The Model Of Lll(low-light-level) Imaging System Performance Evaluation And The Research Of Simulation Software

As the main night vision technology, the Low-Light-Level(LLL) imaging system is an important part of the military and civilian.It becomes the photoelectric imaging technology for the development and equipment of the countries. In the process of designing the LLL imaging system, the designers alway want to design the system to have the best comprehensive performance.Characterized of the main parameters on the performance of LLL imaging system in addition to the resolution limit, modulation transfer function(MTF), signal to noise ratio(SNR) and horizon estimation,the Minimum Resolvable Contrast(MRC) and some new performance parameters are also considered effective evaluation method in recent years. Therefore, the study of the MTF, the MRC and the horizon estimation of the LLL imaging system are important for the theoretical evaluation of the performance of the LLL imaging system.Currently, although the study of LLL night vision system performance evaluation model has made significant progress, but in the practical application of related research units and individuals also because of the model of understanding is insufficient or because of the lack of unified evaluation tools. It makes that in some LLL night vision system is demonstrated and analyzed still use the earlier simple model suitable for hand calculations or the computational model is inconsistent.That often makes the argumentation and analysis results are not uniform. The accuracy difference between larger, the actual evaluation produced adverse effects.In order to solve this problem, this paper studies on the LLL imaging system performance model on Direct Viewing LLL imaging system and TV viewing LLL imaging system respectively. 1)With the study of MTF of LLL imaging system, analysised the super two generation and the three generation image intensifier’s MTF differences.Resulted out that fluorescent screen’s MTF has became the main factors that affect the image intensifier’s MTF and limit its resolution.2)Analysed and compared the existing MRC Model based on human eyes to obtain a more perfect MRC model.3)Through the study of the whole imaging process of LLL imaging system to obtain a more perfect horizon estimation model based on MRC model. 4) Combined with Visual C++ simulation of LLL night vision performance model.At the same time, an data-base is established, which collecting the parameters of imaging tubes.Finally according to the existing actual LLL night vision system performance parameters, using the simulation software to verify calculation, through analyzing and comparing the calculation data that simulation software can be used for engineering practice.