差分吸收激光雷达系统性能分析及信息处理系统仿真研究

【作者】 李新山；

【导师】 王蔚然；

【作者基本信息】 电子科技大学 ， 通信与信息系统， 2003， 硕士

【摘要】 基于二氧化碳激光器的差分吸收激光雷达（CO2 DIAL）系统被广泛地应用于对大气分子种类以及微量气体进行遥感的测量之中，具有非常重要的军事和民用价值。为研制出有实用价值的DIAL系统，本文在参考大量国内外文献的基础上，对系统原理以及影响系统测量精度和灵敏度的各种因素进行了详细讨论，并且着重分析了大气湍流和目标斑纹这两个最重要因素对高脉冲能量的CO2 DIAL系统测量灵敏度的影响。在课题实验条件下，模拟计算了直接检测DIAL系统的测量灵敏度。在考虑大气折射率结构常数对系统测量灵敏度影响的基础上，并对各种系统参数如光束半径、束散角和探测距离对测量灵敏度的影响运用Matlab程序做了仿真计算，为合理选择系统设计参数提供了依据。对于DIAL系统中的数据处理，本文着重讨论了信号平均技术和激光器回波信号时域自相关以及激光器互相关对CO2 DIAL系统测量灵敏度的影响。运用信号平均技术之后，本课题研制的系统其测量灵敏度完全可以满足设计要求。此外，本文还专门进行了DIAL系统中信号处理部分的仿真研究，证实了系统数据处理的可行性。由于项目开发处于初期，本文的很多结论都是建立在国外有关文献实验数据资料的基础上，只是在理论上进行了切实的研究。更多还原

【Abstract】 CO2 laser-based differential absorption lidar(DIAL) systems have been used extensively for the remote sensing measurement of molecular species in the atmosphere and trace gases, therefore, have important value in military and civilian fields.For the needs of researching a useful DIAL system, in this thesis, we studied a vast Chinese and English literature and discussed the principle of DIAL system in detail. We analyzed the factor of influencing the accuracy and sensitivity of measurements, in special, discussed the influence of atmospheric turbulence and laser speckle. Under our task experimental condition, we calculated the sensitivity of our planning to develop DIAL system with direct detection, besides, we studied the relationship between the sensitivity of measurement and atmospheric refractive-index structure constant and applied Matlab program simulated the system parameters such as beam diameter, laser divergence angle, detection distance and gained relevant relationship curves. It is useful for selecting reasonable system parameters through it.For the data process in DIAL system, we discussed the combined effects of temporal autocorrelation and lasers cross correlation and signal averaging. If signal averaging technology was used in our CO2 DIAL system, then would improved the sensitivity of measurement clearly and could meet the demand of development. Moreover, this thesis simulate the part of signal processing in DIAL system and validate the feasibility of our signal processing methods.Because all of this research began in the front of task, the results just based on the experimental data of abroad literature, so, this is a theoretically research.更多还原