Design And Implementation Of A Portable Anti-Optoelectronic Detection System

In modern military warfare,anti-terrorism,security,and VIP protection,various firepower strike weapon systems,snipers,etc.will be equipped with high-performance photoelectric search and tracking systems to quickly and accurately complete the reconnaissance,tracking of targets and accurate strike.Such sophisticated weapons and equipment are highly aggressive and threaten the safety of soldiers on the battlefield and key figures in important public places.Therefore,it is a necessary defense task to curb these well-functioning weapons and find the photoelectric system installed behind the hidden objects.Nowadays,some countries have already used acoustic detection and infrared detection technology reconnaissance systems to curb the firepower of weapons and equipment,but they are all passive detection and can only be detected after the enemy has fired.In the case of an enemy’s first kill,the significance of these detection is greatly reduced.In order to minimize the effect of the enemy’s photoelectric tracking system and snipers,it is necessary to promptly,accurately and quickly discover and eliminate the "eyes" of these weapon systems,and it is urgent to conduct research on new anti-reconnaissance and anti-guidance detection system.In order to solve this problem,a portable anti-photoelectric detection system based on laser active detection technique is designed in this thesis.Mainly after the photoelectric system is irradiated by a laser,the laser beam incident to its splitter will return along the original road,and the reflection intensity is 2 to 4 orders of magnitude higher than the diffuse reflection wave,the so-called "cat eye effect".By identifying the intensity characteristics of the target echo signal,we can identify whether there are optoelectronic weapon systems and snipers and other hidden areas such as mountains,jungles,and urban buildings,detect and determine their location,and before the enemy’s optoelectronic system completes the reconnaissance mission,Guide the attack weapon to interfere or damage its optical system and sensors,and make the enemy weapon system "blind".First of all,on the basis of investigation and analysis of the current development of laser active detection technique at home and abroad,the key techniques of laser active detection and laser active detection involved in the system are described and analyzed.The laser active detection technique based on the "cat’s eye effect" was studied.Secondly,according to the requirements of the system,the overall design of the detection system integration and the active detection part is completed,and the key components of the system,the laser of the transmitting source,and the detector of the receiving end are selected.The hardware structure of the system is discussed and analyzed in detail,and the system-related laser control circuit,the laser echo collection and processing circuit based on the linear CCD,and a system control circuit based on the DSP+FPGA hardware platform are designed.The project realizes laser emission,echo reception,system control,data processing and display module,and gives the detailed circuit diagram of the corresponding circuit.The target recognition and extraction algorithm of "cat’s eye" is transplanted into DSP+FPGA based hardware platform.According to the system hardware and algorithm characteristics,a portable prototype of anti-photoelectric detection system is studied and trial-produced.Thirdly,a signal acquisition and processing algorithm based on "image difference" algorithm is proposed for the target extraction problem of "cat eye".The implementation of this algorithm combines modern control technique,PWM technique,that is,through the FPGA output modulation signal,so that the laser control circuit can drive the laser emitted by the laser to become a pulse laser with a certain period of time,thus obtaining the laser main and passive images.The detection software is designed and developed by using the method of primary and passive image difference to remove background signals,reduce noise and false alarm rate.Finally,the environmental applicability and detection effectiveness of the portable anti-photoelectric detection system based on laser active detection technique are verified by field test and experimental data analysis.It has a good performance in ensuring detection distance and low false alarm rate.