Invited column-Laser fuze technology

Review on coherent laser fuze(Invited)
Liu Ximin, Zhang Jianhua, Yang Dezhao, Zhang Mingyi
2018, 47(3): 303001. doi: 10.3788/IRLA201847.0303001
[Abstract](689) [PDF 957KB](175)
With the advantages of high sensitivity and carrying rich information, laser coherent detection technology has been used widely in military, mapping, communications and other fields. Coherent detection is developing rapidly in laser radar and laser communication applications, but it has not been carried out on a large scale in laser fuze. With coherent detection applied to laser fuze, the speed of targets can be obtained by detecting the laser Doppler signals, and the anti-interference ability of natural environment can be improved greatly by using the velocity difference between the target and the interference. A brief introduction of the principle and the characteristics of coherent detection was given, and then four kinds of coherent laser fuze system, the principle and system composition of a typical linear frequency modulation coherent laser fuze were discussed in detail. At present, coherent laser fuze was still in its infancy, which enhanced the system capabilities obviously and had a broad application prospects, and it deserved further study by relevant research institutes for expediting the engineering application process of coherent laser fuze.
Laser gray imaging fuze technology for air-to-air missile
Wang Xiaoju, Ma Heng, Zhang Shunfa
2018, 47(3): 303002. doi: 10.3788/IRLA201847.0303002
[Abstract](589) [PDF 1565KB](130)
Aiming at the problem that air to air missile laser fuse is easily interfered by cloud, smoke and ground sea clutter, a laser gray imaging fuze technology for air to air missile was proposed. The push broom linear array detection method was used, which was progressive scanning gray imaging with the intersection motion of missile and target according to amplitude information of laser echo. The progressive target recognition algorithm was used to deal with the gray outline image accumulated by line to realize the precise detection of laser fuze, so its anti-interference ability can be improved. The test results of the prototype show that the scheme of the laser gray imaging fuze technology is feasible, the hardware realizability is high, and the image data obtained from the test can provide technical reserve for anti-jamming research of laser fuze.
Design of fuze-warhead coordination based on laser fuze and prefabricated fragment ammunition
Yu Yuting, Shu Jingrong, Ding Bosheng
2018, 47(3): 303003. doi: 10.3788/IRLA201847.0303003
[Abstract](713) [PDF 1034KB](119)
Aiming at the fragmentation dispersion characteristic of prefabricated fragment ammunition, fuze-warhead coordination was designed based on prefabricated fragment ammunition controlled by laser proximity fuze. Ideal warhead explosion height was obtained through formula deduction, Matlab software simulation and calculation of target damage at a equivalent area. Under this condition of the ideal explosion height, the laser fuze was designed through selecting appropriate laser beam detection field. Thus a optimal design of fuze-warhead coordination under specified conditions was completed. Results showed that:in the the range of 5 m of the missile dispersion, 60 pitch angle and 5 m3 m3 m command vehicle target, effective fragment density is the biggest at the warhead explosion 4-6 m height. Detection probability and height of the laser proximity fuze are analyzed and calculated at the height interval of the detonating height, the optimal beam emission angle of laser fuze is from 17 to 30. This design is of practical reference value for the application of the prefabricated fragment ammunition controlled by laser fuze.
Feature extraction methods and applications of signal feature for pulse laser fuze(Invited)
Cai Kerong, Qiu Likuan, Gao Ruilin
2018, 47(3): 303004. doi: 10.3788/IRLA201847.0303004
[Abstract](586) [PDF 940KB](127)
The laser fuze has advantages of strong anti-electromagnetic interference, high fixed angle and ranging precision, and small size. However, laser fuze's application isn't wide in air defense missiles because of the high false alarm rate. By analyzing the levels of signal feature extraction methods, the contributions of laser echo signal's features to anti-jamming performance and coordinated efficiency of fuze and warhead were discussed, including its energy, delay, pulse width, and information fusion. Then, based on an air defense missile's panoramic laser fuze, the target recognition algorithm was designed using linear array detector. The reliability of target detection is improved obviously, while the visibility of smoke coming down to 110 m, the laser fuze can still detect target exactly.
Analysis and evaluation of detection distance effect on detection capability of laser fixed-distance fuze
Yao Zongchen, Zhang He, Zhang Xiangjin, Huang Zhengxiang, Yue Lianyong
2018, 47(3): 303005. doi: 10.3788/IRLA201847.0303005
[Abstract](530) [PDF 1250KB](91)
To comprehensively evaluate the detection capability of the laser fixed-distance fuze, and obtain the variation in detection capability with the detection distance, the analytic equation of the distribution of pulsed laser ranging was established by deriving the echo equation of pulsed laser ranging, and an error quantification evaluation method was also proposed. The influence of detection distance on echo signal and the indicators of detection capability were analyzed and evaluated, and the results were verified by experiments. Results indicate that the detection of fuze is reliable within its reliable range. In addition, the random ranging error tends to initially decreases and then increases while the system error has the trend to increase gradually as the detection distance decrease. The maximum reliable range of fuze is 84.8 m and the random error is 0.22-0.73 m in the reliable range, thus satisfying the requirement of remote fixed-distance fuze. Besides, with the increase of the threshold, the range error can be obviously improved a lot, although the reliable range is caused to be reduced. The variation rules and evaluation methods in this work can provide a theoretical basis for the design and application of the pulsed laser fuze.