Infrared Signature Characteristics of Reentry Debris and Evaluation of Main-Body Discrimination Feasibility

This study investigates the infrared signature characteristics of debris generated during atmospheric reentry and evaluates the feasibility of discriminating such debris from the main body. Due to their small size and low thermal inertia, debris fragments exhibit rapid variations in surface temperature and radiative intensity with changing altitude, which often act as major sources of false alarms in EO/IR-based tracking systems. High-temperature flow fields and surface thermal responses were obtained through CFD analysis, and MWIR signatures were computed using MuSES. The results show that debris experiences a steep increase in heat flux and infrared intensity as altitude decreases, displaying significantly higher sensitivity to trajectory variations compared to the main body. These behaviors provide useful discriminative features for filtering debris-induced irregular signals and reducing false alarms in long-range detection and tracking. The findings can support the development of IR-based discrimination algorithms and enhance the effectiveness of reentry target surveillance systems.