中继法解决再入航天器通信黑障问题优化研究

中继法是目前解决航天器再入通信黑障问题的一种可行方案,建立了背风面等离子鞘套模型,分析航天器再入俯仰角对信号在鞘套中的传输影响,并在航天器再入初始俯仰角下对比了S频段和Ka频段信号在背风面等离子鞘套的传输情况。结果表明:俯仰角越大,信号电磁波在等离子鞘套中的衰减越小;相同俯仰角下Ka频段传输性能明显优越于S频段信号,Ka频段信号相比于S频段信号,在背风面的透射率至少提高55%、衰减值至少降低33.69 dB,建议选用Ka频段信号作为中继卫星与再入航天器之间的通信频段并提出中继优化方案,为进一步解决航天器再入过程中的通信黑障问题提供思路。

Study on Solution about Re-entry Spacecraft Communications Blackout Problem by Relay Optimum Proposal

Currently, relay approach is a feasible scheme in solving the communication blackout problem when spacecraft reentries. This paper builds up a model of plasma sheath at leeward, analyzes influence of reentry spacecraft pitch angle on signal transmission in sheath, and contrasts the transmission of Ka-band signals with S-band signals in the leeward plasma sheath under initial pitch angle of the spacecraft reentry atmosphere. The result shows that the attenuation of signal electromagnetic wave in plasma sheath decreases with increase of pitch angle; under condition of the same pitch angle, the transmission of Ka-band signal is significantly superior to the transmission of S-band signal. Compared to S-band signal, Ka-band signal''s the transmissivity on leeward increases by at least 55%, with decrease on the attenuation by at least 33.69 dB. It''s suggested that Ka-band signal can be chosen as the communication frequency between reentry spacecraft and relay satellite. Relay approach is Proposed by relay optimum proposal, providing ideas to solve the reentry spacecraft communication blackout problems.