Spectral radiation characteristics of high temperature gas in low altitude environment

In order to study the variation law of radiation characteristics of high temperature gas with altitude in medium and low altitude environment, the spectral radiation characteristics of three mixed gases containing H2O, CO2 and CO at different temperatures and pressures were calculated by LBL (Line by line) method, so as to analyze the corresponding changes of spectral radiation intensity of high temperature gas with the change of overall temperature and pressure, and explain the reason why the radiation spectrum changes with altitude. The results showed that the influence of temperature on the radiation intensity was more significant than that of pressure; at the same time, with the decrease of temperature, the peak value of spectral radiation gradually moved to the middle wave band, and the radiation intensity at 4.3 μm, which is the radiation band of CO2, and 4.7 μm, which is the radiation band of CO, gradually increased. However, due to the greater sensitivity of CO to the change of pressure, the relative radiation intensity at 4.7 μm after the pressure was reduced.