摘要
由于现代星载雷达高度计采用了脉冲压缩技术,引入了电离层色散误差,在双频高度计的低频段该误差更明显.本文基于全去斜技术的理论模型,推导了这项误差的机理,提出可以把该误差等效为二次相位误差,并结合具体参数给出了分析的结果.本文还讨论了Chirp信号的多普勒误差对测高的影响.最后,作者通过计算机仿真得到了电离层色散效应对系统点目标响应的影响,对前面的结论进行了验证.
Radar altimeters selects full-deramp technology in pulse compression, and apply two frequencies to reduce the ionospheric range errors. These will, as this paper shows, introduce an effect called " Ionospheric Dispersion", especially in lower frequency, and this can lead to errors in height estimation. No foreign document is available to solve this problem, so this paper attempts to illustrate it. The authors finally draw the conclusion that these errors can be treated similarly as the quadratic phase errors, whose nature and solution are well-established, and that the magnitude of this error for a typical altimeter is also discussed. Furthermore, the actual Doppler errors are deduced and it is shown that the existent Doppler algorithms are adequately accurate. Finally, by computer simulation, the sidelobes introduced to the system point target response are illustrated and the errors are estimated.
出处
《中国科学院研究生院学报》
CAS
CSCD
2007年第2期235-240,共6页
Journal of the Graduate School of the Chinese Academy of Sciences
关键词
双频高度计
电离层色散效应
二次相位误差
点目标响应
dual-frequency altimeter, ionospheric dispersion, quadratic phase errors, point target response