Development Of Infrared Target Simulator Calibration Technique

As the main qualification equipment of the radar test equipment and a lot ofother photoelectric equipments, etc, the calibration of IRTS has practical value toIRTS (IR Target Stimulator). Only IRTS with good performance could carry on theaccurate calibration. IRTS's calibration equipment enable the black body's centrestatus on focus position of parallel lamp by regulating its position in the parallellamp, so as to obtain parallel light beam of high quality, confirm the quality of thesimulator radiation performance of the infrared goal and carry on correspondingcalibration.IRTS's performance can be mainly considered by measuring RRP (Rayradiation power)absolutely, uniformity relatively, and measuring parallel degree.IRTS works normally when the three reach its standard at the same time.Measuring absolute RRP is the basic requirement for IRTS's conventionalcalibration technique. The light beam power uniform and parallel degree is theimportant aspects for evaluating the light beam's quality.The paper integrates themethods of RRP's relative measurement and parallel measurement.The designedoptic-electric measurement system can effectively measure and calibrate the IRTS.The paper is mainly constituted as following contents:1. Introduce IRTS's basic concept, describe the method and domestic andinternational research history and current situation of IRTS's calibration, and makebrief illustration to the relevant technology. Through the introduction of problemmeaning , expound its range of application and prospect .2. Based on blackbody radiation phenomenon and geometrical opticsprinciple , set up radiate models in the small sources, derive out the RRP in thelight-transmitting board and photoelectric detector electric current's calculationformulae, thus measure IRTS light beam power uniform at the light-transmittingboard. Aimming at the situation in computinging difficultly according to theformula directly, provide its corresponding progression form and work out thespecial-purpose software to calculate RRP.3. Design the overall scheme for this IRTS's calibration system. By using themethod of measuring RRP relatively at different position of IRTS's light beam, andthe method of measuring the facula position on the CCD, the developed IRTS'sCalibration System can respectively determine the light beam energy uniform andcalibrate its parallel degree. The developed IRTSCS is constituted of thedisplacement platform, pentaprism, measuring parallel light pipe, slot diaphragm,CCD, light-dividing mirror, photoelectric detector, light-transmitting board,singlechip, locking-phase enlarging circuit and PC .In order to solving chromaticdispersion problem of refraction system, especially long focus optics lens,measuring parallel light pipe is made by infrared light scene and visiable lightscene alternatively. Design the method to measure the light beam parallel degreeproduce by using CCD ,establish calculation relational expression between theblackbody's offset in horizontal and vertical direction and facula centroid's offset toorigin point in CCD ,and provide the parallel definition of degree and calculationformula. 4. Discuss the instrument design method for measuring the feeble light RRP.Set up noise model to photodiode and amplifier, guide selecting device type andapplication through analysis on equal noise model, put forward the scheme ofcarrying on the weak optical signal regarding lock-in amplifier circuit as the core.The circuit is comprised by photoelectric detector, preamplifier, full-scaleadjustment circuit, lock-in amplifier, post-amplifier, analogue digital converter(containing sample and hold function),and single-chip microcomputer. Throughdigital phase-shifting circuit which ia based on Resistor Set Oscillator to ensure thereference signal and signal has the same phase. 5. Choose interleaved, frame-shifted, two-dimensional monochrome CCD.More than one frame collected during every measurement to improve the signalnoise ratio. By making use of medium filtering,remove random noise.The key ofbinarization is to choose the proper threshold, the tipical threshold algorithmincludes mode algorithm, percentage algorithm, distinguishing algorithm,anddifferential histogram algorithm. Choose percentage algorithm to removeinterference of weak stray light. Combine morphology algorithm and spaceneighborhood judgement algorithm to adjudicate target, which can get rid of stronginterference of weak stray light. Consider that there is possibility that very strongstray light, adopt the artificial method to confirm the facula, thus improve thesystem's robustness. Get the facula's centroid by computing its center distance andcompute the parallel degree. 6. Describe IRTS Calibration Equipment position in the whole overallarrangement in the particular photo-electricity test equipment. Give the detailedsteps of zero calibration and detailed step of measurement. Carry on the experimentwith this optic-electric measurement system, and draw the experimental result,...