Atmospheric and oceanic optics|22 Article(s)
Real-time measurement of atmospheric parameters for the 127-element adaptive optics system of 1.8-m telescope
Jie Mu, Wenjia Zheng, Mei Li, and Changhui Rao
A real-time method for measuring atmospheric parameters based on co-processor field-programmable gate array (FPGA) and main processor digital signal processing (DSP) is proposed for ground-based telescopes with adaptive optics (AO) systems. Coherence length, outer scale, average wind speed, and coherence time are estimated according to closed-loop data on the residual slopes and the corrected voltages of AO systems. This letter introduces the principle and architecture design of the proposed method, which is successfully applied in the 127-element AO system of the 1.8-m telescope of Yunnan Astronomical Observatory. The method enables real-time atmospheric observations with the same object and path of the AO system. This method is also applicable to extended objects.
Chinese Optics Letters
  • Publication Date: Sep. 14, 2012
  • Vol.10 Issue, 12 120101 (2012)
Advantages of solitonic shape pulses for full-optical wireless communication links
Jose Maria, Antonio Jurado-Navas¤, Miguel Castillo-Vazquez, Ana Belen, and Antonio Puerta-Notario
Chinese Optics Letters
  • Publication Date: Dec. 28, 2011
  • Vol.10 Issue, 4 040101 (2012)
Detection of chemical warfare agents based on quantum cascade laser cavity ring-down spectroscopy
Zhechao Qu, Chunming Gao, Yanling Han, Xiaosong Du, and Bincheng Li
Chinese Optics Letters
  • Publication Date: Jan. 17, 2012
  • Vol.10 Issue, 5 050102 (2012)
Lidar ratio of Asian haze and pollution episodes observed by using a Raman/elastic lidar
Zhenyi Chen, Wenqing Liu, Yujun Zhang, and Birgit Heese
A combined Raman/elastic backscatter lidar observations is carried out in the Pearl River Delta (PRD) China. The results show the largest lidar ratios of the order of 80 sr in the uplifting boundary layer in 2-3 km during the haze period. In the moderate pollution period, the lidar ratio has an average value of 58 sr. The Angstrom exponent exhibits high values around 1.82, indicating the presence of rather small particles. Different back air mass trajectories and the ambient atmospheric conditions are attributed to the distinct characteristics of aerosol optical properties in the haze and moderate pollution episodes. In the lower layer in the haze period, air masses are mostly advected from southeast coast China. In contrast, the air mass in the moderate pollution observing period passes through northwest China, indicating the combination of some pollution from the Tarim Basin in case of strong convection and the smoke from adjacent fire burning spot in PRD region.
Chinese Optics Letters
  • Publication Date: Apr. 25, 2012
  • Vol.10 Issue, s1 S10101 (2012)
Analysis and demonstration of PID algorithm based on arranging the transient process for adaptive optics
Zhaoying Zheng, Changwei Li, Bangming Li, and Sijiong Zhang
Chinese Optics Letters
  • Publication Date: Oct. 31, 2013
  • Vol.11 Issue, 11 110101 (2013)
Measuring atmospheric turbulence strength based on differential imaging of light column
Honghua Huang, Chaolong Cui, Wenyue Zhu, Zaihong Hou, Yi Wu, and Ruizhong Rao
Chinese Optics Letters
  • Publication Date: Dec. 09, 2013
  • Vol.11 Issue, 12 120101 (2013)
Fourier–Mellin expansion coefficients of scaled pupils
Barmak Honarvar, and Raveendran Paramesran
Chinese Optics Letters
  • Publication Date: Jul. 26, 2013
  • Vol.11 Issue, 8 080101 (2013)
Numerical simulation and analysis of dynamic compensation for atmosphere turbulence based on stochastic parallel gradient descent optimization
Huimin Ma, Pengfei Zhang, Jinghui Zhang, Chunhong Qiao, and Chengyu Fan
We present the numerical simulation and analysis of the bandwidth estimation for adaptive optics (AO) systems based on stochastic parallel gradient descent (SPGD) optimization. Time-varying atmosphere turbulence due to wind velocity and turbulence structure constant is considered in the dynamic simulation. The performance of SPGD system with different iteration frequencies is studied in detail. A formula given that estimates the Strehl ratio degradation after SPGD adaptive control due to the increasing proportion of the number of deformable mirror actuator times Greenwood frequency to iteration frequency based on numerical analyses, can be used to roughly predict the required iteration frequency under the condition of various Greenwood frequencies.
Chinese Optics Letters
  • Publication Date: May. 09, 2012
  • Vol.10 Issue, s1 S10102 (2012)