机载蓝绿激光雷达水深信息获取与处理方法

发布时间：2018-06-04 00:15

本文选题：微波调幅激光雷达 + 海水后向散射　；参考：《大连海事大学》2016年硕士论文

【摘要】：机载蓝绿激光雷达不仅可以进行航道测量、海底测绘、探测水下目标(如水雷、鱼群等),而且测量效率高,运行成本低,是一种极具前景的水下探测手段。国外对机载蓝绿激光雷达的研究相对较早,如今已经研制出蓝绿激光雷达水下探测系统,但是存在精度低,误差大、目标信号难以识别等问题。我国对机载蓝绿激光雷达的研究起步晚于西方,如今还处于实验室研究和分析阶段。机载蓝绿激光水下测量系统研究难度在于如何减弱海水吸收及散射特性对目标信号产生的影响。海水的吸收特性会造成激光脉冲信号严重衰减,而海水的散射特性会产生后向散射噪声,而且海水后向散射产生的噪声不仅能量高,而且动态范围大,很容易淹没目标信号,使目标探测的难度加大。海水对光的吸收导致接收信号减弱的问题可以通过提高发射功率来解决,但是当发射功率增大时,不仅目标信号增强了,海水产生的后向散射信号同时也增强了,所以如何减小海水的后向散射噪声对目标信号的影响成为本文的研究重点。针对海水后向散射问题,本文引入了基于微波技术的激光雷达水深信号处理技术来减弱海水后向散射噪声对目标信号的影响,其基本原理是在发射端,通过调幅方式使蓝绿激光携带微波信息,然后蓝绿激光携带着微波信息在水中传输,到达水底返回被接收器接收,通过调制解调技术获得携带着目标信息和后向散射信息的微波信号,然后利用成熟的微波信号处理技术对目标信号进行相关处理,从而到达抑制海水后向散射信号,提高信号对比度,获得水深信号的目的。最后本文通过仿真实验验证了该技术的有效性。
[Abstract]:Airborne blue green laser radar can not only carry out channel measurement, seabed surveying and mapping, detect underwater targets (such as mines, fish and so on), but also have high measurement efficiency and low operating cost. It is a very promising underwater detection method. The study of airborne blue green laser radar is relatively early. Now the blue green laser radar is developed. However, there are many problems, such as low precision, large error, and difficult identification of target signals. The study of airborne blue green laser radar in China is later than in the west, and it is still in the stage of laboratory research and analysis. The difficulty in the study of airborne blue green laser underwater measurement system is how to weaken the effect of the absorption and scattering characteristics of sea water on the target signal. The absorption characteristics of the sea water will cause serious attenuation of the laser pulse signal, and the scattering characteristics of the sea water will produce backscattering noise, and the noise produced by the backscattering of sea water is not only high in energy but also in a large dynamic range. It is easy to drown the target signal and increase the difficulty of the target detection. The absorption of the light to the sea water leads to the attenuation of the receiving signal. The problem can be solved by increasing the emission power, but when the emission power is increased, not only the target signal is enhanced, but the backscatter signal produced by the sea water is also enhanced simultaneously. So how to reduce the influence of the backscattering noise on the target signal is the focus of this paper. The laser radar water depth signal processing technology based on microwave technology is used to weaken the influence of the backscatter noise on the target signal. The basic principle is to carry the blue green laser with the microwave information at the launching end, and then the blue green laser carries the microwave information in the water and reaches the bottom and returns to the receiver. The over modulation and demodulation technology obtains the microwave signals carrying the target information and backscatter information, and then uses the mature microwave signal processing technology to deal with the target signal, thus reaching the backscatter signal to suppress the sea water and improving the signal contrast and obtaining the water depth signal. Finally, this paper has verified this by the simulation experiment. The effectiveness of technology.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P715.5

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