The Signal Detecting And Processing In Transmissivity Dynamic Measuring Of The Plume Penetrated By Laser

This is a key technology to measure the plumes transmittance of propellant for infrared-laser in the rocket and missile research. The magnitude of transmittance directly influences the performance and precision of laser guide. Researching the plumes transmittance characteristic of different propellant can provide the data for selecting optimal propellant prescription. We are entrusted to design a dynamic transmittance measuring system about laser plumes by an institute of CASC. The research is significant for testing technology of propellant and laser guide. According to the client's request, the paper presents a method of plumes transmittance dynamic testing with the 1064nm infrared laser permeating though plumes by researching the measurement of plume and smoke in domestic and foreign. In the testing system an infrared laser beam sent out by the 1064nm laser pass through the plume smoke produced by solid propellant burning after atmospheric transmission and arrives the receiving subsystem. The laser transmittance is obtained by measuring the power change of laser at receiving subsystem. In the paper the attenuation principle of laser crossing atmosphere and plume is analyzed and a method of testing plume transmittance of laser is presented. The paper introduces the emission optical system design with double optical path and inversion Galileo telescope, the receiving optical system with exit window detecting. The design is given about photoelectric conversion circuit with PIN and an integrated SCM system with data collection, data processing, LED display, communication and memory based on ATMEL89S51. The assembly language program for SCM system is presented. The menu for PC and Flow chart of software is submitted. Some anti-jamming instrumentality for designing circuit and making PCB is adopted to increase the reliability of electronic subsystem. Finally, the result of dynamic and static testing for system is given and analyzed. This dynamic measurement system has the characteristics of responding quickly, smaller volume, long life and strong anti-jamming ability etc. The system can make the testing of smoking box in the room and the outfield testing in the outdoor condition and has the well compatibility. The system have functions of data calibrate , real time data display, the system demarcate, the real-time dynamic drawing data curve, data storage and print etc. The measurement error is less than 1% by testing in field.