Analysis of the auxiliary capability of visible-infrared polarization information for rocket body observation under plume interference

The exhaust plume of a rocket is the primary source of interference for optical detection of the rocket body in the visible and infrared bands. Especially at critical observation angles such as large squint and tail-facing orientations, the plume can interfere with or obscure the rocket structure, leading to problems such as a sharp decline in the signal-to-noise ratio and deviation in the rocket body positioning in traditional intensity-based detection systems. As an optical feature independent of intensity, polarization has broad application prospects in revealing and distinguishing target characteristics. Based on the principle of polarized radiative transfer, this paper constructs a polarized radiative transfer model that comprehensively accounts for the radiative properties of solid surfaces and the characteristics of high-temperature gas-solid two-phase flows. Polarized radiative transfer simulations across the visible-IR spectrum are conducted to systematically investigate the feasibility of utilizing polarization features to mitigate plume interference, position rocket body under varying detection bands, plume particle sizes, flight altitudes, environmental conditions, observation angles, and spatial resolutions. The results demonstrate that polarization features can serve as effective complements to traditional intensity images under diverse conditions, enabling favorable positioning of the rocket body. Finally, the maximum detection distances of polarized light intensity (Ip) in the visible, short-wave infrared (SWIR), and mid-wave infrared (MWIR) bands are calculated for a flight altitude of 70 km, yielding values of 764.4 km, 1766.3 km, and 821.5 km, respectively. These results indicate that visible and infrared polarization information can serve as a supplement to intensity information and has potential application value for the positioning of rocket body.