Analysis of plume at visible band and atmosphere background

Based on the Mie scattering theory, the spectral radiance of missile plume is calculated with the alumina particles model at the visible waveband of 400nm similar to 800nm. The software Modtran is used to simulate atmospheric transmission characteristics and atmospheric background radiation, obtain the transmittance of visible signals at different heights in the vertical direction of the atmosphere and the atmospheric background radiance of visible wavebands under different conditions. By analyzing the radiation transmission process, the radiation reception model of the detector was established to calculate the ratio of the number of electrons between the target signal and the atmospheric background noise at different heights. Then, based on the relevant parameters of the detector, the relationship between the signal-to-noise ratio (SNR) and the height and wavelength was calculated to evaluate the visible detection capability of the detector to the missile plume. It is analyzed that when the target height is greater than 10 km, the SNR in the same band tends to be constant and meets the detection requirements.Therefore, the visible sensor can theoretically be used to build imaging system for detecting the plume signal in the daytime.