The disruptive Impact of dynamic laser dazzling on template matching algorithms applied to thermal infrared imagery

Directed Infrared Countermeasure (DIRCM) systems are crucial for effective defence against modern infrared-guided threats. These systems provide significant advantages over traditional countermeasures, including rapid, precise, deep-magazine, and automatic response capabilities. These capabilities have the potential to thwart even the most advanced threats. However, realising this potential requires overcoming the problem of "home on jam," caused by a dazzled scene indicating the location of the laser from a simple profile. To address this issue, we propose a novel approach that considers dazzling as a dynamic property, aiming not to obscure the target completely but instead deceive the seeker through false targets. This paper assesses the impact of various approaches to confuse an infrared imager with the laser beam's varying spatial and temporal properties. We quantify the effect using scale-invariant template matching AI, comparing the similarity and the impact of laser and image properties on the effectiveness of in-band dazzling. Specifically, we use a Quantum Cascade Laser (QCL) with a peak wavelength of 4.6 microns to illuminate a thermal infrared imager within the 3 to 5 microns (MWIR) operating band. We project silhouette targets on the imager, representing aerial targets of interest, in the location of the imaged laser spot. Our findings highlight the importance of considering dynamic dazzle properties to overcome the home-on-jam problem. Our proposed approach shows promising results by utilising multiple targets and varying the spatial and temporal properties of the laser beam. We use several template-matching metrics to demonstrate the efficacy of our strategy and provide insights into how laser and image properties impact its effectiveness.