摘要
电离层色散导致穿过电离层传播的无线电脉冲信号畸变与失真,严重影响雷达系统对各种地面和空间目标的探测能力。考虑经过电离层传播的线极化雷达信号的相位色散和极化色散效应,参考他人工作推导了具有高斯幅度谱的发射信号与雷达接收信号的卷积包络的表达式,并分析计算了不同频率和相对带宽下接收包络的脉冲宽度和距离分辨率。结果表明:电离层色散效应随相对带宽的增加而增强,随雷达载频增大而减弱。对600 MHz以上载频,极化色散很弱;对100 MHz左右的载频信号,极化色散效应很明显,且强于常见的相位色散。相位色散对100 MHz^30GHz的雷达信号都有明显影响。
Radio pulse propagated through the ionosphere is distorted by the ionospheric dispersion effect and the radar performance for probing is seriously degraded. We investigate the ionospheric phase and polarization dispersion effect on linear polarization radar signal in this paper. The convolution envelope between the transmitted and the received signal is derived. Then we make analysis and calculation about the pulse duration and range resolution under different frequency and relative bandwidth. The results show that the dispersion effect becomes more serious when relative bandwidth increase or the signal frequency decrease. The polarization dis- persion is very weak when the carrier frequency is more than 600 MHz. The polarization dispersion is notable and stronger than the used phase dispersion when the carrier frequency is about 100 MHz. The phase dispersion is always notable even to the carrier frequency between 100 MHz and 30 GHz.
出处
《电波科学学报》
EI
CSCD
北大核心
2011年第1期30-34,共5页
Chinese Journal of Radio Science
基金
国家自然基金项目(No.40904040
61032009
60871076)
空间天气学国家重点实验室开放基金(O8262DAA4S)
关键词
电离层
雷达
相位色散
极化色散
ionosphere
radar
phase dispersion
polarization dispersion
