Study of Statistical Narrow-Band Models for Infrared Signature of an Aeroengine Exhaust Plume in Mid-wave Infrared and Short-Wave Infrared Band

An aeroengine exhaust plume is one of the important sources of infrared (IR) signature in the 3-5 μm and the 2-3 μm bands. Analysis, characterization, and modeling of the exhaust plume IR emission are needed for insight into its role in aircraft survivability against IR-guided missiles. The IR signature estimation of aeroengine exhaust needs estimation of radiative properties of absorbing-emitting exhaust gases, e.g., carbon dioxide (CO₂) and water vapor (H₂O). The radiative properties of the gases can be estimated by a mathematical model with a spectroscopic database of these gases. Low-Resolution Transmission (LOWTRAN), Moderate-Resolution Transmission (MODTRAN), High-Resolution Transmission (HITRAN), and High-Temperature Transmission (HITEMP) are some commonly used spectroscopic databases. This study compares Statistical Narrow-Band (SNB) models with the various other mathematical models used for the estimation of radiative properties of exhaust gases. The contribution to IR signature due to constituents of engine plume is discussed.