Computer Simulation of Compensation Method for Infrared Focal Plane Array

A major motivation for this work is to investigate a method of computer simulation for compensating fixed pattern noise of the infrared focal plane arrays. A mathematical model of the output signal of focal plane array was established; a compensating algorithm utilizing reference source was derived and simulating programs were designed. The images of compensating process verify the influence of nonuniformity of responsibility and offset on fixed pattern noise. The result show that simulating method of investigating compensation technology for focal plane arrays is feasible, the generated images and methods can be used to the study of image recognition.

Testing System Based on Virtual Instrument for Readout Circuit of Infrared Focal Plane Array

Readout integrated circuit(ROIC) is one of the most important components for hybrid-integrated infrared focal plane array(IRFPA). And it should be tested to ensure the product yield before bonding. This paper presents an on-wafer testing system based on Labview for ROIC of IRFPA. The quantitative measurement can be conducted after determining whether there is row crosstalk or not in this system. This low-cost system has the benefits of easy expansion, upgrading, and flexibility, and it has been employed in the testing of several kinds of IRFPA ROICs to measure the parameters of saturated output voltage, non-uniformity, dark noise and dynamic range, etc.

A monolithic integrated medium wave Mercury Cadmium Telluride polarimetric focal plane array

A medium wave(MW)640×512(25μm)Mercury Cadmium Telluride(HgCdTe)polarimetric focal plane array(FPA)was demonstrated.The micro-polarizer array(MPA)has been carefully designed in terms of line grating structure optimization and crosstalk suppression.A monolithic fabrication process with low damage was explored,which was verified to be compatible well with HgCdTe devices.After monolithic integration of MPA,NETD<9.5 mK was still maintained.Furthermore,to figure out the underlying mechanism that dominat⁃ed the extinction ratio(ER),specialized MPA layouts were designed,and the crosstalk was experimentally vali⁃dated as the major source that impacted ER.By expanding opaque regions at pixel edges to 4μm,crosstalk rates from adjacent pixels could be effectively reduced to approximately 2%,and promising ERs ranging from 17.32 to 27.41 were implemented.

A substrate-free optical readout focal plane array with a heat sink structure

A substrate-ffee optical readout focal plane array （FPA） operating in 8-12 um with a heat sink structure （HSS） was fabricated and its performance was tested. The temperature distribution of the FPA with an HSS investigated by using a commercial FLIR IR camera shows excellent uniformity. The thermal cross-talk effect existing in traditional substrate-free FPAs was eliminated effectively. The heat sink is fabricated successfully by electroplating copper, which provides high thermal capacity and high thermal conductivity, on the frame of substrate-free FPA. The FPA was tested in the optical-readout system, the results show that the response and NETD are 13.6 grey/K （F / # = 0.8） and 588 inK, respectively.

New Dynamic Algorithm for IRFPA Bad Pixel Detection and Compensation Based on Statistics

Based on the analysis to the behavior of bad pixels, a statistics-based auto-detecting and compensation algorithm for bad pixels is proposed. The correcting process is divided into two stages： bad pixel detection and bad pixel compensation. The proposed detection algorithm is a combination of median filtering and statistic method. Single frame median filtering is used to locate approximate map, then statistic method and threshold value is used to get the accurate location map of bad pixels. When the bad pixel detection is done, neighboring pixel replacement algorithm is used to compensate them in real-time. The effectiveness of this approach is test- ed by applying it to I-IgCATe infrared video. Experiments on real infrared imaging sequences demonstrate that the proposed algorithm requires only a few frames to obtain high quality corrections. It is easy to combine with traditional static methods, update the pre-defined location map in real-time.

Adaptive nonuniformity correction for IRFPA sensors based on neural network framework

For infrared focal plane graded during signal acquisition array sensors, imagery is departicularly nonuniformity. In this paper, an adaptive nonuniformity correction technique is proposed which simultaneously estimates detector-level and readout- channel-level correction parameters using neural network approaches. Firstly, an improved neural network framework is designed to compute the desired output. Secondly, an adaptive learning rate rule is used in the gain and offset parameter estimation process. Experimental results show the proposed algorithm can achieve a faster convergence speed and better stability, remove nonuniformity and track parameters drift effectively, and present a good adaptability to scene changes and nonuniformity conditions.