Research on an innovative method of setting the integration time of cooled infrared focal plane array

Abstract

The integration time refers to the time for the infrared focal plane array (IRFPA) imaging system detector pixel that accumulate radiation signals to generate electrical signals. For the infrared seeker, in order to accurately capture the target, the integration time seriously affects the overall performance of the detection system, such as the output voltage, responsivity, noise equivalent temperature difference (NETD), and so on. This paper introduces the traditional method of setting the integration time, which is based on user’s experience and subjective judgment. This method often cannot give full play to the best performance of the detector. Moreover, because it’s highly subjective, different people may come up with different results. In order to make full use of the performance of the detector and obtain a consistent calibration effect, this paper proposes an integration time calibration method based on histogram and the response characteristics of the detector. And it is applied to the HgCdTe 640×512/15μm pitch MWIR. By comparison, after adopting the new method, the Residual fixed pattern noise (RFPN) and NETD of the device have been greatly improved after NUC. Compared with the traditional method, the new method can form a standardized process, and then provide guidance for the automatic calibration of IRFPA.