Addressing optical path maintenance need in infrared small target detection applications

Effective detection of small targets is crucial in infrared (IR) search and track systems, with image quality playing a key role in identifying IR small targets. For most applications, gain and offset corrections (2-point NUC) and bad pixel replacement (BPR) tables are set during production. Afterward, only updating offset corrections (1-point NUC) and BPR tables during use is typically sufficient for optimal performance. However, factorycalculated gain and BPR tables can become outdated after several cooldowns or extended storage. Additionally, focus shifts may lead to defocusing. This article proposes a two-stage method for determining optical path maintenance needs. The first stage addresses defocusing caused by focus shift, which weakens the target signal. The second stage evaluates changes in detector characteristics and the need for 2-point Non-Uniformity Correction (NUC) updates. Experimental results show that determining optical path maintenance needs is crucial for improving small target detection rates and reducing false alarms.