Study On Radar Scattering Characteristics Of The Reentry Capsule

Based on the actual measuring data of C-band radar, the article made a systemic analysis on the mechanism of the plasma stealth of reentry target. Various branches of knowledge were used in this article such as reentry physics, theory of propagation of electromagnetic wave, characteristics of radar target.While the reentry target passes through the earth's atmosphere at ultrasonic speed, the RCS of the Reentry Capsule changed violently because of the plasma sheath and wake. The change in turn affected the ground -based radar. The increase of RCS of the reentry capsule is propitious to target recognition. The reduction of RCS of the reentry capsule resulted in temporary target loss. Synthetic analysis points out that there are three reasons of the target loss. One is the change of scattering of the reentry capsule. With the increase of the density of electrons in plasma wake, the scattering of the reentry capsule changed from volume scattering to surface scattering, which largely weakens the echo signal picked up by ground radar. The second reason is the refractive stealth of the target coated with non-uniform plasmas, which leads to the deviation of radar echo. The third reason is the energy attenuation during the transmission of radar wave in the plasma carried by the target. Under certain plasma collision frequency, the electromagnetic attenuation can further weaken the echo signal of the target. The article verified these theoretical analyses through specific calculations. The results are reasonable and credible.Since the plasma stealth is inevitable, the solution focused on reduction of the loss time. The recapture scheme is offered which used digital designation to help ground -based radar to catch target.The innovations of this paper include: Firstly, the inevitability of temporary target loss during the tracing of reentry capsule under the centimeter wave radar detecting technology is illustrated. Secondly, the integrated description of electromagnetic scattering characteristics of Reentry Capsule during the whole reentering process is presented.