To improve the performance of composite pseudo-noise （PN） code clock recovery in a regenerative PN ranging system at a low symbol signal-to-noise ratio （SNR）, a novel chip tracking loop （CTL） used for regenerati...To improve the performance of composite pseudo-noise （PN） code clock recovery in a regenerative PN ranging system at a low symbol signal-to-noise ratio （SNR）, a novel chip tracking loop （CTL） used for regenerative PN ranging clock recovery is adopted. The CTL is a modified data transition tracking loop （DTTL）. The difference between them is that the Q channel output of the CTL is directly multiplied by a clock component, while that of the DTTL is multiplied by the Ⅰ channel transition detector output. Under the condition of a quasi-squareware PN ranging code, the tracking （ mean square timing jitter） performance of the CTL is analyzed. The tracking performances of the CTL and the DTTL, are compared over a wide range of symbol SNRs. The result shows that the CTL and the DTTL have the same performance at a large symbol SNR, while at a low symbol SNR, the former offers a noticeable enhancement.展开更多
Aim To develop a high speed and high resolution dynamic rangefinding device for the measurement of large distances.Methods The device was comprised of an ultrasonic transmitter and a receiver,and a receiver , and a co...Aim To develop a high speed and high resolution dynamic rangefinding device for the measurement of large distances.Methods The device was comprised of an ultrasonic transmitter and a receiver,and a receiver , and a continuous ultrasonic wave amplitude-modulated by a low- frequency acoustic signal was used. The rangefinding was achieved by detecting the phase difference between the transmitted and received ultrasonic signals. The design principle. hard- ware implementation , experimental results and performance analysis of the device are included. Results and Conclusion Experiments show that the accuracy of the device are included. within 1.5m while its dynamic data update rate can be up to 40kHz.展开更多
P225.2 98053048光电跟踪测距中的测量检测技术=Metering andtesting technique in the photoelectrical track—ing rangefinders[刊,中]/汤正兴(电子部第27研究所。河南,郑州(450052))∥电光系统。—1997,(3)。—31—35介绍了利用半...P225.2 98053048光电跟踪测距中的测量检测技术=Metering andtesting technique in the photoelectrical track—ing rangefinders[刊,中]/汤正兴(电子部第27研究所。河南,郑州(450052))∥电光系统。—1997,(3)。—31—35介绍了利用半导体光源可达秒级的激光跟踪误差斜率曲线测量系统。阵列式激光光束光强分布测试仪和激光跟踪测距接收机数据采集与处理的接口和打印、I/O接口等。成为激光跟踪测量工程任务设备装配检验和测量的依托手段,给出误差斜率曲线的测试结果。图11参2(金友)展开更多
文摘To improve the performance of composite pseudo-noise （PN） code clock recovery in a regenerative PN ranging system at a low symbol signal-to-noise ratio （SNR）, a novel chip tracking loop （CTL） used for regenerative PN ranging clock recovery is adopted. The CTL is a modified data transition tracking loop （DTTL）. The difference between them is that the Q channel output of the CTL is directly multiplied by a clock component, while that of the DTTL is multiplied by the Ⅰ channel transition detector output. Under the condition of a quasi-squareware PN ranging code, the tracking （ mean square timing jitter） performance of the CTL is analyzed. The tracking performances of the CTL and the DTTL, are compared over a wide range of symbol SNRs. The result shows that the CTL and the DTTL have the same performance at a large symbol SNR, while at a low symbol SNR, the former offers a noticeable enhancement.
文摘Aim To develop a high speed and high resolution dynamic rangefinding device for the measurement of large distances.Methods The device was comprised of an ultrasonic transmitter and a receiver,and a receiver , and a continuous ultrasonic wave amplitude-modulated by a low- frequency acoustic signal was used. The rangefinding was achieved by detecting the phase difference between the transmitted and received ultrasonic signals. The design principle. hard- ware implementation , experimental results and performance analysis of the device are included. Results and Conclusion Experiments show that the accuracy of the device are included. within 1.5m while its dynamic data update rate can be up to 40kHz.
文摘P225.2 98053048光电跟踪测距中的测量检测技术=Metering andtesting technique in the photoelectrical track—ing rangefinders[刊,中]/汤正兴(电子部第27研究所。河南,郑州(450052))∥电光系统。—1997,(3)。—31—35介绍了利用半导体光源可达秒级的激光跟踪误差斜率曲线测量系统。阵列式激光光束光强分布测试仪和激光跟踪测距接收机数据采集与处理的接口和打印、I/O接口等。成为激光跟踪测量工程任务设备装配检验和测量的依托手段,给出误差斜率曲线的测试结果。图11参2(金友)
