequency effect in the same vibration environment before and after vibration isolation system installed, it is obvious that the vibration isolation system improves the frequency stability. It is further certified the reliability of isolation by sine curve fitting of light of sight (LOS) velocity at the elevation of 1 km during moving measurements.

Optical system design of multispectral camera based on liquid crystal tunable filter(LCTF) was presented. The optical system has a focal length of 60 mm, F number is 3.5, spectrum band is 400～720 nm, and the field angle is 16.6°. It consisted of the fore-optical system and the subsequent imaging system, the fore-optical system was adopted in order to attain beam of light which can fulfill requirement of the aperture and field angle of LCTF, the double Gaussian structure was adopted in the subsequent imaging system. The imaging analysis results show that the design fulfills operating and engineering requirement. The optical system can produce a clear image in 16 waveband of the spectral range.