Terahertz (THz) technology is increasingly being used in a wide range of applications, and terahertz radar systems have also been developed in radar applications. In this paper, the terahertz radar system is used for 2 dimensional (2D) realtime imaging in near-field scenario within 20m. A real-time imaging system of 170GHz Synthetic Aperture Radar (SAR) is designed, and the system is simulated and verified by Doppler Beam Sharpening (DBS) algorithm. The simulation results show that the system can utilize uniform linear motion to synthesize a short aperture in the near-field range and form 2D image of scattering points in the scene. The imaging effect is good.
The infrared radiation signature of exhaust plume from solid propellant rockets has been widely mentioned for its important realistic meaning. The content of aluminum powder in the propellants is a key factor that affects the infrared radiation signature of the plume. The related studies are mostly on the conical nozzles. In this paper, the influence of aluminum on the flow field of plume, temperature distribution, and the infrared radiation characteristics were numerically studied with an object of 3D quadrate nozzle. Firstly, the gas phase flow field and gas-solid multi phase flow filed of the exhaust plume were calculated using CFD method. The result indicates that the Al203 particles have significant effect on the flow field of plume. Secondly, the radiation transfer equation was solved by using a discrete coordinate method. The spectral radiation intensity from 1000-2400 cm-1 was obtained. To study the infrared radiation characteristics of exhaust plume, an exceptional quadrate nozzle was employed and much attention was paid to the influences of Al203 particles in solid propellants. The results could dedicate the design of the divert control motor in such hypervelocity interceptors or missiles, or be of certain meaning to the improvement of ingredients of solid propellants.