自由空间激光通信APT(Acquisition,Pointing and Tracking)系统主要由粗跟踪系统和精跟踪系统组成,粗跟踪系统主要是完成对目标信号的捕获,以确保入射的信标光在精跟踪控制系统的动态范围内。介绍了粒子滤波在APT粗跟踪系统中的应用,针...自由空间激光通信APT(Acquisition,Pointing and Tracking)系统主要由粗跟踪系统和精跟踪系统组成,粗跟踪系统主要是完成对目标信号的捕获,以确保入射的信标光在精跟踪控制系统的动态范围内。介绍了粒子滤波在APT粗跟踪系统中的应用,针对粒子滤波在跟踪算法中存在的问题进行了改进,设计了颜色和轮廓双重信息融合的似然模型;为提高目标跟踪算法在异常情况下的有效性,采用了异常检测和恢复策略,并设计了跟踪光斑目标的模拟系统。实验表明:所提出的多信息融合的似然模型跟踪算法在目标尺度变化、背景干扰、姿态变化、部分遮挡等环境下均能稳定地跟踪目标,提高了大气激光通信链路的可靠性。展开更多
A free-space communication based on a mid-infrared quantum cascade laser （QCL） is presented. A room-temperature continuous-wave distributed-feedback （DFB） QCL combined with a mid-infrared detector com- prise the b...A free-space communication based on a mid-infrared quantum cascade laser （QCL） is presented. A room-temperature continuous-wave distributed-feedback （DFB） QCL combined with a mid-infrared detector com- prise the basic unit of the communication system. Sinusoidal signals at a highest frequency of 40 MHz and modu- lated video signals with a carrier frequency of 30 MHz were successfully transmitted with this experimental setup. Our research has provided a proof-of-concept demonstration of space optical communication application with QCL. The highest operation frequency of our setup was determined by the circuit-limited modulation bandwidth. A high performance communication system can be obtained with improved modulation circuit system.展开更多
The possibility of visible red light laser being used as signal light source for Free-Space Optical (FSO) communication is proposed. Based on analysis of transmission in atmospheric channel concerning 650 nm laser bea...The possibility of visible red light laser being used as signal light source for Free-Space Optical (FSO) communication is proposed. Based on analysis of transmission in atmospheric channel concerning 650 nm laser beam, performance of wireless laser communication link utilizing a low power red laser diode was evaluated. The proposed system can achieve a maximum range of 300 m at data rate 100 Mb/s theoretically. An experimental short-range link at data rate 10 Mb/s covering 300 m has been implemented in our university. It is feasible to enhance the system performance such as link range and data rate by increasing transmitting power and decreasing laser beam divergence angle or through other approaches.展开更多
文摘自由空间激光通信APT(Acquisition,Pointing and Tracking)系统主要由粗跟踪系统和精跟踪系统组成,粗跟踪系统主要是完成对目标信号的捕获,以确保入射的信标光在精跟踪控制系统的动态范围内。介绍了粒子滤波在APT粗跟踪系统中的应用,针对粒子滤波在跟踪算法中存在的问题进行了改进,设计了颜色和轮廓双重信息融合的似然模型;为提高目标跟踪算法在异常情况下的有效性,采用了异常检测和恢复策略,并设计了跟踪光斑目标的模拟系统。实验表明:所提出的多信息融合的似然模型跟踪算法在目标尺度变化、背景干扰、姿态变化、部分遮挡等环境下均能稳定地跟踪目标,提高了大气激光通信链路的可靠性。
基金Project supported by the State Key Development Program for Basic Research of China(Nos.2013CB632801,2013CB632803)the National Natural Science Foundation of China(Nos.61435014,61306058,61274094)
文摘A free-space communication based on a mid-infrared quantum cascade laser （QCL） is presented. A room-temperature continuous-wave distributed-feedback （DFB） QCL combined with a mid-infrared detector com- prise the basic unit of the communication system. Sinusoidal signals at a highest frequency of 40 MHz and modu- lated video signals with a carrier frequency of 30 MHz were successfully transmitted with this experimental setup. Our research has provided a proof-of-concept demonstration of space optical communication application with QCL. The highest operation frequency of our setup was determined by the circuit-limited modulation bandwidth. A high performance communication system can be obtained with improved modulation circuit system.
文摘The possibility of visible red light laser being used as signal light source for Free-Space Optical (FSO) communication is proposed. Based on analysis of transmission in atmospheric channel concerning 650 nm laser beam, performance of wireless laser communication link utilizing a low power red laser diode was evaluated. The proposed system can achieve a maximum range of 300 m at data rate 100 Mb/s theoretically. An experimental short-range link at data rate 10 Mb/s covering 300 m has been implemented in our university. It is feasible to enhance the system performance such as link range and data rate by increasing transmitting power and decreasing laser beam divergence angle or through other approaches.
