Research About Test Technology Of LLL Image Intensifier S/N Ratio

The L.L.L.image intensifier is the key sensor of a L.L.L.night vision.It can increase the brightness of the faint image to be seen.The L.L.L.image intensifier is applied te many fields such as the L.L.L night vision,the ray radiation test,the photography,and se on.The S/N ratio is a very important performance specification for a L.L.L.image intensifier.This article is about the programming for the database and the test skills for the screen correction coefficient after the S/N ratio is test.The wave-filtrated Characteristic that the low-frequency can only pass for a L.L.L. image intensifier system mainly results in the screen correction coefficient,so the system can be regarded as a model of the linear low-frequency-pass filter.For this model,we can know the decreased power of the system by analyzing the power chart of the model with Fourier transform.Calculating the output signals can get the screen correction coefficient besides the original the S/N ratio test without any hardware added.In order to manage the database of the S/N ratio,a database has been used besides the previous software for the S/N ratio test.By Access database and ODBC visit,all the parameters,including time,type,serial number,S/N ratio,screen correction coefficient and so on,can be organized in a database.Some functions,such as canceling,refreshing, correcting,inserting,searching and so on,can be supplied.The experiment has proved the method for testing the screen correction coefficient. The test result is very close to what the manufacturer shows.This test method is very precise and reliable.Moreover,the added database is very convenient for the practical test.