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题名	星载激光雷达高速数据采集系统
作者	林明杰
学位类别	硕士
答辩日期	2014
授予单位	中国科学院上海光学精密机械研究所
导师	侯霞
关键词	激光雷达 高速数据采集 信号处理 高动态范围
其他题名	Data Acquisition System Design in Spaceborne Lidar
中文摘要	星载激光雷达在探测全球风场、气溶胶、云层和CO2浓度分布等众多大气参数，以及地形、地貌测量等有重要应用。激光雷达探测所获取的原始信息来源于激光回波信号，数据采集处理系统主要实现对其进行高带宽的全波形数字采样，是激光雷达的重要组成部分。只要在适当的时候将发射的光信号的回波的波形完整的采集下来，对回波信号加以分析，就可以通过反演获得链路中大气的信息，获得距离等其它信息。 本论文主要研究内容是星载激光雷达中的数据采集系统的数据采集的软硬件系统设计和测试工作。 星载激光雷达回波信号具有动态范围较大，信号为窄脉冲形式的特殊性，对其进行全波形的数据采集，其中涉及的关键技术有高速数据采集技术、大动态范围采样技术及高精度采样技术等。通过文献调研，以及对雷达回波信号的定性的分析，作为大气探测雷达，数据采集系统的动态范围至少要达到130 dB，在此基础上尽可能提高采样率。为此从两个方面开展数据采集系统的研制，一是高精度、高动态范围、采样率在百MSPS的系统；二是高速采样，采样率在GSPS，通过通道复用的方式提高系统采样率。 通过对现有的数据采集系统的技术调研，针对高精度、大动态范围的采样要求提出了双通道拼接的技术方案，以实现130dB的动态范围的信号采集。针对高速信号的采集与处理方面，提出了通过扩展总线以及采用双数据沿采样的方式，采样数据的传输速率降低到采样时钟的1/4，实现单通道1GSPS的采样速率。并进行了双通道复用的设计，为日后进行扩展打下基础。 据此研制了以FPGA为处理核心的高速硬件电路。经过测试，所研制的高精度数据采集系统：采样率100 MHz、有效位达到11位、动态范围达到22位，信噪比大于66 dB；高速数据采集系统：采样速率可以达到1 GHz，并且通过两个通道的复用技术，最高单通道的采样速率最高可以达到2 GHz，实际测试采样结果的有效位达到7.5位，信噪比达到49 dB，模拟信号的输入带宽高于240 MHz。 通过对已完成的数据采集系统的测试验证，完成了高速数据采集系统中涉及的关键技术攻关，所完成的系统样机可以用于星载激光雷达的回波信号采集。
英文摘要	Spaceborne lidar plays an important role in measurement of global wind, aerosols, clouds and CO2 concentration distribution and so on, as well as in topographic mapping. As a large amount of data is stored in the signals, a high-speed data acquisition system, which can acquire and analyze the echo signals, is crucially important for a spaceborne lidar. the data acquisition system is an important part in the lidar, which can acquire and analyze these echo signals. As long as the echo signal is acquired and stored completely, lots of information such as the distance can be deduced from the collected signal. In this thesis, the data acquisition system in spaceborne lidar is studied. As the echo signal of lidar is always high dynamic and pulsed, a specific system is designed and used to acquire high speed and high dynamic range signal.Throughresearch and the qualitative analysis of lidar echo signals,it is concluded that the dynamic range needs to be greater than 130 dB for the data acquisition system in an atmospheric lidar,and the sample rate needs to be as high as possible.Therefore,two types of system are developed based on these demands.One is a high dynamic range and high precision data acquisition system, and the other is a high speed data acquisition system. Through researches on existing data acquisition systems, the dual-channel stitching technique is adopted, and the sample rate achieves 2 GSPS under this condition. Dual-channel stitching technology is also used in high dynamic range data acquisition system, which lead the dynamic range upto 130 dB, For high-speed data transmission, double-rate-data technology and data bus expansion technology are used, the transmission rate of sample data is decreased to a quarter of sample clock. Based on FPGA, two sets of hardware circuit are developed for the two types of data acquisition systems, respectively. Experimental results show that, the effective number of bits reaches 11,signal to noise ratio over 66 dB, and the dynamic range reaches 22 bit, under a sample rate of 100 MHz; for in high speed data acquisition system, the sample rate reaches 1 GHz in dual channel mode, and 2 GHz in signal channel mode, the effective number of bit reaches 7.5, signal to noise ratio reaches 49 dB, and bandwidth greater than 240 MHz. Through the systematic design and testing experiments, the data acquisition system of lidar is analyze in details, and corresponding technical difficulties are solved. One data acquisition system with high dynamic range and high accuracy and one with high speed are designed. The designed prototypes can be applied to data acquisition in spaceborne lidar system.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/16876]
专题	上海光学精密机械研究所_学位论文
推荐引用方式 GB/T 7714	林明杰. 星载激光雷达高速数据采集系统[D]. 中国科学院上海光学精密机械研究所. 2014.

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