Research On Infrared Focal Plane Detector's MTF,Crosstalk Testing Technology

MTF as an prominent parameter for valuing the imaging capabilities of imaging facility at different spatial frequencies,has greatly widespread and considerable applications.Crosstalk is the chief basic limiting the high-frequency MTF performance of IRFPA.Aiming at the MTF and crosstalk test requirements of IRFPA,this paper analyzes the noise distribution characteristics of the collected images,elements restricting OLS fitting,and the simplification of the test process,builds a more precise and convenient MTF and crosstalk test system.The collected infrared images involve various types of noise such as blind elements,non-uniformity,etc.,which makes the test results of MTF and crosstalk worse.Hence,these aspects are considered in this article.General image noise suppression uses median filtering.This way not only causes the decrease of edge information,but also has a weak ability to filter noise with small variance.In the proof,we kept trying to refine the noise suppression method.The converted median filter was used as the first filter for the noise with large variance,and then the BM3 D algorithm was used to restrain the residual noise.This is tested in MTF.Achieved very good results.The ESF fitting process of edge method.This article compares the fitting effects of polynomial fitting and Fermi fitting under different numbers of terms,and verifies the impression of some one-dimensional data smoothing methods on ESF,either Methods of weeding outliers.The crosstalk test is mainly to complete the alignment of the IRFPA and the condensed spot.In this regard,linear fitting and tracking are used to perform the tracking of the spot.The hardware units of the system mainly figure out the MTF component and diffraction limit of the optical portion,and completes the ZEMAX modeling of this portion;the detailed design of the overall system is limited by time and only part of the design content is completed.The overall goal is to achieve the software units.manipulated data demonstrate that the noise variance is greatly weakened,and the ESF data is not deformed.The maximum difference of edge angle detection in the target image of size400*400 does not outdo 0.5 degrees,and the data ESF curve fitting verifies that one item Fermi fitting has better stability,and the specific fitting parameters and weighted fitting can be used if necessary.Therefore,the contents of the experiment can be sumed up as follows:(1)Introduce the detailed test theory of MTF and crosstalk in IRFPA and give the characteristics of each method.(2)Combining the modified median filter with the BM3 D algorithm,multiple comparison experiments testify that variance of background only 12 percent of the original.(3)Through the optimization and improvement of ESF curve fitting parameters,the fitting error rate is finally reduced to 7%.If you want to judge whether to refit according to SSE,the error rate can be weiter ameliorated.The tracking of the crosstalk light spot coincides with the edge detection has deviation range in ±0.5 degrees.