Temporal stability and correctability of a MWIR T2SL focal plane array

Abstract

Stability over time has recently become a figure of merit of major importance to compare the performances of infrared focal plane arrays (FPA) of different technologies. Indeed, this parameter dictates how often the calibration of operational electro-optical systems has to be done, and thus reflects the availability of the system during an operational mission. Recent studies also showed that random telegraph signal (RTS) noise, which leads to flickering pixels, can strongly affect the image quality.The stability over time is generally estimated through fixed pattern noise (FPN) and residual fixed pattern noise (RFPN) measurements after a two-point correction. However, each laboratory or industrial has its own protocols and criteria, such that published results cannot be easily compared.In this paper, we describe our experimental protocol to evaluate the stability over time of a FPA and to count up/classify flickering pixels. We then present the results of two measurement campaigns realized on a T2SL MWIR Integrated Detector Dewar Cooler Assembly (IDDCA) provided by IRnova: the first, long term study was dedicated to the measurement of FPN/RFPN (estimated with two different algorithms); with the second study, dedicated to RTS noise, we tried to realize a classification of flickering pixels, based on the jump amplitude and the jump frequency. Our measurements show that the stability over time and correctability of the T2SL MWIR IDDCA are excellent.