Researches On Target Detection Position And Attitude Of Optical Measurement

Optical measurement in aerospace measurement system refers to the traditional photogrammetry and newly developed digital tracking measuring techniques such as TV,infrared and laser,etc.Optical measurement equipment includes the photoelectric theodolite,photoelectric telescope and laser distance meter.The photoelectric theodolite and photoelectric telescope record the azimuth and elevation angle of a target in the stipulated coordinate system.The laser distance meter records the distance between the laser distance meter and the target.Its advantages include stability & reliability,high accuracy of measurement,convenient and intuitive observation,no increase in rocket body load,free of interferes from “blackout zone” and ground clutter,etc.Its disadvantages are short distance and easily affected by the weather.The optical measurement has high accuracy of measurement in the guaranteed precision segmental arc of missile and carrier rocket flight test,which generally distributes station and completes the missile rocket flight test task in cooperation with radio measuring equipment.The optical post-processing task is to obtain external ballistic parameters of a flying target in a specified coordinate system such as position,velocity and accelerated velocity,etc through mathematic calculations of data recorded by the optical equipment with the purpose of examining the gap between the aircraft design indicator and test flight,which has practical significance in improving the aircraft flight performance and range experiment comprehensive ability.Based on range optical measurement image preprocessing and follow-up data processing engineering application,this paper studies the techniques such as rocket target image information extraction,joint location of multi-measuring points target and rocket attitude determination,etc.which improves the reliability of optical measurement data post processing,reduces repetitive labor of staff and makes up the short coming of traditional algorithm in some extreme cases.Firstly,this paper introduces the optical measurement mean’s significance in flight telemetry & control as well as current situation of front-end measuring equipment and data post processing technique both at home and abroad.This paper introduces the data processing flow of practical task at present,including auxiliary information acquisition of measured picture,space-time registration and system error modification of optical equipment.It also introduces the classical algorithm of position and orientation briefly.Secondly,this paper analyzes the characteristics of rocket jet nozzle and flame as well as the judging principles,discusses the constraint equation and solving method of optical equipment’s measurement points(angle measurement and distance measurement)and pseudo range measurement points of GNSS.With respect to practical situation of complex range,smoggy and backlighting,it puts forward a joint orientation algorithm using rocket outline and cooperative measurement loop.This algorithm utilizes correlation between the target profile edge and measurement loop edge with cylinder rocket,which still acquires rocket’s attitude information under poor imaging situations.The method is proved to be effective in practical tasks.Finally,combining various algorithms and engineering practices with other classical methods of data post processing described above,this paper designs and implements an image interpretation system suitable for different image recording formats,which is capable of extracting picture auxiliary information such as time scale,angle measurement and distance measurement with other commonly used functions such as automatic interpretation and image playback,etc.It improves man-machine interaction based on the users’ opinions,which is highly appreciated by the users.